| 1. |
- Begum, Noorjahan, et al.
(författare)
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Reaction of [Ru-3(CO)(12)] with tri(2-furyl)phosphine: Di- and tri-substituted triruthenium and phosphido-bridged diruthenium complexes
- 2008
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Ingår i: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X. ; 693:8-9, s. 1645-1655
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Tidskriftsartikel (refereegranskat)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).
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| 2. |
- Rahman, Mohammad A., et al.
(författare)
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Reaction of tri(2-furyl)phosphine with triosmium clusters: C-H and P-C activation to afford furyne and phosphinidene ligands
- 2011
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Ingår i: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X. ; 696:2, s. 607-612
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Tidskriftsartikel (refereegranskat)abstract
- Addition of tri(2-furyl)phosphine. PFu(3), to [Os-3(CO)(10)(mu-H)(2)] at room temperature gives [HOs3(CO)(10)(PFu(3)) (mu-H)] (1), while in refluxing toluene the same reactants afford [Os-3(CO)(9)(mu(3)-PFu(2)(C4H2O))(mu-H)] (2) resulting from orthometallatation of a furyl ring. Reaction of PFu(3) with [Os-3(CO)(10-n)(NCMe)n] (n = 0, 1, 2) affords the substituted clusters [Os-3(CO)(12-n)(PFu(3))(n)] (n = 1-3) (3-5), the phosphine ligands occupying equatorial position in all cases. Heating [Os-3(CO)(11)(PFu(3))] (3) in refluxing octane gives [Os-3(CO)(9)(mu(3)-PFu)(mu(3)-eta(2)-C4H2O)] (6) which results from both carbon-hydrogen and carbon-phosphorus bond activation and contains both mu(3)-eta(2)-furyne and furylphosphinidene ligands. All new clusters have been characterized by spectroscopic methods together with single crystal X-ray diffraction for 2,3 and 6. (c) 2010 Published by Elsevier B.V.
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| 3. |
- Deeming, Antony J, et al.
(författare)
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Oxidative addition of silanes R3SiH to the unsaturated cluster [Os3(µ-H){µ3-Ph2PCH2PPh(C6H4)}(CO)8]: Evidence for reversible silane formation in the dynamic behaviour of [Os3(µ-H)(SiR3)(CO)9(µ-dppm)]
- 2004
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Ingår i: Dalton Transactions. - 1477-9234. ; 2004:21, s. 3709-3714
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Tidskriftsartikel (refereegranskat)abstract
- Oxidative addition of the silanes R3SiH (R3= Ph3, Et3, EtMe2) to the unsaturated cluster [Os3(µ-H){µ3-Ph2PCH2PPh(C6H4)}(CO)8] leads to the saturated clusters [Os3(µ-H)(SiR3)(CO)9(µ-dppm)](SiR3= SiPh31, SiEt32 and SiEtMe23) and the unsaturated clusters [Os3(µ-H)2(SiR3){µ3-Ph2PCH2PPh(C6H4)}(CO)7](SiR3= SiPh34, SiEt35 and SiEtMe26). Structures are based on spectroscopic evidence and a XRD structure of [Os3(µ-H)(SiPh3)(CO)9(µ-dppm)]1 in which all non-CO ligands are coordinated equatorially and the hydride and the silyl groups are mutually cis. From variable-temperature 1H NMR spectra of the SiEt3 compound 2, exchange of the P nuclei is clearly apparent. Simultaneous migrations of the SiEt3 group and of the hydride from one Os–Os edge to another generate a time-averaged mirror plane in the molecule. VT 1H NMR spectra of the somewhat less bulky compound [Os3(µ-H)(SiMe2Et)(CO)9(µ-dppm)]3 have been analysed. Two isomers 3a and 3b are observed with the hydride ligand located on different Os–Os edges. Synchronous migration of the hydride and SiMe2Et groups is faster than the observed interconversion of isomers which occurs by hydride migration alone. The synchronous motion of H and SiR3only occurs when these ligands are mutually cis as in the major isomer 3a and we propose that this process requires the formation of a transient silane complex of the type [Os3(2-HSiR3)(CO)9(µ-dppm)]. Turnstile rotation within an Os(CO)3(2-HSiR3) group leads to the observed exchange within the major isomer 3a without exchange with the minor isomer. This process is not observed for the minor isomer 3b because the hydride and the silyl group are mutually trans. Protonation to give [Os3(µ-H)2(SiR3)(CO)9(µ-dppm)]+ totally suppresses the dynamic behaviour because there are no edge vacancies.
