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1.
  • Kaiser, N. F. K., et al. (author)
  • Microwave-mediated palladium-catalyzed asymmetric allylic alkylation; an example of highly selective fast chemistry
  • 2000
  • In: Journal of Organometallic Chemistry. - Royal Inst Technol, Dept Chem Organ Chem, SE-10044 Stockholm, Sweden. Univ Uppsala, Uppsala Biomed Ctr, Dept Organ Pharmaceut Chem, SE-75123 Uppsala, Sweden.. - 0022-328X .- 1872-8561. ; 603:1, s. 2-5
  • Journal article (peer-reviewed)abstract
    • Highly enantioselective palladium-catalyzed microwave-mediated fast chemistry has been performed on dimethyl malonate alkylation of(rac)-1,3-diphenylallyl-1-acetate (1). Utilizing the recently developed palladium-phosphineoxazoline catalytic system, with general stability at elevated temperatures (less than or equal to 145 degrees C), quantitative yields of greater than or equal to 97% and ee values of up to >99% were obtained after very short irradiation times (15-300 s, TOF up to 7000 h(-1)).
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2.
  • Bahadorikhalili, Saeed, et al. (author)
  • N-sulfonyl ketenimine as a versatile intermediate for the synthesis of heteroatom containing compounds
  • 2021
  • In: Journal of Organometallic Chemistry. - : Elsevier. - 0022-328X .- 1872-8561. ; 939
  • Research review (peer-reviewed)abstract
    • The introduction of more facile and atom efficient methods for the synthesis of organic linear and cyclic compounds is the aim of various researchers worldwide. N-sulfonyl ketenimine is an interesting intermediate in modern organic synthesis. N-sulfonyl ketenimine is capable of selective production of various heteroatom containing compounds, based on the functional groups in the structure of this intermediate. Several linear and cyclic compounds are synthesized from this intermediate. In this review, the role of N-sulfonyl ketenimine is studied as an intermediate in several organic syntheses.
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3.
  • Belda, Oscar, et al. (author)
  • Chiral bispyridylamide metal complexes as catalysts for the enantioselective adddition of TMSCN to aldehydes
  • 2004
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X .- 1872-8561. ; 689:23, s. 3750-3755
  • Journal article (peer-reviewed)abstract
    • The use of (1R,2R)-N,N'-bis(2-pyridinecarboxyamido)-1,2-diphenylethane metal complexes as catalysts for the enantioselective addition of trimethylsilyl cyanide to aldehydes is described. Enantioselectivities up to 70% ee were obtained with a Ti(IV) catalyst. Complexes with Zr(IV), Sc(III), Yb(III) and Cu(II) afforded less selective catalysts. For the Zr(IV) complex, a rate and selectivity enhancement was observed when adding 0.5 equiv. of water with respect to the catalyst. Studies of the metal complexes involved in the reaction were carried out by means of H-1 NMR spectroscopy. A Zr complex was shown by X-ray crystallography to exhibit distorted octahedral coordination, with the four nitrogen atoms of the doubly deprotonated ligand essentially in one plane.
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4.
  • Cadu, Alban, et al. (author)
  • Development of iridium-catalyzed asymmetric hydrogenation : New catalysts, new substrate scope
  • 2012
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X .- 1872-8561. ; 714, s. 3-11
  • Research review (peer-reviewed)abstract
    • A review. The asym. hydrogenation of olefins is a tremendously powerful tool used to synthesize chiral mols. The field was pioneered using rhodium- and ruthenium- based catalysts; however, catalysts based on both of these metals suffer from limitations, such as the need for directing substituents near or even adjacent to the olefin. Iridium-based catalysts do not suffer from this flaw and can thus hydrogenate a wide variety of olefins, including some tetra substituted ones. It is also possible for iridium-based catalysts to hydrogenate hetero-π bonds such as those found in heteroarom. rings. This review summarizes the contributions made to this field by the authors in the past few years. [on SciFinder(R)]
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5.
  • Gao, Weiming, et al. (author)
  • Facile and highly efficient light-induced PR3/CO ligand exchange : A novel approach to the synthesis of (mu-(SCH2NPrCH2S)-Pr-n)Fe-2(CO)(4)(PR3)(2)
  • 2007
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X .- 1872-8561. ; 692:7, s. 1579-1583
  • Journal article (peer-reviewed)abstract
    • A straightforward and efficient transformation of the Fe-S complex [(mu-SCH2NPrCH2S)Fe-2(CO)(6)] to its double phosphine coordinated analogues [(mu-(SCH2NPrCH2S)-Pr-n)Fe-2(CO)(4)(PR3)(2)] (R = Ph, Me) is described. The single crystal structure of the PPh3-disubstituted Complex [(mu-(SCH2NPrCH2S)-Pr-n)Fe-2(CO)(4)(Ph3P)(2)] (3) showed that both of the phosphine ligands take an apical/apical instead of a basal/ basal or an apical/basal configuration.
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6.
  • Gerdin, Martin, 1976-, et al. (author)
  • Enantioselective silicon-boron additions to cyclic 1,3-dienes catalyzed by the platinum group metal complexes
  • 2008
  • In: Journal of Organometallic Chemistry. - : Elsevier B. V.. - 0022-328X .- 1872-8561. ; 693:23, s. 3519-3526
  • Journal article (peer-reviewed)abstract
    • Silaborations of 1,3-cyclohexadiene and 1,3-cycloheptadiene were achieved using catalysts prepared from different combinations of phosphorus ligands and group 10 metal compounds. For the six-membered compound, 1,4-adducts with up to 82% ee were obtained employing Pt(0) and phosphoramidite ligands. For the seven-membered diene optimal conditions were found using catalysts based on Ni(0), but the highest selectivity observed was merely 22% ee. No improvement of the chiral induction was obtained using chiral silylboranes in combination with chiral phosphoramidite ligands in the additions to 1,3-cyclohexadiene. The adduct obtained from cyclohexadiene was used in allylborations of aldehydes under microwave irradiation to produce homoallylic alcohols with moderate to good diastereoselectivity.
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7.
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8.
  • Hülsen, M., et al. (author)
  • Theoretical investigation of thermally and photochemically induced haptotropic rearrangements of chromium ligands on naphthalene systems
  • 2011
  • In: Journal of Organometallic Chemistry. - : Elsevier. - 0022-328X .- 1872-8561. ; 696:24, s. 3861-3866
  • Journal article (peer-reviewed)abstract
    • The description of chemical reactions by means of quantum mechanical methods is an important task and gets even more challenging if excited states have to be considered. This work focuses on the haptotropic rearrangements of chromium atoms bearing three coligands which migrate on a naphthalene-like system. The reactions are either thermally or photochemically controllable and thus the systems are candidates for molecular switches. We propose a detailed reaction scheme for the investigated system. Furthermore, we provide a detailed analysis of the important steps of the reaction cycle. In comparison to previous publications, the scope of this work also involves the quantum mechanical treatment of excited states in order to describe occurring photon absorption processes in a proper way. Linear response time-dependent density functional theory calculations were carried out to describe the molecules' responses to the external electromagnetic perturbations. 
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9.
  • Jimenez-Halla, J. Oscar C., et al. (author)
  • Organomagnesium clusters : Structure, stability, and bonding in archetypal models
  • 2011
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X .- 1872-8561. ; 696:25, s. 4104-4111
  • Journal article (peer-reviewed)abstract
    • We have studied the molecular structure and the nature of the chemical bond in the monomers and tetramers of the Grignard reagent CH(3)MgCl as well as MgX(2) (X = H, Cl, and CH(3)) at the BP86/TZ2P level of theory. For the tetramers, we discuss the stability of three possible molecular structures of C(2h), D(2h), and T(d) symmetry. The most stable structure for (MgCl(2))(4) is D(2h), the one for (MgH(2))(4) is C(2h), and that of (CH(3)MgCl)(4) is T(d). The latter is 38 kcal/mol more stable with chlorines in bridge positions and methyl groups coordinated to a Mg vertex than vice versa. We find through a quantitative energy decomposition analysis (EDA) that the tetramerization energy is predominantly composed of electrostatic attraction Delta V(elstat) (60% of all bonding terms Delta V(elstat) + Delta E(oi)) although the orbital interaction Delta E(oi) also provides an important contribution (40%).
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10.
