| 1. |
- Andjelkovic, Katarina, et al.
(författare)
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Synthesis and Structural Characterization of the Co(III) Complex with 2'-[1-(2-Pyridinyl)-Ethylidene]-Oxamohydrazide (Hapsox): the Crystal Structure of Bis-{2'-[1-(2-Pyridinyl)-Ethylidene]-Oxamohydrazido} Cobalt(III) Perchlorate, [Co(apsox)2]ClO4
- 2003
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Ingår i: Journal of Coordination Chemistry. - : Informa UK Limited. - 0095-8972 .- 1029-0389. ; 56:7, s. 611-622
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Tidskriftsartikel (refereegranskat)abstract
- The synthesis of a novel ligand 2′-[1-(2-pyridinyl)-ethylidene]-oxamohydrazide (Hapsox), from a series of 2-acetylpyridine acylhydrazones, and its complex with Co(III), which is the first in this series of complexes are described. Both the ligand and the complex were characterized by elemental analysis, IR, 1H-NMR, and 13C-NMR spectra, and the structure of the complex [Co(apsox)2]ClO4 was determined by X-ray structural analysis. It was established that [Co(apsox)2]ClO4 has an octahedral geometry with two tridentate apsox ligands in monoanionic form. Structural characteristics, lengths of the bonds, and angles between the bonds were typical for Co(III) complexes of distorted octahedral geometry. Both direct and template synthesis afforded the same geometrical isomer of the complex with two apsox ligands meridionally bound to the central metal ion, even in the case when equimolar quantities of Co(ClO4)2 and Hapsox were applied.
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| 2. |
- Barreiro Fidalgo, Alexandre, et al.
(författare)
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The role of surface-bound hydroxyl radicals in the reaction between H2O2 and UO2
- 2018
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Ingår i: Journal of coordination chemistry (Print). - : Informa UK Limited. - 0095-8972 .- 1029-0389. ; 71:11-13, s. 1799-1807
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Tidskriftsartikel (refereegranskat)abstract
- In this work, we have studied the reaction between H2O2 and UO2 with particular focus on the nature of the hydroxyl radical formed as an intermediate. Experiments were performed to study the kinetics of H2O2 consumption and uranium dissolution at different initial H2O2 concentrations. The results show that the consumption rates at a given H2O2 concentration are different depending on the initial H2O2 concentration. This is attributed to an alteration of the reactive interface, likely caused by blocking of surface sites by oxidized U/surface-bound hydroxyl radicals. The dissolution yield given by the amount of dissolved uranium divided by the amount of consumed hydrogen peroxide was used to compare the different cases. For all initial H2O2 concentrations, the dissolution yield increases with reaction time. The final dissolution yield decreases with increasing initial H2O2 concentration. This is expected from the mechanism of catalytic decomposition of H2O2 on oxide surfaces. As the experiments were performed in solutions containing 10mM H2O2 and a strong concentration dependence was observed in the 0.2-2.0mM H2O2 concentration range, we conclude that the intermediate hydroxyl radical is surface bound rather than free.
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| 3. |
- Chen, Y. G., et al.
(författare)
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Synthesis of chiral salen Mn(III) complexes covalently linked to Re(I)-based photosensitizers
- 2006
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Ingår i: Journal of coordination chemistry (Print). - : Informa UK Limited. - 0095-8972 .- 1029-0389. ; 59:5, s. 475-484
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Tidskriftsartikel (refereegranskat)abstract
- Two Mn(III)Re(I) binuclear complexes were prepared as catalyst-photosensitizer models, in which the chiral pyrrolidine salen Mn(III) unit was covalently bonded to an Re(I) bipyridyl carbonyl moiety via a carboxamide linkage. The spectral and electrochemical properties of the Mn(III)Re(I) complexes were studied.
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| 4. |
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| 5. |
- Ellis, W. Chadwick, et al.
(författare)
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Bis phenylene flattened 13-membered tetraamide macrocyclic ligand (TAML) for square planar cobalt(III)
- 2018
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Ingår i: Journal of coordination chemistry (Print). - : TAYLOR & FRANCIS LTD. - 0095-8972 .- 1029-0389. ; 71:11-13, s. 1822-1836
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Tidskriftsartikel (refereegranskat)abstract
- The preparation, characterization, and evaluation of a cobalt(III) complex [CO{(OC)2(o,o'-NC6H4NCO)2CMe2}(OH2)]- with 13-membered tetraamide macrocyclic ligand (TAML) is described. This is a square-planar (X-ray) S=1 paramagnetic (H-1 NMR) compound, which becomes an S=0 diamagnetic octahedral species in excess d(5)-pyridine. Its one-electron oxidation at an electrode is fully reversible with the lowest E-1/2 value (0.66V vs SCE) among all investigated Co-III TAML complexes. The oxidation results in a neutral blue species which is consistent with a Co-III/radical-cation ligand. The ease of oxidation is likely due to the two benzene rings incorporated in the ligand structure (whereas there is just one in many other Co-III TAMLs). The oxidized neutral species are unexpectedly EPR silent, presumably due to the -stacking aggregation. However, they display eight-line hyperfine patterns in the presence of excess of 4-tert-butylpyridine or 4-tert-butyl isonitrile. The EPR spectra are more consistent with the Co-III/radical-cation ligand formulation rather than with a Co-IV complex. Attempts to synthesize a similar vanadium complex under the same conditions as for cobalt using [(VO)-O-V(OCHMe2)(3)] were not successful. TAML-free decavanadate was isolated instead. [GRAPHICS] .
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| 6. |
- Jana, Subrata, et al.
(författare)
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Variation in crystalline architectures through supramolecular interactions in copper(II) complexes with tridentate N2O donor Schiff bases
- 2015
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Ingår i: Journal of Coordination Chemistry. - : Informa UK Limited. - 1026-7441 .- 0095-8972 .- 1029-0389. ; 68:14, s. 2520-2538
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Tidskriftsartikel (refereegranskat)abstract
- Three copper(II) complexes, [Cu(L-1)(H2O)(ClO4)]0.5H(2)O (1), [Cu(L-2)(H2O)(ClO4)]0.5H(2)O (2), and [Cu(L-2)(NCNC(OCH3)NH2)]ClO4 (3), where HL1=4-bromo-2-(-(quinolin-8-ylimino)methyl)phenol and HL2=1-(-(quinolin-8-ylimino)methyl)naphthalen-2-ol, have been prepared and characterized by elemental analysis, IR, UV-vis and fluorescence spectroscopy and single-crystal X-ray diffraction studies. The copper(II) centers assume five-coordinate square-pyramidal geometries in 1 and 2, whereas square planar copper(II) is present in 3. A methanol molecule has been inserted in the pendant end of the ligated dicyanamide in 3. Various supramolecular architectures are formed by hydrogen bonding, , C-H, and lp interactions.
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| 7. |
- Karnahl, Michael, et al.
(författare)
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Structural and spectroscopic characterization of tetranuclear iron complexes containing a (P2N2Ph)-N-R bridge
- 2012
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Ingår i: Journal of coordination chemistry (Print). - : Informa UK Limited. - 0095-8972 .- 1029-0389 .- 1026-7441. ; 65:15, s. 2713-2723
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Tidskriftsartikel (refereegranskat)abstract
- A pair of tetranuclear iron complexes consisting of two Fe-2(Cl(2)bdt)(CO)(5) subunits (Cl(2)bdt = 3,6-dicholorobenzene-1,2-dithiolate) bridged by different cyclic 1,5-diaza-3,7-diphosphacyclooctane (P2N2) ligands were prepared and structurally characterized. In the solid state, the P2N2 ligands adopt a boat conformation, which results in rather short distances between the two Fe-2(Cl(2)bdt)(CO)(5) clusters that promotes electronic communication across the diphosphine ligand.
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| 8. |
- Kelley, Steven P., et al.
(författare)
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Structural analysis of mono-substituted N-butyl-pyridinium salts : in search of ionic liquids
- 2021
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Ingår i: Journal of coordination chemistry (Print). - : Informa UK Limited. - 0095-8972 .- 1029-0389. ; 74:1-3, s. 117-128
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Tidskriftsartikel (refereegranskat)abstract
- Four mono-substituted N-butylpyridinium salts, 1-butyl-4-dimethylaminopyridinium chloride [b4dmapy]Cl, 1-butyl-4-methylpyridinium bromide [b4mpy]Br, 1-butyl-4-methylpyridinium hexafluorophosphate [b4mpy][PF6], and 1-butyl-3-methylpyridinium hexafluorophosphate [b3mpy][PF6] were synthesized and characterized using single crystal X-ray diffraction. The crystal structures were examined with the intent of identifying ion interactions leading to higher melting points of the halide salts with respect to the [PF6]– salts. The changes in hydrogen bonding, C–H⋅⋅⋅π, and van der Waals interactions have been analyzed with respect to anion, functional groups, and the symmetry of the cation to establish interdependence with the compound’s physicochemical properties. It has been observed that the cation–anion interactions are represented by highly directional hydrogen bonds and show strong preference to positions of interaction depending on the anion. The cations of the halide salts show strong tendency towards higher dimensional formations, while those of the [PF6]– salts prefer low dimensional assemblies both being based mainly on the weaker van der Waals interactions. These interactions depend on the shape of the cation but may offer certain structure-ordering rigidity accommodating variable anions.
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| 9. |
- Kessler, Vadim
(författare)
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A family of hexanuclear Mn(III) single-molecule magnets
- 2014
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Ingår i: Journal of Coordination Chemistry. - : Informa UK Limited. - 0095-8972 .- 1026-7441 .- 1029-0389. ; 67, s. 3972–3986-
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Tidskriftsartikel (refereegranskat)abstract
- In an attempt to employ salicylic acid (HOsalH), 2,6-dihydroxy benzoic acid {(HO) naphthalene-1,8-dicarboxylic acid {1,8-naph(CO means to alter the structural identity of the hexanucluear clusters usually obtained from this reaction system, we have isolated a family of hexanuclear Mn(III) complexes based on salicyladloxime (saoH 2-hydroxy-1-naphthaldehyde oxime (naphthsaoH2PhCO2H}, and2H)2} in Mn(III) salicylaldoximate chemistry as a2) and2). Five hexanuclear clusters, [Mn6O2(sao)6(HOsal) 2 ((EtOH)4]·EtOH (1·EtOH), [Mn6O2(sao)6{1,8-naph(CO2Me)(CO2)}2(MeOH)6]·3MeOH2·3MeOH), [Mn6O2(naphthsao)6{1,8-naph(CO2Et)(CO2)}2(EtOH)6] (3·2MeOH), [Mn6O2(naphthsao) 6 ( properties of(MeCO2)2(EtOH)4]·2H2O (4·2H2O), and [Mn6O2(naphthsao)6{(HO)2PhCO2}2(EtOH)4]·4EtOH5·4EtOH), have been synthesized and characterized by single-crystal X-ray crystallography. The magnetic3, 4, and 5 are discussed.
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| 10. |
- Kessler, Vadim
(författare)
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Group III quinaldates: synthesis, structure and photoluminescence
- 2017
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Ingår i: Journal of Coordination Chemistry. - : Informa UK Limited. - 0095-8972 .- 1026-7441 .- 1029-0389. ; 70, s. 997-1007
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Tidskriftsartikel (refereegranskat)abstract
- The reactions of Al(III), Ga(III) and In(III) nitrates with 2-quinaldic acid (qaH) afforded [Al-2(OH)(2)(qa)(4)]center dot 2H(2)O (1), [Ga(qa)(2)(H2O)(2)]NO3 (2) and [In(qa)(2)(NO3)(H2O)] (3), respectively, in high yields. The crystal structures of 1, 2 and 3 have been determined by single-crystal X-ray crystallography. The structure of 1 features a di-hydroxo bridged [Al-2(mu-OH)(2)](4+) dimer in which each Al(III) is further ligated by two bidentate chelate qa(-) ligands. Complexes 2 and 3 are mononuclear with the M(III) ions in octahedral environments surrounded by two bidentate chelate qa(-) and two H2O in 2 or one H2O and a terminal NO3- in 3. Characteristic IR as well as thermal analysis and solid-state fluorescence are discussed.[GRAPHICS].
