36477-75-5Relevant academic research and scientific papers
Donor/acceptor complexes containing ferrocenyl-pyridine ligands attached to a tungsten carbonyl centre: Structural, spectroscopic and electrochemical properties
Sakanishi, Sumika,Bardwell, David A.,Couchman, Samantha,Jeffery, John C.,McCleverty, Jon A.,Ward, Michael D.
, p. 35 - 45 (1997)
A series of ferrocenyl-pyridine ligands (Fc-L) in which a 4-pyridyl side-arm is attached to a ferrocenyl core via a conjugated linker has been attached to tungsten carbonyl cores, giving complexes of the type [(Fc-L)W(CO)5] (1-6) and [(Fc-L)2W(CO)4] (7 and 8). Three of these complexes were characterised by X-ray crystallography. Complex 2, [{Fc-C(Ph)=CH-C5H4N}W(CO)5]: triclinic, P1; a = 9.329(4), b= 12.115(3), c= 12.745(3) A; α = 66.66(2), β = 71.87(2), γ = 81.40(2)°; Z = 2; 3230 unique data; R1=0.032, wR2 = 0.090. Complex 3, [{Fc-C(Me)=CH-C5H4N}W(CO)5]: triclinic, P1; a= 11.325(3), b= 12.328(2), c= 16.639(5) A; α = 79.83(2), β = 77.30(2), γ = 82.043(14)°; Z = 4; 5878 unique data; R1 = 0.035. wR2 = 0.103. Complex 7 · (CH2Cl2)0.5, [{Fc-CH = CH-C5H4N}2W(CO)4 · (CH2Cl2)0.5]: triclinic, P1; a= 10.290(2), b = 11.751(4), c = 16.328(4) A; α = 88.071(14), β = 83.502(14), γ = 67.50(2)°; Z = 2; 5054 unique data; R1 = 0.047, wR2 = 0.125. All of the complexes were fully characterised by 1H and 13C NMR, IR, UV-vis and luminescence spectroscopy, FAB mass spectrometry, and electrochemical measurements. The complexes show the expected spectroscopic and electrochemical features for both the ferrocenyl and substituted tungsten carbonyl chromophores. Although the individual molecules possess the necessary structural and electronic features required for second-order non-linear optical behaviour, the fact that the three crystallographically characterised complexes have centrosymmetric space groups precludes bulk solid-state measurements of NLO behaviour.
A stable N-heterocyclic carbene with a diboron backbone
Krahulic, Kelly E.,Enright, Gary D.,Parvez, Masood,Roesler, Roland
, p. 4142 - 4143 (2007/10/03)
The synthesis of a novel five-membered inorganic ring, a stable N-heterocyclic carbene with a diboron backbone, is reported. A pentacarbonyltungsten complex containing the new carbene is also described. Spectroscopic evidence indicates that the sterically
Dicarbonylcyclopentadienyliridium, (η-C5H5)Ir(CO)2, as a ligand
Jiang, Faming,Biradha, Kumar,Leong, Weng Kee,Pomeroy, Roland K.,Zaworotko, Michael J.
, p. 1327 - 1335 (2007/10/03)
The following complexes, in which CpIr(CO)2 acts as a 2e donor ligand, have been prepared: Cp(OC)2IrW(CO)5 (1), Cp(OC)2IrRu(CO)3(SiCl3)2, Cp(OC)2IrOs(CO)3(GeCl3)(Cl) (2), Cp(OC)2IrOs(CO)3(X)2 (X = Cl, Br (3), I). The characterization of the complexes included the crystal structures of 1, 2, and 3, which reveal that all contain an unbridged metal-metal bond. The carbonyl ligands of 1 in solution undergo exchange on the NMR time scale above -40°C. With the exception of 2, all the complexes dissociate in solution at room temperature, some rapidly so. Only in the case of 3 is an equilibrium with the dissociation products established. The results indicate that CpIr(CO)2 is a weak ligand.
Reduction of CO2 and other substrates using photochemical reactions of the W2(CO)102- complex
Silavwe, Ned D.,Goldman, Alan S.,Ritter, Robin,Tyler, David R.
, p. 1231 - 1236 (2008/10/08)
The photochemistry of the W2(CO)102- complex was investigated with the goal of determining if irradiation of this dimer generates a powerful reducing agent, presumably a 19-electron species. In general, the photochemistry of the W2(CO)102- complex is comparable to that of other metal-metal-bonded carbonyl dimers. Irradiation into the low-energy tail of the d π → σ* electronic transition of the W2(CO)102- complex led to W-W bond homolysis. The resulting 17-electron W(CO)5- radicals could be trapped with suitable ligands such as 4-cyanopyridine to give 19-electron adducts . (See ref 3 for an important definition of the phrase 19-electron adduct .) Evidence is presented that the ligands PPh3 and PBu3 also react with photogenerated W(CO)5- to form adducts: W(CO)5- + PR3 → W(CO)5PR3-. These adducts are powerful reducing agents, and they were used to reduce CO2 to formate and CO. The only organometallic product formed in the reaction was W(CO)5PPh3, the oxidized form of the 19-electron complex. In a similar manner, Mn2(CO)10 was reduced to Mn(CO)5-, Cp2Co+ to Cp2Co, benzophenone to the radical anion, and methylviologen (MV2+) to MV+. Alternative reduction mechanisms involving the W(CO)5- radical, W(CO)52-, or HW2(CO)10- as reductants were shown not to be operating. Nineteen-electron complexes generated by irradiation of Cp2Mo2(CO)6 proved incapable of reducing CO2.
The Formation, Structure, and Reversible Carbonylation of (?5-C5H5)MM'(CO)7(SR)) Complexes; Reactions of ((?5-C5H5)MM'(CO)8(SR)) with Hexafluorobut-2-yne
Guerchais, Jacques E.,LeQuere, Jean L.,Petillon, Francois Y.,Manojlovic-Muir, Ljubica,Muir, Kenneth W.,Sharp, David W. A.
, p. 283 - 290 (2007/10/02)
The action of heat on ((?5-C5H5)(OC)3M(μ-SR)M'(CO)5) (1) (M or M'=Cr, Mo, or W; R=Me or Ph) gives (2) containing a metal-metal bond.Photolysis of (2) in the presence of carbon monoxide regenerates (1) in an example of reversible cleavage of a M-M bond by carbon monoxide.The octacarbonyls (1) react with hexafluorobut-2-yne to give products of substitution at the (?5-C5H5)M group.The spectroscopic parameters of the complexes and crystal-structure analyses of (1a; M=M'=W, R=Me), (2b; M=Mo, M'=W, R=Me), and ((?5-C5H5)(OC)(CF3C2CF3)W(μ-SMe)W(CO)5) (5) are discussed in terms of the electronic properties of the bridging thiolato-group and the metal centres.