  • Johansson, A, et al. (author)
  • Chiral diethylzinc complexes with diamine ligands : synthesis, crystal structure and enantioselective solvent-free alkylation
  • 2005
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X .- 1872-8561. ; 690:16, s. 3846-3853
  • Journal article (peer-reviewed)abstract
    • In search for conglomerates of stereochemically labile organometallic reagents, three new complexes between diethylzinc and diamine ligands have been synthesized and structurally characterized by single-crystal X-ray diffraction methods. Ligands include N,N,N',N'-tetraethylethylenediamine (teeda), N-isopropyl-N,N',N'-trimethylethylenediamine (itmeda), and (-)-sparteine (spa). Diethylzinc forms monomeric complexes, exhibiting a distorted tetrahedral coordination geometry around zinc in all three complexes, viz. [ZnEt(2)(teeda)] (1), [ZnEt(2)(itmeda)] (2), and [ZnEt(2)(spa)] (3). Both 1 and 2 are stereochemically labile and exhibit chiral complexes, displaying different types of conformational chirality, but they form racemic crystals. By using the chiral crystals of 3 in a nucleophilic addition to benzaldehyde in the absence of solvent at low temperature, an increase in ee from approximately 8 to 10% was obtained (compared to the same reaction in solution). It thus seems feasible, not only to retain the enantioselectivity obtained in solution, but perhaps even to increase the ee by using solventless reactions.
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11.
  • Li, Cheng, et al. (author)
  • Photochemical hydrogen production catalyzed by polypyridyl ruthenium-cobaloxime heterobinuclear complexes with different bridges
  • 2009
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X .- 1872-8561. ; 694:17, s. 2814-2819
  • Journal article (peer-reviewed)abstract
    • Two heterobinuclear complexes [(bpy)(2)Ru(bpy-4-CH3,4'-CONH(4-py)Co(dmgBF(2))(2)(OH2)](PF6)(2) (1, dmgBF(2) = (difluoroboryl) dimethylglyoximato) and [(bpy)(2)Ru(bpy-4-CH3,4'-CONHCH2(4-py)Co(dmgBF(2))(2)(OH2)](PF6)(2) (2) were prepared, in which the polypyridyl ruthenium photosensitizer and the cobaloxime catalyst are connected either by a conjugated bridge (1) or by an unconjugated one (2). Complexes 1 and 2 were used as photocatalysts for hydrogen generation. Under optimal conditions, the turnover numbers (ton) for hydrogen evolution were 38 for 1 and 48 for 2 in the presence of 300 equiv of both Et3N and [Et3NH][BF4] in the acetone solution during an 8-h irradiation of visible light (lambda > ca. 400 nm). The complex 2 with an unconjugated bridge proved to be more efficient for photochemical hydrogen generation than the complex 1 with a conjugated bridge under the same reaction condition.
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12.
  • Li, Minna, et al. (author)
  • Aryl-diamide bridged binuclear ruthenium(II) tris(bipyridine) complexes : Synthesis, photophysical, electrochemical and electrochemiluminescence properties
  • 2006
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X .- 1872-8561. ; 691:20, s. 4189-4195
  • Journal article (peer-reviewed)abstract
    • Several new symmetrical aromatic hydrocarbon bridged bipyridine ligands and their binuclear Ru (II) complexes have been designed, synthesized and characterized on the basis of H-1 NMR, MS and HRMS. Their absorption and emission properties, electrochemical behaviors and electrochemical luminescence were investigated. All ruthenium complexes show characteristic MLCT absorption and similar redox potential. Among the three complexes reported, 4c has the best electrochemical luminescence property.
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13.
  • Li, Minna, et al. (author)
  • Oligo thiophene-2-yl-vinyl bridged mono- and binuclear ruthenium(II) tris-bipyridine complexes : Synthesis, photophysics, electrochemistry and electrogenerated chemiluminescence
  • 2008
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X .- 1872-8561. ; 693:1, s. 46-56
  • Journal article (peer-reviewed)abstract
    • A series of mono- and binuclear ruthenium(II) tris-bipyridine complexes tethered to oligothienylenevinyleries have been synthesized and characterized by H-1 NMR, C-13 NMR and TOF-MS spectrometry. Photophysics, electrochemistry and electrogenerated chemiluminescence (ECL) properties of these complexes are investigated. The electronic absorption spectra of the mononuclear ruthenium complexes show a significant red shift both at MLCT (metal-to-ligand charge transfer) and pi-pi* transitions of oligothienylenevinylenes with increase in the number of thiophenyl-2-yl-vinyl unit. For the binuclear complexes these two absorption bands are overlapped.) All the metal complexes have very weak emission compared to that of the reference complex Ru(bpy)(3)(2+). The first reduction potentials of all mononuclear ruthenium complexes are less negative than that of Ru(bpy)(3)(2+), due to the moderate electron-withdrawing effect of oligothienylenevinylenes. For binuclear ruthenium complexes, only one Ru(II/III) oxidation peak (E-1/2=0.96V vs. Ag/Ag+) was observed, suggesting a weak interaction between two metal centers. Three successive reduction processes of bipyridine ligands are similar among all ruthenium complexes except for RuTRu, which has a very sharp peak owing to the accumulation of neutral product oil the electrode surface. All these ruthenium complexes exhibited different ECL property in CH3CN solution without any additional reductant or oxidant. For three mononuclear ruthenium complexes, the ECL intensity strengthens with increase in the number of thiophene-2-yl-vinyl unit. However, the ECL efficiency dramatically decreased in the binuclear ruthenium complexes. The ECL efficiencies of all the)2+, reported complexes do not exceed that of Ru(bpy 3 where the ECL efficiency decreases in the order of RuTRu > Ru3T > Ru2T > RuT > Ru2TRu (RuT, bis-2,2'-bipyridyl-(4-metliyl-4'-(2-thienylethenyl)-2,2'-bipyridine) ruthenium dihexafluorophosphate; Ru2T, bis-2,2'-bipyridyl-(4-methyl-4'-{(E) -2-[5-((E) -2-thienylethenyl)-thienylethenyl])-2,2'-bipyridine)ruthenium dihexafluorophosphate; Ru3T, bis-2,2'-bipyridyl-(4-methyl-4'-[(E)-2-{(E)-2-[5-((E)-2-thienylethenyl)- thienylethenyl])}-2,2'-bipyridine) ruthenium dihexafluorophosphate; RuTRu, bis-2,2'-bipyridyl-ruthenium-bis-[2-((E)-4'-methyl-2,2'-bipyridinyl-4)-e thenyl]-thienyl-bis-2,2'-bipyridyl-ruthenium tetrahexafluorophosphate; Ru2TRu, bis-2,2'-bipyridyl-ruthenium-(E)-1,2-bis-{2-[2-((E)-4'-methyl-2,2'-bipyr idinyl-4)-ethenyl]-thienyl}ethenyl-bis-2,2'-bipyridyl-ruthenium tetrahexafluorophosphate).
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14.
  • Na, Yong, et al. (author)
  • An approach to water-soluble hydrogenase active site models : Synthesis and electrochemistry of diiron dithiolate complexes with 3,7-diacetyl-1,3,7-triaza-5-phosphabicyclo 3.3.1 nonane ligand(s)
  • 2006
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X .- 1872-8561. ; 691:23, s. 5045-5051
  • Journal article (peer-reviewed)abstract
    • In order to improve the hydro- and protophilicity of the active site models of the Fe-only hydrogenases, three diiron dithiolate complexes with DAPTA ligand(s) (DAPTA=3,7-diacetyl-1,3,7-triaza-5-phosphabicyclo[3.3.1]nonanc), (mu-pdt)[Fe(CO)(2)][Fe(CO)(2)(DAPTA)] (1, pdt = 1,3-propanedithiolato), (mu-pdt)[Fe(CO)(2)(DAPTA)](2) (2) and (mu-pdt)[Fe(CO)(2)(PTA)][Fe(CO)(2)(DAPTA)] (3), were prepared and spectroscopically characterized. The water solubility of DAPTA-coordinate complexes 1-3 is better than that of the PTA-coordinate analogues. With complexes 1-3 as electrocatalysts, the overvoltage is reduced by 460-770 mV for proton reduction from acetic acid at low concentration in CH3CN. Significant decrease, up to 420 mV, in reduction potential for the Fe(I)Fe(I) to Fe(I)Fe(0) process and the curve-crossing phenomenon are observed in cyclic voltammograms of 2 and 3 in CH3CN/H2O mixtures. The introduction of the DAPTA ligand to the diiron dithiolate model complexes indeed makes the water solubility of 2 and 3 sufficient for electrochemical studies in pure water, which show that the proton reduction from acetic acid in pure water is electrochemically catalyzed by 2 and 3 at ca. -1.3 V vs. NHE.
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15.
  • Ning, Zhijun, et al. (author)
  • Novel iridium complex with carboxyl pyridyl ligand for dye-sensitized solar cells : High fluorescence intensity, high electron injection efficiency?
  • 2009
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X .- 1872-8561. ; 694:17, s. 2705-2711
  • Journal article (peer-reviewed)abstract
    • Novel iridium-based sensitizers Iridium(III) bis[2-phenylpyridinato-N,C-2']-5-carboxylpicolinate) (Ir1), Iridium(III) bis[2-(naphthalen-1-yl) pyridinato-N,C-2']-5-carboxyl-picolinate) (Ir2), Iridium(III) bis[2-phenylpyridinato-N, C-2']-4,4'-(dicarboxylicacid)-2,2'-bipyridine (Ir3) were synthesized for sensitization of mesoscopic titanium dioxide injection solar cells. By changing the ligand, the absorption spectra can be extended and molar extinction coefficient was enhanced. The dye-sensitized nanocrystalline TiO2 solar cells (DSSCs) based on dye Ir3 showed the best photovoltaic performance: a maximum monochromatic incident photon-to-current conversion efficiency (IPCE) of 85%, a short-circuit photocurrent density (J(sc)) of 9.59 mA cm (2), an open-circuit photovoltage (V-oc) of 0.552 V, and a fill factor (ff) of 0.54, corresponding to an overall conversion efficiency of 2.86% under AM 1.5 sun light. Moreover, the HOMO and LUMO energy levels tuning can be conveniently accomplished by alternating the ligand. The high oxidative potential of Ir3 enables it to be used along with Br-/Br-3(-) redox electrolyte and the photovoltage was found to be enhanced greatly.
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16.
  • Posevins, Daniels, 1990-, et al. (author)
  • Iron-catalyzed cross-couplings of propargylic substrates with Grignard reagents
  • 2022
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X .- 1872-8561. ; 964
  • Journal article (peer-reviewed)abstract
    • One of the main challenges of modern chemical industry is the inevitable transition to greener, more sustainable manufacturing processes that utilize raw materials more effectively, minimize waste streams, and avoid the use of toxic and hazardous materials. The development of new iron-based catalytic systems can eliminate the need for the currently widely used, costly and potentially toxic heavy metal catalysts in industrially relevant chemical reactions. Prominent examples of such processes include transition metal catalyzed cross-coupling reactions for formation of carbon-carbon (C -C) bonds. This minireview outlines recent developments in the area of iron-catalyzed cross-coupling chemistry during the last couple of decades, with special emphasis on the use of propargylic substrates and Grignard reagents as coupling partners.
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17.
  • Saeed, Aamer, et al. (author)
  • Advances in transition-metal-catalyzed synthesis of 3-substituted isocoumarins
  • 2017
  • In: Journal of Organometallic Chemistry. - : ELSEVIER SCIENCE SA. - 0022-328X .- 1872-8561. ; 834, s. 88-103
  • Research review (peer-reviewed)abstract
    • 3-Substituted isocoumarins are the most abundant class of naturally isocoumarins, found in several biologically active scaffolds and are precursors towards complex natural products. Considerable attempts have been devoted to the synthesis of these isocoumarins both by metal free or transition-metalcatalyzed reactions. Among the metal catalyzed reactions, the use of palladium, copper, gold, iron, nickel, rhodium, ruthenium, zinc, chromium, iridium, silver or thallium salts/complexes for the construction of 3-substituted isocoumarin ring is noteworthy due to being economical and good functional group tolerance. The current review focusses the recent reports on the Pd-, Cu-, Ag-, Fe-, Ni-, Rh-, Ru-, Zn, Cr-, Ir-, Ag- and Ti -catalyzed synthesis of isocoumarins.
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18.
  • Samec, Joseph S. M., et al. (author)
  • Latent ruthenium olefin metathesis catalysts featuring a phosphine or an N-heterocyclic carbene ligand.
  • 2010
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X .- 1872-8561. ; 695:14, s. 1831-1837
  • Journal article (peer-reviewed)abstract
    • The synthesis and characterization of latent 18-electron ruthenium benzylidene complexes (PCy3)((κN,O)-picolinate)2RuCHPh (5) and (H2IMes)((κN,O)-picolinate)2RuCHPh (6) are described. Both complexes appear as two isomers. The ratio between the isomers is dependent on L-type ligand. The complexes are inactive in ring-closing metathesis and ring-opening metathesis polymn. reactions even at elevated temps. in the absence of stimuli. Upon addn. of HCl, complexes 5 and 6 become highly active in olefin metathesis reactions. The advantage of the latent catalysts is demonstrated in the ring-opening metathesis polymn. of dicyclopentadiene, where the latency of 6 assures adequate mixing of catalyst and monomer before initiation. Trapping expts. suggests that the acid converts the 18-electron complexes into their corresponding highly olefin metathesis active 14-electron benzylidenes. [on SciFinder(R)]
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19.
  • Schaffran, Tanja, et al. (author)
  • Dodecaborate cluster lipids with variable headgroups for boron neutron capture therapy : Synthesis, physical-chemical properties and toxicity
  • 2009
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X .- 1872-8561. ; 694:11, s. 1708-1712
  • Journal article (peer-reviewed)abstract
    • We have prepared two new boron-containing lipids with potential use in boron neutron capture therapy of tumors. These lipids consist of a diethanolamine frame with two myristoyl chains bonded as esters, and a butylene or ethyleneoxyethylene unit linking the doubly negatively charged dodecaborate cluster to the amino function of the frame, obtained by nucleophilic attack of the amino on the tetrahydrofurane and dioxane derivatives, respectively, of closo-dodecaborate. The latter cluster lipid can form liposomes at 25 °C whereas the former lipid at this temperature assembles into bilayer disks. Both lipids form stable liposomes when mixed with suitable helper lipids. The thermotropic behavior was found to be different for the two lipids, with the butylene lipid showing sharp melting transitions at surprisingly high temperatures. Toxicity in vitro and in vivo varies greatly, with the butylene derivative being more toxic than the ethyleneoxyethylene derivative.
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20.
  • Strand, Daniel, et al. (author)
  • [(BINAP)Re(O)Cl-3] as an efficient catalyst for olefination of chiral alpha-substituted aliphatic aldehydes
  • 2010
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X .- 1872-8561. ; 695:19-20, s. 2220-2224
  • Journal article (peer-reviewed)abstract
    • A convenient one-pot preparation of [(BINAP) Re(O)Cl-3] (6) is described. This complex was demonstrated to be an efficient catalyst for the olefination of aldehydes by reaction with alpha-diazo esters, with essentially quantitative yields and up to 98:2 geometric selectivity. The potential for using enantiopure [(BINAP)Re(O)Cl-3] (6) to promote an asymmetric kinetic resolution of racemic alpha-stereogenic aldehydes was investigated, but no enantiotopic discrimination was observed. Control experiments indicate that this lack of selectivity stems from the in-situ formation of a phosphonium ylide, which accounts for product formation in a non-metal associated reaction pathway.
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21.
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22.
  • Tran, Lien-Hoa, et al. (author)
  • A new square planar mononuclear Mn-III complex for catalytic epoxidation of stilbene
  • 2008
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X .- 1872-8561. ; 693:6, s. 1150-1153
  • Journal article (peer-reviewed)abstract
    • The manganese(III) complex (2) with a diamide ligand has been synthesized. This complex was found to catalyze both the epoxidation of (Z)- and (E)-stilbene with high conversion and the oxidation of benzyl alcohol to benzaldehyde.
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23.
  • Wang, M., et al. (author)
  • Salen-type zirconium complexes with a labile coordination site and a robust skeleton : crystal structure of (t-Bu-4-salen)ZrCl2(H2O)
  • 2004
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X .- 1872-8561. ; 689:7, s. 1212-1217
  • Journal article (peer-reviewed)abstract
    • Treatment of LZrCl2 (L - N, N'-ethylenebis(3,5-di-tert-butylsalicylideneiminato) (1), N, N'-o-phenylenebis(3,5-di-tert-butylsalicylideneiminato) (2)), which is an effective catalyst precursor for ethylene oligomerization, with 1.5 equiv of water in toluene afforded H2O-coordinating salen-type zirconium complexes [LZrCl2(H2O)]. The effects of the content of H2O and the temperature on the equilibrium of association and disassociation of H2O molecule in [LZrCl2(H2O)(n)] (n = 0, 1) were studied in solution (CDCl3) by H-1 NMR spectroscopy. The crystal and molecular structure of [1(H2O)] was determined by X-ray diffraction analysis, which revealed that a herringbone supramolecular assembly was constructed in the crystalline state of [1(H2O)], stacked by the intermolecular hydrogen bonds between the OH group of the coordinating H2O and one of the chloride ligands.
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24.
  • Wang, Zhen, et al. (author)
  • Azadithiolates cofactor of the iron-only hydrogenase and its PR3-monosubstituted derivatives : Synthesis, structure, electrochemistry and protonation
  • 2007
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X .- 1872-8561. ; 692:24, s. 5501-5507
  • Journal article (peer-reviewed)abstract
    • The core structure (mu-SCH2)(2)NH[Fe-2(CO)(6)](5) of Fe-only hydrogenases active site model has been synthesized by the condensation of iron carbonyl sulfides, formaldehyde and silyl protected amine. Its monosubstituted complexes (mu-SCH2)(2)NH[Fe-2(CO)(5)PR3] (R = Ph (6), Me (7)) were accordingly prepared. The coordination configurations of 5 and 6 were characterized by X-ray crystallography. Protonation of complex 7 to form the N-protonated product occurs in an acetonitrile solution upon addition of triflic acid. The redox properties of these model complexes were studied by cyclic voltammetry.
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25.
  • Wang, Zhen, et al. (author)
  • Pendant bases as proton transfer relays in diiron dithiolate complexes inspired by Fe-Fe hydrogenase active site
  • 2008
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X .- 1872-8561. ; 693:17, s. 2828-2834
  • Journal article (peer-reviewed)abstract
    • Three dinuclear iron complexes containing pendant nitrogen bases in phosphine ligands with general formular ( l- pdt) [ Fe2( CO) 5L] ( where pdt is SCH2CH2CH2S, L = PPh2NH( CH2) 2N( CH3) 2 ( 5), PPh2NH( 2- NH2C6H4) ( 6), PPh2[ 2- N( CH3) 2CH2C6H4] ( 7)), were prepared as the models of the [ Fe - Fe] hydrogenase active site. The molecular structures of 5 - 7 were characterized by X- ray crystallography. The secondary amine in 6 has weak intramolecular hydrogen bonding with both the terminal nitrogen and sulfur atom, which may suggest a proton transfer pathway from amine in phosphine ligand to the sulfur atom of active site. Protonation of complexes 5 and 6 only occurred at the terminal nitrogen atom. Electrochemical properties of the complexes were studied in the presence of tri. ic acid by cyclic voltammetry.
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26.
  • Zhao, Zhenbo, et al. (author)
  • Synthesis and characterization of carboxy-functionalized diiron model complexes of FeFe -hydrogenases : Decarboxylation of Ph2PCH2COOH promoted by a diiron azadithiolate complex
  • 2009
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X .- 1872-8561. ; 694:15, s. 2309-2314
  • Journal article (peer-reviewed)abstract
    • Two carboxy-functionalized diiron complexes [{(mu-SCH2)(2)X}{Fe(CO)(3)}{Fe(CO)(2)L}] (X = NC3H7, L = Ph2PCH2CH2COOH, 4; X = CH2, L = Ph2PCH2COOH, 5) were prepared, as biomimetic models of the [FeFe] hydrogenase active site, from the CO-replacement of [{(mu-SCH2)(2)NC3H7}Fe-2(CO)(6)] (1) and (mu-pdt)Fe-2(CO)(6) (2) by phosphine ligands in CH3CN at 40 degrees C, respectively. In contrast, the reaction of 1 with Ph2PCH2COOH under the same condition afforded complex [{(mu-SCH2)(2)NC3H7}{Fe(CO)(3)}{Fe- (CO)(2)(Ph2PCH3)}] (3) with a decarboxylated phosphine ligand. The molecular structures of complexes 3-5 were determined by X-ray crystallographic analyses, which show that they have similar frameworks with the phosphine ligand on the apical position. The interesting C-H center dot center dot center dot S contacts between the methylene hydrogen atoms of the PhCH2COOH ligand and the mu-S atoms of the pdt-bridge are found in the crystal of 5. According to the experimental evidence, a plausible mechanism, via sequential phosphine coordination, N-protonation, and decarboxylation steps, is proposed for the formation of 3 and for explanation of the contrastive reactivities of the adt- (2-aza-1,3-propanedithiolato) and the pdt-(1,3-propanedithiolato) bridged diiron complexes toward decarboxylation of the Ph2PCH2COOH ligand.
  •  
27.
  • Zhu, H. J., et al. (author)
  • Preparation and structures of 6-and 7-coordinate salen-type zirconium complexes and their catalytic properties for oligomerization of ethylene
  • 2005
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X .- 1872-8561. ; 690:17, s. 3929-3936
  • Journal article (peer-reviewed)abstract
    • A series of salen-type zirconium complexes of the general formula LZrCl2 (L = N,N '-ethylenebis(salicylideneiminate), 3a; N,N '-ethylenebis(3,5-di-tert -butylsalicylideneiminate), 3b; N,N '-ethylenebis(5-methoxysalicylidenciminate), 3e; N,N '-o-phethylenebis(5-chlorosalicylideneiminate), 3d; N,N '-ethylenebis(5-nitrosalicylideneiminate), 3e; N,N '-o-phenylenebis(salicylideneiminate), 4a; N,N '-o-phenylenebis(3,5-di-tert-butylsalicylideneiminate), 4b; N,N '-o-phenylenebis(5-methoxysalicylideneiminate), 4c; N,N '-o-phenylenebis(5-chloro-salicylideneiminate), 4d) were prepared. The crystal structures of 6- and 7-coordinate zirconium complexes 4b and [4b center dot OCMe2] were determined by X-ray crystallography, which reveals that a salen-type zirconium complex possesses a labile coordination site on the Zr center with a relatively stable framework and that the coordination and the dissociation of O-donor molecules occur readily at this site. The catalytic properties of 3(a-e) and 4(a-d) were studied for ethylene oligomerization in combination with Et2AlCl as co-catalyst. Complex 3c featuring a methoxy-substituted salen ligand displayed higher activity than its analogous precursors having chloro and nitro groups as substituents. The catalytic reactions by 3(a-e) and 4(a-d) gave C-4-C-10 olefins and low-carbon linear (alpha-olefins in good selectivity.
  •  
28.
  • Åkerstedt, Josefin, et al. (author)
  • Synthesis and characterization of binuclear palladium(I) compounds and the influence of competing arenes
  • 2010
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X .- 1872-8561. ; 695:10-11, s. 1513-1517
  • Journal article (peer-reviewed)abstract
    • The binuclear palladium(I) compounds, [Pd-2(Ga2Cl7)(2)(C7H8)(2)] (1), [Pd-2(GaCl4)(2)(C9H12)(2)]center dot C9H12 (2) and [Pd-2(Ga2Cl7)(2)(C6H5Cl)(2)] (3), have been prepared from palladium(II) chloride in gallium(III) chloride-arene reaction media. All isolated crystalline solids (1, 2 and 3) have been structurally characterized by single crystal X-ray diffraction and Raman spectroscopy. The results form quantum chemical calculations on the interaction energies of the arenes and the dipalladium unit of these compounds is also presented.
  •  
29.
  • Gustafsson, Björn, 1970, et al. (author)
  • A tetrameric copper(I) alkoxide with a pi-tethered ligand: 2-allyl-6-methylphenoxocopper(I)
  • 2002
  • In: Journal of Organometallic Chemistry. - 0022-328X. ; 649:2, s. 204-208
  • Journal article (peer-reviewed)abstract
    • The complex 2-allyl-6-methylphenoxocopper(I) has been prepared by reaction between mesitylcopper(I) and 2-allyl-6-methylphenol. Crystallographic studies show that the compound is tetrameric with a distorted cubane-type copper(I)-oxygen core, and with additional pi-coordination of the ligand to copper through the alkene functionality (nu(C=C)=1520 cm(-1)). The ligands thus act both as chelates and as bridges between adjacent copper(l) centres. Copper(l) exhibits trigonal pyramidal coordination geometry with Cu-C distances to the C=C group of 1.976(9) and 2.017(11) Angstrom and Cu-O distances of 1.973(6), 2.021(6) and 2.577(6) Angstrom, respectively.
  •  
30.
  • Håkansson, Mikael, 1957, et al. (author)
  • Aurophilic association in endo-dicyclopentadienechlorogold(I)
  • 2000
  • In: Journal of Organometallic Chemistry. - 0022-328X. ; 602:1-2, s. 133-136
  • Journal article (peer-reviewed)abstract
    • The complex between endo-dicyclopentadiene and gold(I) chloride has been prepared by a substitution reaction in dichloromethane, whereby carbon monoxide in dissolved [AuCl(CO)] has been displaced by the endo-dicyclopentadiene ligand. This ligand is eta(2)-bonded to gold(I) via the C=C bond in the norbornene ring. Crystallographic studies show that the [AuCl(C10H12)] moiety undergoes aurophilic association to form a [(AuCl(C10H12))(2)] dimer, in which the Au-Au distance is 3.4282(8) Angstrom.
  •  
31.
  • Håkansson, Mikael, 1957, et al. (author)
  • Copper(I) complexes with conjugated dienes
  • 2000
  • In: Journal of Organometallic Chemistry. - 0022-328X. ; 602:1-2, s. 5-14
  • Journal article (peer-reviewed)abstract
    • Three copper(I) complexes containing conjugated dienes and one containing the acetylenic analogue of isoprene, 2-methyl-1-butene-3-yne (isopropenylacetylene), have been prepared and characterised by means of crystal-structure determination. Direct reaction between isoprene (2-methylbutadiene) and copper(I) trifluoromethylsulfonate, using triphenylphosphine as a stabilising ligand, results in [Cu-2(PPh3)(2)(mu-(H2C=CHC(CH3)=CH2))(O3SCF3)(2)] (1), whereas reaction between copper(I) chloride and isopropenylacetylene, dimethylbutadiene, and trans-1,3-pentadiene yields the labile compounds [Cu2Cl2 (mu-(H2C=CHC(CH3)=CH))] (2), [Cu2Cl2 (mu-(H2C=C(CH3)C(CH3)-CH2))] (3) and [Cu2Cl2(mu-(trans-H2C=CHCH=CH(CH3))] (4), respectively. All four compounds are polymeric. Thus, the organic ligands bridge two copper(I) centres via the alkene or alkyne bonds, the conjugated dienes all assuming the s-trans conformation. Further bridging is effected by the trifluoromethylsulfonate ligands in 1 and by the chloride ligands in 2, 3 and 4. In 1, copper(I) has distorted tetrahedral geometry, whereas in 2, 3 and 4, copper(I) exhibits tetrahedral or trigonal pyramidal geometry with the C=C/C=C linkage in the trigonal plane and an apical Cu-Cl bond. The nearly planar carbon skeleton of isoprene in 1 bonds to two copper(I) atoms from opposite faces of the diene. The Cu-C distances range from 2.085(6) to 2.220(6) Angstrom [C(CH3)] and the C=C bond lengths are 1.360(8) and 1.353(8) Angstrom. Trifluoromethylsulfonate ligands bridge adjacent [Cu-2(PPh3)(2)(mu-(H2C=CHC(CH3)-CH2))(O3SCF3)(2)] units leading to the formation of chains, containing internal chair-shaped Cu2S2O4 rings alternating with isoprene ligands, with peripheral triphenylphosphine ligands. The carbon skeleton of the isopropenylacetylene ligand in 2 and those of dimethylbutadiene in 3 and of trans-1,3-pentadiene in 4 are also approximately planar, but, unlike the situation in 1, in compounds 2-4, two copper(I) atoms are coordinated by C=C/C=C from the same face of the ligand. In 2, Cu-C distances range from 2.005(11) to 2.158(9) Angstrom [C(CH3)] and the C=C and C=C bond lengths are 1.373(13) and 1.200(14) Angstrom, respectively. In 3, Cu-C distances range from 2.06(1) to 2.17(1) Angstrom [C(CH3)] and both C=C bonds are 1.35(1) Angstrom. Dimeric [Cu2Cl2(mu-(H2C=CHC(CH3)=CH))](2) and [Cu2Cl2(mu-(H2C=C(CH3)C(CH3)=(CH2))] units are linked by long Cu-Cl bonds leading to the formation of chains with peripheral isopropenylacetylene (2) and dimethylbutadiene (3) ligands. The crystal structure of 4 could be determined only with low precision, but can be described in terms of copper(I) chloride layers with peripheral trans-1,3-pentadiene ligands. Shifts in the infrared absorptions on coordination of the conjugated dienes (including butadiene and cis-1,3-pentadiene) to copper(I) are discussed in the light of the crystal structures of 2-4.
  •  
32.
  • Håkansson, Mikael, 1957, et al. (author)
  • Tetrameric thienylcopper and pentanuclear thienylcuprate
  • 2000
  • In: Journal of Organometallic Chemistry. - 0022-328X. ; 595:1, s. 102-108
  • Journal article (peer-reviewed)abstract
    • The reaction between 2-bromothiophene and magnesium with subsequent addition of copper(I) chloride in tetrahydrofuran followed by dioxane yields thienylcopper, [Cu-4(C4H3S)(4)] (1). Without the addition of dioxane, magnesium thienylcuprate(I), [Mg(THF)(6)][Cu-5(C4H3S)(6)](2), (2) is formed. Both copper(I) complexes are oligomeric and are bridged by the thienyl ligands solely through carbon donors, thus lacking Cu-S bonds. The former compound, 1, is tetranuclear with a square-planar copper core and Cu-Cu distances of 2.453(3) and 2.507(3) Angstrom, and 2.464(2) and 2.489(2) Angstrom within the two crystallographically independent molecules, respectively; there is a weak (CuS)-S-... interaction of 3.118(5) Angstrom between these two molecules. The anion of 2 is a closo trigonal bipyramidal cluster of copper atoms in which the (ax)-(eq) edges are bridged by the thienyl ligands. Thus the Cu(ax)-Cu(eq) distances bridged by carbon are short, 2.497(5) and 2.503(5) Angstrom, indicative of three-centre Cu-C-Cu two-electron bonds, whereas the Cu(eq)Cu-...(eq) and Cu(ax)Cu-...(ax) distances are considerably longer at 3.135(7) and 3.423(8) Angstrom, respectively. The lack of participation of sulfur in bonding within the [Cu-5(C4H3S)(6)](-) cluster is discussed.
  •  
33.
  • King, Jason D, et al. (author)
  • Synthesis and Characterization of Diphenyl-2-thienylphosphine Derivatives
  • 1999
  • In: Journal of Organometallic Chemistry. - 0022-328X. ; 573:1-2, s. 272-278
  • Journal article (peer-reviewed)abstract
    • The reaction of [Co2{μ-C2(CO2Me)2}(CO)6] with the ligand diphenyl-2-thienylphosphine, PPh2(C4H3S), yields the complexes [Co2{μ-C2(CO2Me)2}(CO)5{PPh2(C4H3S)}] (1) and [Co2{μ-C2(CO2Me)2}(CO)4{PPh2(C4H3S)}2] (2). The related complex [Co3(μ3CMe)(CO)9] reacts with the same ligand to give [Co3(μ3-CMe)(CO)8{PPh2(C4H3S)}] (3) and [Co3(μ3-CMe)(CO)7{PPh2(C4H3S))2] (4). Thermolysis of 1 at 80°C leads to partial conversion of 1 into 2, which is isolated in low yield. Similarly, thermolysis of 3 at 70°C results in partial conversion of 3 to 4. Coordination of the thienyl unit of the diphenyl-2-thienylphosphine ligand to cobalt could not be detected in these thermolyses. Complexes 1–4 have been completely characterized and the crystal structure of complex 4 has been determined.
  •  
34.
  • Kiriakidou-Kazemifar, Nitsa, et al. (author)
  • Formation of Rhodium Carbonyl Cluster Thiolates with Concomitant H2 evolution
  • 2001
  • In: Journal of Organometallic Chemistry. - 0022-328X. ; 623:1-2, s. 65-73
  • Journal article (peer-reviewed)abstract
    • Reaction of [Rh6(CO)15(NCMe)] with p-thiocresol [(4-Me)C6H4SH] leads to the formation of [Rh2(CO)4(μ-SC6H4CH3)2] as the main product along with a small amount of [Rh6(CO)16]. An approximately 30-fold excess of the thiol is required in order to obtain a good yield of the thiolate-bridged dimer while reaction of [Rh4(CO)12] with an excess of p-thiocresol leads to an apparently clean conversion to the dimeric Rh(I) complex. Mass spectrometric measurements show that the latter reaction involves evolution of H2, and CO evolution is indicated by the retardation of the reaction in CO saturated solution; these results suggest the following reaction stoichiometry: [Rh4(CO)12]+4RSH→2[Rh2(CO)4(μ-SR)2]+2H2+4CO. Kinetic measurements show that the reaction proceeds in three stages which are proposed to involve two rapid pre-equilibria and a final irreversible and relatively slow conversion to the products. The crystal and molecular structure of [Rh2(CO)4(μ2-SC6H4CH3)2] is reported.
  •  
35.
  • Kiriakidou-Kazemifar, Nitsa, et al. (author)
  • Synthesis and characterization of new thioether derivatives of [Os3(CO)12] and [H2Os3(CO)10]; crystal and molecular structures of [Os3(CO)11(L)] [Et2S, Pr2S, S(CH2)5] and [Os3(CO)9(m-H)(m-X){SMe(But)}] (X = H, OH)
  • 2001
  • In: Journal of Organometallic Chemistry. - 0022-328X. ; 623:1-2, s. 191-201
  • Journal article (peer-reviewed)abstract
    • Reaction of [Os3(CO)11(NCMe)] with R2S (R = Et, nPr) and MeSBut results in the formation of [Os3(CO)11(L)] (L = thioether) clusters in which the thioethers are coordinated in an equatorial site of the triosmium framework. Such monosubstituted clusters are also formed when [Os3(CO)10(NCMe)2] is reacted with R2S (R = Et, nPr) while reaction of the same cluster with Ph2S or MeSPh results in the formation of orthometalated clusters, viz. [Os3(m-H)(CO)10(m-h2-C6H4SR)] and [Os3(m-H)(CO)9(m3-C6H4SPh)]. The similar reaction of [Os3(m-H)2(CO)10] with Pr2S, MeSBut, MeSPh or Ph2S does not lead to discernable products except when carried out in the presence of trimethylamine N-oxide, which leads to clusters of the general formula [Os3(CO)9(m-H)2(thioether)]. The crystal and mol. structures of [Os3(CO)11(L)] (L = Et2S, Pr2S, S(CH2)5) and [Os3(CO)9(m-H)(m-X){SMe(But)}] (X = H, OH) are presented.
  •  
36.
  • Soukharev, V, et al. (author)
  • Synthesis, properties and biosensor application of cycloruthenated 2-phenylimidazoles
  • 2003
  • In: Journal of Organometallic Chemistry. - 0022-328X. ; 668:1-2, s. 75-81
  • Journal article (peer-reviewed)abstract
    • The cycloruthenation of 2-phenylimidazole (phim) by [Ru(6-C6H6)(-Cl)Cl]2 in acetonitrile in the presence of NaOH has been carried out. The unstable intermediate [Ru(phim)(MeCN)4]PF6 formed has been converted into the complexes [Ru(phim)(4,4′-Me2bpy)(MeCN)2]PF6 (2) and [Ru(phim)(LL)2]PF6 (3, LL=phen (a), bpy, 4,4′-Me2bpy), which were characterized by the mass-spectrometry, 1H-NMR spectroscopy, UV–vis spectrophotometry, and cyclic voltammetry. The RuII/III redox potentials of complexes 3 equal 130–250 mV (vs. Ag–AgCl) at pH 7 (0.01 M phosphate). Such potential range is favorable for fast exchange of electrons with the active sites of redox enzymes. In fact, the second-order rate constant for the oxidation of reduced glucose oxidase (GO) from Aspergillus niger by the electrochemically generated RuIII derivative of complex 3a equals (8.1×106 M−1 s−1). The second-order rate constant for the oxidation of 3a by the Compound II of horseradish peroxidase is 9.3×107 M−1 s−1. Complexes 3 were used as mediators for the fabrication of enzyme electrodes by simple co-adsorbing with GO or horseradish peroxidase on graphite electrodes. These electrodes were tested in flow-injection systems and showed linear responses in the range of -glucose and H2O2 concentrations 0.1–30 mM and 1–200 M, respectively. The new mediators reported herein seem promising for the construction of amperometric biosensors based on GO, horseradish peroxidase, and similar enzymes.
  •  
37.
  • Abdel-Magied, Ahmed F., et al. (author)
  • Synthesis and characterization of chiral phosphirane derivatives of [(μ-H)4Ru4(CO)12] and their application in the hydrogenation of an α,β-unsaturated carboxylic acid
  • 2017
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X. ; 849-850, s. 71-79
  • Journal article (peer-reviewed)abstract
    • Ruthenium clusters containing the chiral binaphthyl-derived mono-phosphiranes [(S)-([1,1'-binaphthalen]-2-yl)phosphirane] (S)-1a, [(R)-(2'-methoxy-1,1'-binaphthyl-2-yl)phosphirane] (R)-1b, and the diphosphirane [2,2'-di(phosphiran-1-yl)-1,1'-binaphthalene] (S)-1c have been synthesized and characterized. The clusters are [(μ-H)4Ru4(CO)11((S)-1a)] (S)-2, [(μ-H)4Ru4(CO)11((R)-1b)] (R)-3, 1,1-[(μ-H)4Ru4(CO)10((S)-1c)] (S)-4, [(μ-H)4Ru4(CO)11((S)-binaphthyl-P(s)(H)Et)] (S,S p)-5, [(μ-H)4Ru4(CO)11((S)-binaphthyl-P(R)(H)Et)] (S,R p)-6, [(μ-H)4Ru4(CO)11((R)-binaphthyl-P(s)(H)Et)] (R,S p)-7, [(μ-H)4Ru4(CO)11((R)-binaphthyl-P(R)(H)Et)] (R,R p)-8 and the phosphinidene-capped triruthenium cluster [(μ-H)2Ru3(CO)9(PEt)] 9. Clusters 5-8 are formed via hydrogenation and opening of the phosphirane ring in clusters (S)-2 and (R)-3. The phosphirane-substituted clusters were found to be able to catalyze the hydrogenation of trans-2-methyl-2-butenoic acid (tiglic acid), but no enantioselectivity could be detected. The molecular structures of (S)-4, (R,S p)-7 and 9 have been determined and are presented.
  •  
38.
  • Ahmed, SJ, et al. (author)
  • Dppm-substituted ruthenium clusters with capping sulfido and selenido ligands derived from thiourea, tetramethylthiourea and elemental selenium
  • 2006
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X. ; 691:3, s. 309-322
  • Journal article (peer-reviewed)abstract
    • Treatment of [Ru-3(CO)(10)(mu-dppm)] (4) [dppm = bis(diphenylphosphido)methane] with tetramethylthiourea at 66 degrees C gave the previously reported dihydrido triruthenium cluster [Ru-3(mu-H)(2)(mu(3)-S)(CO)(7)(mu-dppm)] (5) and the new compounds [Ru-3(mu(3)-S)(2)(CO)(7)(mu-dppm)] (6), [Ru-3(mu(3)-S)(CO)(7)(mu(3)-CO)(mu-dppm)] (7) and [Ru-3(mu 3-S)eta(I)-C(NMe2)(2)}(CO)(6)(mu(3)-CO)(mu-dppm)] (8) in 6%, 10%, 32% and 9% yields, respectively. Treatment of 4 with thiourea at the same temperature gave 5 and 7 in 30% and 10% yields, respectively. Compound 7 reacts further with tetramethylthiourea at 66 degrees C to yield 6 (30%) and a new compound [Ru-3(mu(3)-S)(2){mu(3)-C(NMe2)(2)}(CO)(6)(mu-dppm)] (9) (8%). Thermolysis of 8 in refluxing THF yields 7 in 55% yield. The reaction of 4 with selenium at 66 degrees C yields the new compounds [Ru-3(mu(3)-Se)(CO)(7)(mu(3)-CO)(mu-dppm)] (12) and [Ru-4(mu(3)-Se)(mu(3)-eta(3)-PhPCH2PPh(C6H4)(CO)(6)(mu-CO)] (11) and the known compounds [Ru-3(mu-H)(2)(mu(3)-Se)(CO)(7)(mu-dppm)] (12) and [Ru-4(mu(3)-Se)(4)(CO)(6)(mu-dppm)] (13) in 29%, 5%, 2% and 5% yields, respectively. Treatment of 10 with tetramethylthiourea at 66 degrees C gives the mixed sulfur-selenium compounds [Ru-3(mu(3)-S)([mu(3)-Se)(CO)(7)(mu-dppm)] (14) and [Ru-3(mu(3)-S)(mu(3)-Se){eta(1)-C(NMe2)(2)}(CO)(6)(mu-dppm)] (15) in 38% and 10% yields, respectively. The single-crystal XRD structures of 6, 7, 8, 10, 14 and 15 are reported.
  •  
39.
  • Akter, H, et al. (author)
  • Triphenylphosphine-substituted selenido and sulfido clusters of osmium derived from Ph3P=Se or Ph3P=S
  • 2005
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X. ; 690:21-22, s. 4628-4639
  • Journal article (peer-reviewed)abstract
    • Cleavage of P=Se bonds occurs readily in the room-temperature treatment of [Os-3(CO) (10)(MeCN)(2)] with Ph3P=Se to give three new compounds, [Os-3(mu(3)-Se)(2)(CO)(8)(PPh3)] (2), [Os-3(mu(3)-Se)( mu(3)-CO)(CO)(7)(PPh3)(2)] (5) and [Os3(mu-OH)(2)(CO)(8)(PPh3)(2)] (6), respectively, and three known compounds, [Os-3(mu(3)-Se)(2)(CO)(9)] (1), [Os-3(mu(3)-Se)(mu-CO)(2)(CO)(7)(PPh3)] (3), and 1,2-[Os-3(CO)(10)(PPh3)(2)] (4). No evidence for any product containing a co-ordinated Ph3P--Se ligand was obtained. The analogous reaction between [OS3(CO)10(MeCN)2] and Ph3P=S produces five new compounds [Os-3(mu(3)-S)(2)(CO)(8)(PPh3)] (7), [Os-3(mu(3)-S)(mu-CO)(2)(CO)(7)(PPh3)] (8), [Os-3(mu(3)-S) (mu(3)- CO)(CO)(7)(PPh3)(2)] (9), [Os-3(mu(3)-)(2)(CO)(7)(PPh3)(2)] (11) and compound 6 in addition to the known compound 4. Treatment of with Me3NO at 50 degrees C gives the trinuclear cluster [Os-3(mu(3)-Se)(2)(CO)(7)(PPh3)(NMe3)] (13) and the hexanuclear cluster [Os-6(mu(3)-Se)(4)(CO)(14) (PPh3)(2)] (12). Treatment of compound 1 with PPh3 and Me3NO at room temperature gives [Os-3(mu(3)-Se)(2)(CO)(7)(PPh3)(2)] (10). Compound 2 reacts with PPh3 similarly to give 10. Compound 3 reacts with elemental selenium at 110 degrees C to give 2. The new compounds 2, 5, 6 and 8 were characterized by single-crystal X-ray diffraction. The compounds 3, 5, 8 and 9 contain Os-3(mu(3)-S) or Os-3(mu(3)-Se)cluster cores with three metal-metal bonds while 2, 7, 10, 11 and 12 contain Os-3(mu(3)-S)(2) or Os(mu(3)-Se)(2) cores two metal-metal bonds. The two hydroxy ligands in the triosmium cluster 6 bridging the open osmium-osmium edge and are probably derived from water. A study of the dynamic exchange of PPh3 ligands in 5 is also reported.
  •  
40.
  • Begum, Noorjahan, et al. (author)
  • Reaction of [Ru-3(CO)(12)] with tri(2-furyl)phosphine: Di- and tri-substituted triruthenium and phosphido-bridged diruthenium complexes
  • 2008
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X. ; 693:8-9, s. 1645-1655
  • Journal article (peer-reviewed)abstract
    • Reaction of [Ru-3(CO)(12)] with tri(2-furyl)phosphine, P(C4H3O)(3), at 40 degrees C in the presence of a catalytic amount of Na[Ph2CO] furnishes two triruthenium complexes [Ru-3(CO)(10){P(C4H3O)(3)}(2)] (1) and [Ru-3(CO)(9){P(C4H3O)(3)}(3)] (2) with the ligand coordinated through the phosphorus atom. Treatment of 1 and 2 with Me3NO at 40 degrees C affords the dinuclear phosphido-bridged complexes [Ru-2(CO)(6)(mu-eta(1),eta(2)-C4H3O){mu-P(C4H3O)(2)}] (3) and [Ru-2(CO)(5)(mu-eta(1),eta(2)-C4H3O){mu-P(C4H3O)(2)}{P(C4H3O)(3)}] (4), respectively, that are formed via phosphorus-carbon bond cleavage of a coordinated phosphine followed by coordination of the dissociated furyl moiety to the diruthenium center in a sigma,pi-alkenyl mode. Reaction of [Ru-3(CO)(12)] with tri(2-furyl) phosphine in refluxing benzene gives, in addition to 3 and 4, low yields of the cyclometallated complex [Ru-3(CO)(9){mu-eta(1),eta(1)-P(C4H3O)(2)(C4H2O)}(2)] (5). Treatment of 3 with EPh3 (E = P, As, Sb) at room temperature yields the monosubstituted derivatives [Ru-2(CO)(5)(mu-eta(1),eta(2)-C4H3O){mu-P(C4H3O)(2)}(EPh3)] (E = P, 8; E = As, 9; E = Sb, 10). Similar reactions of 3 with P(C4H3O)(3), P(OMe)(3) and (BuNC)-N-t yield 4, [Ru-2(CO)(5)(mu-eta(1),eta(2)-C4H3O){mu-P(C4H3O)(2)}{P(OMe)(3)}] (11) and [Ru-2(CO)(5)(mu-eta(1),eta(2)-C4H3O){mu-P(C4H3O)(2)}(NCBut)] (12), respectively. The molecular structures of complexes 3, 4 and 8 have been elucidated by single crystal X-ray diffraction studies. Each complex contains a bridging sigma,pi-alkenyl group and while in 4 the phosphine is bound to the sigma-coordinated metal atom, in 8 it is at the pi-bound atom. Protonation of 3 and 4 gives the hydride complexes [(mu-H)Ru-2(CO)(6)(mu-eta(1),eta(2)-C4H3O){mu-P(C4H3O)(2)}](+) (6) and [(mu-H)Ru-2(CO)(5)(mu-eta(1),eta(2)-C4H3O){mu-P(C4H3O)(2)}{P(C4H3O)(3)}] (+) (7), respectively, while heating 3 with dimethylacetylenedicarboxylate (DMAD) in refluxing toluene gives the cyclotrimerization product, C-6(CO2Me)(6).
  •  
41.
  •  
42.
  • Bjelosevic, Haris, et al. (author)
  • Platinum(II) and gold(I) complexes based on 1,1 '-bis(diphenylphosphino)metallocene derivatives: Synthesis, characterization and biological activity of the gold complexes
  • 2012
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X. ; 720, s. 52-59
  • Journal article (peer-reviewed)abstract
    • The synthesis of series of 1,2,1' substituted bis(diphenylphosphino)- ruthenocenyl (1-4) and ferrocenyl cis-platinum(II) (5-7) and gold(I) (8-12) complexes are described. Crystal structures of 2 and 4, as well as 5, 6 and 10 confirm the molecular geometry of these ligands and their metal complexes. Preliminary investigation of four gold complexes as potential anticancer, antiHIV and antimalaria showed at least one gold compound that has excellent activity towards one of these diseases. The three gold(I) complexes, {1- [1-(dimethylamino)ethyl]-1 ,2-bis(diphenylphosphino)ruthenocene-kappa P-2,P'}bis[chlorogold(I)] (8) (IC50 = 1.40 mu M), {1-[1-(acetoxyethyl)-1',2-bis(diphenylphosphino)ferrocene-kappa P-2,P']bis[chlorogold(1)] (9) (IC50 = 0.51 mu M), {1-[1-(3-carboxypropanamido)ethyl]-1',2-bis(diphenylphosphino)-ruthenocene kappa P-2,P'} bis[chlorogold(I)] (12) (IC50 = 1.784 mu M), have the best activities against cancer, HIV and malaria respectively. (C) 2012 Elsevier B.V. All rights reserved.
  •  
43.
  • Booyens, Sharon, et al. (author)
  • Kinetic investigation of a ruthenium metathesis catalyst
  • 2007
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X. ; 692:24, s. 5508-5512
  • Journal article (peer-reviewed)abstract
    • The complex [(IMesH2)(PPh2Cy)Cl2RuCHPh] was synthesised and shown to be an active catalyst in ring-closing metathesis of a diallylmalonate. Its phosphine exchange was investigated in C6D6 using magnetisation transfer 31P NMR spectroscopy and it was found to operate via a dissociative mechanism with k353 = 4.1 ± 0.9 s−1, ΔH‡ = 84 ± 10 kJ mol−1 and ΔS‡ = 4 ± 28 J mol−1 K−1.
  •  
44.
  • Elantabli, Fatma M., et al. (author)
  • Thiophene based imino-pyridyl palladium(II) complexes : Synthesis, molecular structures and Heck coupling reactions
  • 2017
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X. ; 843, s. 40-47
  • Journal article (peer-reviewed)abstract
    • The new compounds (5-methyl-2-thiophene-2-pyridyl(R))imine [R = methyl (L1); R = ethyl (L2)] and (5-bromo-2-thiophene-2-pyridyl(R)imine [R = methyl (L3); R = ethyl (L4)] were successfully synthesized via Schiff base condensation reaction and obtained in good yields. These potential ligands were reacted with [PdCl2(COD)] and [PdClMe(COD)] to give the corresponding complexes [PdCl2(L)] (L = L1-L4; 1–4) and [PdClMe(L)] (L = L1-L4; 5–8). All compounds were characterized by IR, 1H and 13C NMR spectroscopy, elemental analysis and mass spectrometry. The molecular structures of 1, 2, 6 and 8 were confirmed by X-ray crystallography. The complexes were evaluated as catalyst precursors for standard Heck coupling reactions and showed significant catalytic activities that could be correlated with steric and electronic influences.
  •  
45.
  • Ghosh, Shishir, et al. (author)
  • Activation of tri(2-furyl)phosphine at a dirhenium centre: Formation of phosphido-bridged dirhenium complexes
  • 2009
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X. ; 694:18, s. 2941-2948
  • Journal article (peer-reviewed)abstract
    • Reaction of tri(2-furyl) phosphine (PFu(3)) with [Re-2(CO)(10) (n)(NCMe)(n)] (n = 1, 2) at 40 degrees C gave the substituted complexes [Re-2(CO)(10) (n)(PFu(3))(n)] (1 and 2), the phosphines occupying axial position in all cases. Heating [Re-2(CO)(10)] and PFu(3) in refluxing xylene also gives 1 and 2 together with four phosphido-bridged complexes; [Re-2(CO)(8) (n)(PFu(3))(n)(mu-PFu(2))(mu-H)] (n = 0, 1, 2) (3-5) and [Re-2(CO)(6)(PFu(3))(2)(mu-PFu(2))(mu-Cl)] (6) resulting from phosphorus-carbon bond cleavage. A series of separate thermolysis experiments has allowed a detailed reaction pathway to be unambiguously established. A similar reaction between [Re-2(CO)(10)] and PFu(3) in refluxing chlorobenzene furnishes four complexes which include 1, 2, 6 and the new binuclear complex [Re-2(CO)(6)(eta(1)-C4H3O)(2)(mu-PFu(2))(2)] (7). All new complexes have been characterized by a combination of spectroscopic data and single crystal X-ray diffraction studies. (C) 2009 Published by Elsevier B.V.
  •  
46.
  • Ghosh, Shishir, et al. (author)
  • Reactivity of the triruthenium ortho-metalated cluster [Ru-3(CO)(9){mu(3)- eta(1), kappa(1),kappa(2)-PhP( C6H4) CH2PPh}] with tri(2-thienyl) phosphine and tri( 2-furyl) phosphine: Formation of 1,3-diphenyl-2,3-dihydro-1H-1,3-benzodiphosphine complexes via phosphorus-carbon bond formation
  • 2009
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X. ; 694:20, s. 3312-3319
  • Journal article (peer-reviewed)abstract
    • Reaction of [Ru(CO)(9){mu(3-)eta(1),kappa(1),kappa(2)-PhP(C6H4)CH2PPh}] (1) with tri(2-thienyl) phosphine (PTh3) in refluxing THF afforded [Ru-3(CO)(9)(PTh3)(mu-dpbm)] (3){dpbm = PhP(C6H4)(CH2)PPh} and [Ru-3(CO)(6)(mu-CO)(2){mu-kappa(1),eta(1)-PTh2(C4H2S)}{mu(3)-kappa(1),ka ppa(2)-Ph2PCH2PPh}] (5) in 18% and 12% yields, respectively, while a similar reaction with tri(2-furyl)phosphine (PFu(3)) gave [Ru-3(CO)(9)(PFu(3))(mu-dpbm)] (4) and [Ru-3(CO)(7)(mu-eta(1),eta(2)-C4H3O)(mu-PFu(2)){mu(3)-eta(1),kappa(1),ka ppa(2)-PhP(C6H4)CH2PPh}] (6) in 24% and 27% yields, respectively. Compounds 2 and 4 are phosphine adducts of 1 in which the diphosphine ligand is transformed into 1,3-diphenyl-2,3-dihydro-1H-1,3-benzodiphosphine(dpbm) via phosphorus-carbon bond formation. Cluster 5 results from metalation of a thienyl ring, the cleved proton being transfoerred to the diphosphine.Carbon-phosphorus bond clevarge of a PFu(3) ligand is observed in 6 to afford a phosphido-bridge and furyl fragment, the latter bridging in a sigma,pi-vinyl fashion. The molecular strucutres of 3,5 and 6 have been determined by X-ray diffraction studies. (C) 2009 Published by Elsevier B.V.
  •  
47.
  • Ghosh, Shishir, et al. (author)
  • Unsymmetrical alkyne binding to a triruthenium centre: Oxidative-addition of diphenyl ditelluride to the furyne cluster [Ru-3(CO)(7)(mu-H)(mu(3)-eta(2)-C4H2O){mu-P(C4H3O)(2)}(mu-dppm)]
  • 2011
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X. ; 696:10, s. 1982-1989
  • Journal article (peer-reviewed)abstract
    • Oxidative-addition of PhTe2Ph to the furyne cluster [Ru-3(CO)(7)(mu-H)(mu(3)-eta(2)-C4H2O){mu-P(C4H3O)(2)}(mu-dppm)] (1) results in the isolation of four complexes; (i) the previously reported 54-electron cluster [Ru-3(CO)(6)(mu(3)-Te)(2)(mu-TePh)(2)(mu-dppm)] (5) which results from elimination of trifuryl phosphine, (ii) the furenyl cluster [Ru-3(CO)(5)(mu-eta(2)-C4H3O){mu-P(C4H3O)(2)}(mu-TePh)(2)(mu-dppm)] (6) which results from carbon-hydrogen bond formation and (iii) two new 50-electron complexes [Ru-3(CO)(5)(mu-H)(mu(3)-eta(2)-C4H2O){mu-P(C4H3O)(2)}(mu-TePh)(2)(kappa (2)-dppm)] (7) and [Ru-3(CO)(4)(mu-H){P(C4H3O)(3)}(mu(3)-eta(2)-C4H2O){mu-P(C4H3O)(2)}(mu-T ePh)(2)(kappa(2)-dppm)] (8) both containing unsymmetrical furyne ligands. The structures of all the new compounds have been unambiguously established by single crystal X-ray crystallography. Further reactivity studies have provided a clear understanding of the relative sequence of the key oxidative-addition and reductive-elimination processes, showing that 6 is an intermediate in the formation of 7. DFT calculations have been used to shed light on the unsymmetrical binding of the furyne ligand in 7 and also to show that the adopted position of the heteroatom within the furyne ring can vary within complexes of this type. (C) 2010 Elsevier B.V. All rights reserved.
  •  
48.
  • Gustafsson, Magnus, et al. (author)
  • Regioselectivity in the rhodium catalysed 1,4-hydrosilylation of isoprene. Aspects on reaction conditions and ligands
  • 2004
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X. ; 689:2, s. 438-443
  • Journal article (peer-reviewed)abstract
    • The regioselectivity in the Rh catalysed 1,4-hydrosilylation of isoprene was investigated. Variation of solvents and temperature did not significantly affect the isomer distribution between tail-product (I) and head-product (II). The choice of ligands had the greater influence, where Rh-I-based catalysts with the strong electron withdrawing ligand CO favoured production of isomer II, while Rh-I catalysts with strong electron donating ligands (for example triarylphosphines) gave isomer I as the main product. In contrast to the square planar carbonyl complex RhCl(CO)(PPh3)(2), the square planar thiocarbonyl complex RhCl(CS)(PPh3)(2), gave I as the major isomer. (C) 2003 Elsevier B.V. All rights reserved.
  •  
49.
  •  
50.
  • Hedström, Anna, 1983, et al. (author)
  • On the oxidation state of iron in iron-mediated C-C couplings
  • 2013
  • In: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X. ; 748, s. 51-55
  • Journal article (peer-reviewed)abstract
    • The nature of the active catalyst in iron-catalyzed C-C couplings has been under debate. In here, we study the couplings with aryl Grignard reagents, and clearly show that the active catalyst is an Fe(I) species. The Grignard alone can reduce the pre-catalyst to the Fe(I) state, and no further, as shown by quantification of product formation. Addition of the electrophile results in complete cross-coupling, validating the nature of the active catalyst. A computational study reveals that the active iron catalyst has a spin state of S = 3/2, high spin for Fe(I) but intermediate spin for Fe(III) complexes, even though the Fe(III) precatalyst salts have a high spin state (S = 5/2). The spin change occurs after the first transmetallation, when the strong ligand field of the aryl group raises the energy of one d-orbital, inducing an electron pairing event. All steps in the formation of an active cross-coupling catalyst are facile and strongly exergonic. (C) 2013 Elsevier B.V. All rights reserved.
  •  
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