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Synthesis and some reactions of a terminal carbyne complex of osmium. Crystal structures of Os(CR)Cl(CO)(PPh3)2 and gCl]R)Cl(CO)(PPh3)2

1986; Elsevier BV; Volume: 315; Issue: 2 Linguagem: Inglês

10.1016/0022-328x(86)80439-9

1872-8561

George R. Clark, Catherine M. Cochrane, Karen Marsden, W.R. Roper, L.J. Wright,

Synthetic Organic Chemistry Methods

The reaction of two equivalents of LiR (R = p-tolyl) with the dichlorocarbene complex OsCl2(CCl2)(CO)(PPh3)2 gives the carbyne complex Os(CR)Cl(CO) (PPh3)2 (I) in good yield. X-ray crystal structure determination shows that I is mononuclear with an OsC distance of 1.78(2) Å. The OsC bond reacts with electrophiles rather than nucleophiles. Thus, HCl adds to give the alkylidene complex OsCl2(CHR)(CO)(PPh3)2, Cl2 forms OsCl2(CClR)(CO)(PPh3)2 and sulphur, selenium and tellurium react to yield to corresponding dihapto-chalcoacyls Os(η2-C[X]R)Cl(CO)(PPh3)2 (X = S, Se, Te). Group Ib metal halides also add to the OsC bond to form the adducts Os(C[MX]R)Cl(CO)(PPh3)2 (MX = CuI, AgCl, AuCl). The X-ray crystal structure determination of Os(C[AgCl]R)Cl(CO)(PPh3)2 (II) suggests that this complex can be considered as a dimetallacyclopropene derivative. Crystals of I are monoclinic, space group P21/n, a 17.030(2), b 12.774(1), c 18.315(3) Å, β 107.96 (1)°, V 3793.2 Å3, Z = 4, