136444-72-9Relevant academic research and scientific papers
(Arene)osmium complexes containing alkynyl, vinyl, vinylidene, and thio- and selenoketene units as ligands: A series of organometallic compounds built up from 1-alkynes
Werner, Helmut,Weinand, Rudolf,Knaup, Wolfgang,Peters, Karl,Von Schnering, Hans Georg
, p. 3967 - 3977 (2008/10/08)
The reaction of [(C6H6)Os(PR′3)I2] (1, 2) with AgPF6 and 1-alkynes gives the osmium alkynyls [(C6H6)Os(C≡CR)(PR′3)I] (3-9), which on treatment with NaBH4 in methanol or ethanol afford the hydrido vinyl complexes [(C6H6)OsH(CH=CHR)(PR′3] (10-16) in good to excellent yields. Further experiments prove that the hydride ligand in these compounds is generated from the alkoxide ion. Complexes 10-16, in the presence of CCl4, CHBr3, and CH2I2, undergo metathesis to give the halogenovinylosmium derivatives [(C6H6)Os(CH=CHR)(PR′3)X] (17-26). The trans configuration at the vinylic carbon-carbon double bond has been confirmed by NMR spectroscopy as well as by a single-crystal X-ray investigation of [(C6H6)-Os(CH=CHPh)(PiPr3)I] (21). Compound 21 crystallizes in the space group C2/c with a = 23.323 (6) ?, b = 15.697 (7) ?, c = 15.832 (5) ?, and β = 117.42 (2)°. The osmium atom is surrounded by the four ligands in a quasi-octahedral configuration with a planar benzene ring and bond angles I-Os-P, I-Os-C, and P-Os-C of 85-92°. The halogeno vinyl complexes 19-21, 23, 25, and 26 react with tert-butyllithium at low temperature to form the osmium(0) vinylidenes [(C6H6)Os(=C=CHR)(PR′3)] (30-33). The reactivity of these metallaallenes is governed by the nucleophilicity of the Os=C bond. Therefore, on addition of electrophiles such as HX (X = Cl, CF3CO2), iodine, sulfur, and selenium the corresponding vinyl, thioketene, and selenoketene complexes 19, 22-26, 35, and 37-43 are obtained. The reaction of 30-32 with CuCl affords the heterometallic vinylidene-bridged compounds [(C6H6)(PR′3)Os(μ-C=CHR)CuCl] n (44-46), which on treatment with NaC5H5 or LiC5Me5 give the cyclopentadienyl and pentamethylcyclopentadienyl derivatives [(C6H6)(PR′3)Os(μ-C=CHR)Cu(C 5R5)] (47-49). From 30 and benzoyl azide, the E and Z isomers of the five-membered metallaheterocycle [(C6H6)(PiPr3)OsC(=CHPh)NC(Ph)O] (50) are prepared.