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| 11. |
- Lennartsson, Anders, 1980, et al.
(författare)
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Bridging nitrile groups in a metal-organic framework
- 2012
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Ingår i: Journal of Coordination Chemistry. - : Informa UK Limited. - 0095-8972 .- 1029-0389. ; 65:23, s. 4194-4202
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Tidskriftsartikel (refereegranskat)abstract
- This article describes two coordination polymers based on sodium and nickel triflates, respectively, and the linker adiponitrile (1,4-butanedinitrile). Sodium triflate forms a coordination network with adiponitrile, where the nitriles bridge the sodium ions, a rare coordination mode for a nitrile. Crystal structures of alkali metal complexes of linear aliphatic dinitriles have not been reported previously. With nickel triflate, a cationic 1-D coordination polymer results upon coordination of adiponitrile.
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| 12. |
- Massoud, Al-Shimaà A A, 1980, et al.
(författare)
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Two 2-D copper(II) azido compounds: catena-poly[di-μ1,1- azido,di-μN,O-(quinolinecarboxylato)(aqua)copper(II)] and 1-D catena-poly[di-μN,N'-(quinoxaline)copper(II)nitrate]
- 2009
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Ingår i: Journal of Coordination Chemistry. - : Informa UK Limited. - 0095-8972 .- 1029-0389. ; 62:4, s. 519-530
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Tidskriftsartikel (refereegranskat)abstract
- We synthesized three copper(II) complexes with two structurally related polydentate ligands,quinoline-4-carboxylic acid (quCOOH) and quinoxaline (qux). The structures of these complexes were determined using X-ray single crystal crystallography. Complex 1,[Cu(quCOO)(N3)(H2O)]n, has a 2-D polymeric structure through di-μ1,1 azido groups forming (Cu2N2) dimeric units and di-μN,O quinoline carboxylate bridging the binuclear copper units.[Cu(quCOO)(N3)(H2O)]n . 0.87MeOH, (2), has the same structure as 1 in addition to MeOH molecules separating the 2-D sheets of [Cu(quCOO)(N3)(H2O)]n. [Cu(qux)(NO3)2]n, (3), has nocoordinated azido groups, but the quinoxaline is a bidentate bridging ligand giving a 1-D chain,while the μO,O' chelating nitrato groups stabilize the chain structure by forming a square planarcoordination sphere around copper. IR and UV–Vis spectra of the complexes are in agreementwith the crystal structures.
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| 13. |
- Rusanova, Daniela, et al.
(författare)
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Copper(I) O,O '-dialkyldithiophosphate clusters : EXAFS, NMR and X-ray diffraction studies
- 2007
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Ingår i: Journal of coordination chemistry (Print). - : Informa UK Limited. - 0095-8972 .- 1029-0389. ; 60:5, s. 517-525
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Tidskriftsartikel (refereegranskat)abstract
- Copper K- edge EXAFS data for six polycrystalline cubic cluster compounds, {Cu-8[ S2P(OR)(2)](6)(mu(8)- S)} with R= Et, Pr-n, Pr-i, Bu-n, Bu-i and Am-i, show that the architecture of their Cu-8(S2P)(2)S cores is fairly rigid and independent of both length and branching of the alkyl chain, and that the structure of the cluster is maintained in acetone solution. Solid- state P-31 CP-MAS and static Cu-65 NMR data for {Cu-8[S2P(O-n Pr)(2)] 6(mu(8)- S)} and {Cu-8[S2P(OEt)(2)](6) mu(8)- S)} show similarities in the icosahedral O,O'- dialkyldithiophosphate shells and in the `cubic' copper cores in these cluster compounds. The crystal structure of {Cu-8[S2P(O-n Pr)(2)](6) (mu(8)- S)} was resolved using single- crystal X- ray diffraction.
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| 14. |
- Shi, W, et al.
(författare)
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Synthesis and characterization of a six-coordinate monomeric Mn(III) complex with SOD-like activity
- 2006
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Ingår i: Journal of Coordination Chemistry. - : Informa UK Limited. - 1026-7441 .- 0095-8972 .- 1029-0389. ; 59:2, s. 119-130
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Tidskriftsartikel (refereegranskat)abstract
- The complex [Mn-III(HL)(L)(py)(CH3OH)](CH3OH)-C-. (H2L=2-ortho-hydroxyphenylbenzimidazole, py pyridine), 1, has been characterized spectroscopically and by X-ray crystallography. The complex is triclinic, space group P-1(-) with a = 10.396(2), b = 10.7340(10), c = 15.193(2) angstrom, alpha = 73.193(4)degrees, beta = 76.283(8)degrees, gamma = 61.400(40)degrees, V = 1415.1(4)angstrom(3), Z = 2, D-c = 1.445 Mg m(-3), M-r = 615.56, mu = 0.515 mm(-1), F(000) = 640, R = 0.0631, wR = 0.1525. Manganese is six-coordinate in an N3O3 ligand sphere created by two bidentate H2L ligands and solvent molecules with a slightly distorted, axially elongated octahedral geometry. Electronic absorption spectra show pi-pi* and Ligand Metal Charge Transfer (LMCT) transitions in the UV region and d-d transitions in the visible region. Solvent molecules coordinated to the Mn(III) ion in the crystal are thought to retain their coordination in solution. It is shown that 1 has reaction activity with the superoxide ion, as indicated by inhibition of pyrogallol autoxidation and by spin trapping electron paramagnetic resonance (EPR) spectroscopy. The N3O3 ligand set in 1 is similar to that in native MnSOD (superoxide dismutatase) in the substrate-bound state. The correlation between the ligand set in 1 and its reaction with the superoxide ion is discussed.
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| 15. |
- Smékal, Zdenek, et al.
(författare)
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Synthesis and Characterization of Binuclear (μ-Oxalato) Copper(II) Complexes with N,N'-Diethylethylenediamine or N,N,N'-Trimethylethylenediamine
- 2002
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Ingår i: Journal of Coordination Chemistry. - : Informa UK Limited. - 0095-8972 .- 1029-0389. ; 55:5, s. 595-608
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Tidskriftsartikel (refereegranskat)abstract
- Three new binuclear μ-oxalato copper(II) complexes of composition [(Cu(N,N'-dieten) H2O2ox](ClO4)2·H2O (1) (N,N'-dieten = N,N'-diethylethylenediamine, H2ox = oxalic acid), [(Cu(trimeen)H2O)2ox](ClO4)2·2H2O (2) (trimeen = N,N,N'-trimethylethylenediamine) and [(Cu(trimeen)H2O)2ox](NO3)2·2H2O (3) have been isolated from the reactions of Cu(ClO4)2·6H2O (or Cu(NO3)2·3H2O), the appropriate amine and Na2ox in water and have been characterized by IR and electronic spectroscopy and magnetic measurements. The crystal structure of [(Cu(N,N'-dieten)H2O)2ox](ClO4)2.H2O (1) has been determined by single-crystal X-ray analysis. The structure of (1) consists of binuclear cations [(N,N'-dieten)H2O)Cu(ox)Cu(N,N'-dieten)H2O)]2+, perchlorate anions and water molecules of crystallization. The copper atom is coordinated by two oxygen atoms of the oxalato ligand, two nitrogen atoms belonging to N,N'-dieten and one oxygen atom of water in a distorted square-pyramidal arrangement. The temperature dependence of magnetic susceptibilities (78-293K) was measured for 1-3. Magnetochemical measurements show that copper(II) ions in these compounds are antiferromagnetically coupled with J = -172 cm-1, -172 cm-1 and -168 cm-1 (H = -2JS1S2, S1 = S2 = 1/2) for 1, 2 and 3, respectively.
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| 16. |
- Wojciechowska, Agnieszka, et al.
(författare)
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Isothiocyanate controlled architecture, spectroscopic, and magnetic behavior of copper(II) l-arginine complexes
- 2019
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Ingår i: Journal of coordination chemistry (Print). - : Taylor & Francis. - 0095-8972 .- 1029-0389. ; 72:8, s. 1358-1377
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Tidskriftsartikel (refereegranskat)abstract
- We synthesized an l-arginine complex with the formula [Cu(l-Arg)(2)(NCS)](NCS)H2O (1) (l-Arg = l-arginine). Two cis-chelated l-arginine zwitterions form the basal plane, while the weakly N-bonded isothiocyanate is located at the apex of the distorted square pyramidal structure (=0.143). The non-coordinated NCS- anions held layers together in a 3-D supramolecular network. The crystal structure, spectroscopic (FT-IR, Raman, NIR-Vis-UV, EPR) and magnetic properties of 1 have been compared with [Cu(l-Arg)(NCS)(2)] (2). For 1, two absorptions are observed for (C=N) stretching vibrations, corresponding to NCS- ions N-bonded to the central Cu(II) (2077cm(-1)) and in the lattice (2057cm(-1)). In 2 a single band is observed at 2102cm(-1), indicating equivalent NCS- ions in the structure. The EPR spectra of complexes show anisotropic signal with g(perpendicular to) and g(||) 2.062, 2.235 (1), and 2.08, 2.225 (2) characteristic for cis-N2O2 and N3O donor sets in the xy plane, respectively. The unpaired electron mainly occupies the d(x2-y2) orbital, also confirmed by the single envelope of d-d bands at ca. 16,000cm(-1) for 1 and 16,500cm(-1) for 2. The magnetic properties ofcompounds are characteristic of a very weak antiferromagnetic interaction with J=-0.055cm(-1) and J=-0.096cm(-1) for 1 and 2, respectively.
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| 17. |
- Zahoor, A., et al.
(författare)
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Zn(II) carboxylates containing heterocyclic secondary ligands : synthesis and structure manifestation through DFT studies
- 2021
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Ingår i: Journal of coordination chemistry (Print). - : Taylor and Francis Ltd.. - 0095-8972 .- 1029-0389. ; 74:12, s. 1978-1991
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Tidskriftsartikel (refereegranskat)abstract
- New Zn(II) complexes (1–8) of general formula [Zn(R)2(L')2], where R = cinnamic acid (1–7), L' = 3-pyridine carboxamide (1), 2,2'-bipyridine (2), 3-pyridinecarbonitrile (3), 2-amino-5-(4-pyridinyl)-1,3,4-thiadiazole (4), 2-methylimidazole (5), 2-phenylimidazole (6), 2-imidazolidinethione (7) and for (8), R = acetic acid; L' = 2-amino-5-(4-pyridinyl)-1,3,4-thiadiazole)2, have been synthesized by a stoichiometric reaction between Zn(II) carboxylate(s) and the respective nitrogen-based ligands. The prepared compounds are analyzed by FTIR, NMR spectroscopy and single crystal X-ray diffraction techniques for their structural manifestations along with elemental analyses. The crystallographic data for 6 and 8 exhibit four-coordinated zinc having distorted tetrahedral molecular geometry. The thermogravimetric data demonstrate high stability of the compounds with gradual loss of acetate and thiadiazol fragments that ultimately lead to zinc oxide as the residual mass of 8. Quantum chemical calculations indicate that 7 is the softest in reactivity having the lowest band gap as determined from the energies of frontier molecular orbitals whereas 8 is highly polar with the highest dipole moment value of 12.61 D. The computational data are a complement to the success of the research.
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