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| 4. |
- Ghosh, Shishir, et al.
(författare)
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Carbon-hydrogen bond activation of phenyldi(2-thienyl)phosphine at a triosmium cluster centre
- 2010
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Ingår i: Inorganica Chimica Acta. - : Elsevier BV. - 0020-1693. ; 363:7, s. 1611-1614
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Tidskriftsartikel (refereegranskat)abstract
- The phenyldi(2-thienyl)phosphine (PhPTh2) complexes [Os-3(CO)(12-n)(PhPTh2)(n)] (n = 1-3) (1-3) have been prepared. Thermolysis of 1 and either 2 or 3 in octane affords carbon-hydrogen bond activation products [Os-3(CO)(9){mu(3)-PPhTh(C4H2S)}(mu-H)] (4) and [Os-3(CO)(8)(PPhTh2){mu(3)-PPhTh(C4H2S)}(mu-H)] (5), respectively. Both exist as isomeric mixtures differing in the relative positions of phenyl and thienyl substituents with respect to the triosmium centre. The nature of the process has been confirmed by a single crystal X-ray diffraction analysis of 4. (C) 2010 Elsevier B.V. All rights reserved.
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| 5. |
- Ghosh, Shishir, et al.
(författare)
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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
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Ingår i: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X. ; 694:20, s. 3312-3319
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Tidskriftsartikel (refereegranskat)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.
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| 6. |
- Ghosh, Shishir, et al.
(författare)
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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
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Ingår i: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X. ; 696:10, s. 1982-1989
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Tidskriftsartikel (refereegranskat)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.
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| 7. |
- Hizbullah, Lintang, et al.
(författare)
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Synthesis of phosphine derivatives of [Fe2(CO)6(μ-sdt)] (sdt = SCH2SCH2S) and investigation of their proton reduction capabilities
- 2023
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Ingår i: Journal of Inorganic Biochemistry. - 0162-0134. ; 246
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Tidskriftsartikel (refereegranskat)abstract
- The reactions of [Fe2(CO)6(μ-sdt)] (1) (sdt = SCH2SCH2S) with phosphine ligands have been investigated. Treatment of 1 with dppm (bis(diphenylphosphino)methane) or dcpm (bis(dicyclohexylphosphino)methane) affords the diphosphine-bridged products [Fe2(CO)4(μ-sdt)(μ-dppm)] (2) and [Fe2(CO)4(μ-sdt)(μ-dcpm)] (3), respectively. The complex [Fe2(CO)4(μ-sdt)(κ2-dppv)] (4) with a chelating diphosphine was obtained by reacting 1 with dppv (cis-1,2-bis(diphenylphosphino)ethene). Reaction of 1 with dppe (1,2-bis(diphenylphosphino)ethane) produces [{Fe2(CO)4(μ-sdt)}2(μ-κ1-dppe)] (5) in which the diphosphine forms an intermolecular bridge between two diiron cluster fragments. Three products were obtained when dppf (1,1′-bis(diphenylphosphino)ferrocene) was introduced to complex 1; they were [Fe2(CO)5(μ-sdt)(κ1-dppfO)] (6), the previously known [{Fe2(CO)5(μ-sdt)}2(μ-κ1-κ1-dppf)] (7), and [Fe2(CO)4(μ-sdt)(μ-dppf)] (8), with complex 8 being produced in highest yield. Single crystal X-ray diffraction analysis was performed on compounds 2, 3 and 8. All structures reveal the adoption of an anti-arrangement of the dithiolate bridges, while the diphosphines occupy dibasal positions. Infra-red spectroscopy indicates that the mono-substituted complexes 5, 6, and 7 are inert to protonation by HBF4.Et2O, but complexes 2, 3, 4 and [Fe2(CO)5(μ-sdt)(κ1-PPh3)] (9) show shifts of their ν(C-O) resonances that indicate that protons bind to the metal cores of the clusters. Addition of the one-electron oxidant [Cp2Fe]PF6 does not lead to any discernable shift in the IR resonances. The redox chemistry of the complexes was investigated by cyclic voltammetry, and the abilities of complexes to catalyze electrochemical proton reduction were examined.
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| 8. |
- Raha, Arun K., et al.
(författare)
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A comparative study of the reactivity of the lightly stabilized cluster [Os-3(CO)(8){mu(3)-Ph2PCH2P(Ph)C6H4}(mu-H)] towards tri(2-thienyl)-, tri(2-furyl)- and triphenyl-phosphine
- 2014
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Ingår i: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X. ; 751, s. 399-411
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Tidskriftsartikel (refereegranskat)abstract
- Reactions of the lightly stabilized triosmium cluster [Os-3(CO)(8){mu(3)-Ph2PCH2P(Ph)C6H4}(mu-H)] with tri(2-thienyl)phosphine (PTh3) and tri(2-furyl)phosphine (PFu(3)) are described and compared to analogous reactions with PPh3. At room temperature, a number of products are isolated: [Os-3(CO)(10)(mu-dppm)] from CO addition, [Os-3(CO)(8)(PR3){mu(3)-Ph2PCH2P(Ph)C6H4}(mu-H)] from phosphine addition, [Os-3(CO)(9)(PR3)(mu-dppm)] from phosphine and CO addition and [Os-3(CO)(8)(PR3)(2)(mu-dppm)] from addition of two equivalents of phosphine. The latter are shown by NMR and X-ray diffraction to exist as 1,2-isomers, whereby one phosphine is bound to the non-dppm-substituted center and the second shares an osmium atom with one end of the diphosphine. Heating 1,2-[Os-3(CO)(8)(PTh3)(2)(mu-dppm)] at 100 degrees C results in its clean isomerization to the 1,1-isomer in which both monodentate phosphines are located on the same osmium atom. Prolonged heating of [Os-3(CO)(8)(PR3)(2)(mu-dppm)] (R = Th, Ph) at 110 degrees C gives [Os-3(CO)(9)(PR3)(mu-dppm)] and the new lightly stabilized clusters [Os-3(CO)(7)(PR3){mu(3)-Ph2PCH2P(Ph)C6H4}(mu-H)], the latter being formed by loss of phosphine and CO with concurrent metalation of a phenyl ring. Heating [Os-3(CO)(8)(PFu(3))(2)(mu-dppm)] at 110 degrees C gives [Os-3(CO)(9)(PFu(3))(mu-dppm)] together with the carbon-phosphorus bond cleavage products [Os-3(CO)(7)(mu-PFu(2))(mu(3)-eta(2)-C4H2O)(mu-H)(mu-dppm)] and [Os-3(CO)(7)(mu-PFu(2))(mu(3)-eta(2)-C6H3CH3)(mu-H)(mu-dppm)]. All new compounds were characterized by analytical and spectroscopic techniques together with single crystal X-ray diffraction analysis of nine clusters. Density functional theory (DFT) calculations have been carried out on isomers of [Os-3(CO)(8)(PR3)(2)(mu-dppm)] in order to understand the observed isomer ratios. (C) 2013 Elsevier B.V. All rights reserved.
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| 9. |
- Rahaman, Ahibur, et al.
(författare)
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Phosphine addition to the sigma,pi-thienyl complex [Fe-2(CO)(6)(mu-Th)(mu-PTh2)] (Th = C4H3S): Carbonyl substitution and migratory carbonyl insertion to give the thienyl-acyl complexes [Fe-2(CO)(4)(diphosphine)(mu-O=C-Th)(mu-PTh2)]
- 2015
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Ingår i: Inorganica Chimica Acta. - : Elsevier BV. - 0020-1693. ; 430, s. 208-215
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Tidskriftsartikel (refereegranskat)abstract
- The reactivity of the sigma,pi-thienyl complex [Fe-2(CO)(6)(mu-Th)(mu-PTh2)] (1) towards a range of phosphines has been studied. With PR3 (R = Ph, Th) carbonyl substitution affords [Fe-2(CO)(5)(PR3)(mu-Th)(mu-PTh2)] (2ab) as the major product, with smaller amounts of the thienylacyl complexes [Fe-2(CO)(5)(PR3)(mu-O=C-Th)(mu-PTh2)] (3ab) resulting from a migratory carbonyl insertion into the thienyl ligand. With diphosphines, thienylacyl complexes are the major products in all cases. With dppm, [Fe-2(CO)(4)(mu-dppm)(mu-O=C-Th)(mu-PTh2)] (4) results in which the diphosphine bridges the ironiron bond, while with other diphosphines the chelate complexes [Fe-2(CO)(4)(kappa(2)-diphosphine)(mu-O=C-Th)(mu-PTh2)] (59) are isolated, as established through crystallographic studies on [Fe-2(CO)(4)(kappa(2)-dppe)(mu-O=C-Th)(mu-PTh2)] (5) and [Fe-2(CO)(4)(kappa(2)-dppb)(mu-O=C-Th)(mu-PTh2)] (9), both of which show that the diphosphine binds selectively to the oxygen-bound metal centre with phosphorus atoms lying trans to the metalmetal bond and mu-PTh2 bridge. With 1,2-bis(diphenylphosphino)benzene (dppb), [Fe-2(CO)(5){mu,kappa(2)-C6H4PPh(C6H4)PPh2}(mu-PTh2)] (10) is isolated in low yields and results from cyclometalation of a phenyl ring and putative elimination of thiophene. In a separate experiment, it has been shown that heating 9 results in the slow formation of 10. (C) 2015 Elsevier B.V. All rights reserved.
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| 10. |
- Rahaman, Ahibur, et al.
(författare)
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Proton reduction by phosphinidene-capped triiron clusters
- 2021
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Ingår i: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X. ; 943
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Tidskriftsartikel (refereegranskat)abstract
- Bis(phosphinidene)-capped triiron carbonyl clusters, including electron rich derivatives formed by substitution with chelating diphosphines, have been prepared and examined as proton reduction catalysts. Treatment of the known cluster [Fe3(CO)9(µ3-PPh)2] (1) with various diphosphines in refluxing THF (for 5, refluxing toluene) afforded the new clusters [Fe3(CO)7(µ3-PPh)2(κ2-dppb)] (2), [Fe3(CO)7(µ3-PPh)2(κ2-dppv)] (3), [Fe3(CO)7(µ3-PPh)2(κ2-dppe)] (4) and [Fe3(CO)7(µ3-PPh)2(µ-κ2-dppf)] (5) in moderate yields, together with small amounts of the corresponding [Fe3(CO)8(µ3-PPh)2(κ1-Ph2PxPPh2)] cluster (x = -C4H6-, -C2H2-, -C2H4-, -C3H6-, -C5H4FeC5H4-). The molecular structures of complexes 3 and 5 have been established by X-ray crystallography. Complexes 1–5 have been examined as proton reduction catalysts in the presence of p-toluenesulfonic acid (p-TsOH) in CH2Cl2. Cluster 1 exhibits two one-electron quasi-reversible reduction waves at –1.39 V (ΔE = 195 mV) and at –1.66 V (ΔE = 168 mV; potentials vs. Fc+/Fc). Upon addition of p-TsOH the unsubstituted cluster 1 shows a first catalytic wave at –1.57 V and two further proton reduction processes at –1.75 and –2.29 V, each with a good current response. The diphosphine-substituted derivatives of 1 are reduced at more negative potentials than the parent cluster 1. Clusters 2–4 each exhibit an oxidation at ca. +0.1 V and a reduction at ca. –1.6 V; for 4 conversion to a redox active successor species is seen upon both oxidation and reduction. Clusters 2–4 show catalytic waves in the presence of p-TsOH, with cluster 4 exhibiting the highest relative catalytic current (icat/i0 ≈ 57) in the presence of acid, albeit at a new third reduction process not observed for 2 and 3. Addition of the dppf ligand to the parent diphosphinidene cluster 1 gave cluster 5 which exhibited a single reduction process at –1.95 V and three oxidation processes, all at positive values as compared to 2–4. Cluster 5 showed only weak catalytic activity for proton reduction with p-TsOH. The bonding in 4 was investigated by DFT calculations, and the nature of the radical anion and dianion is discussed with respect to the electrochemical data.
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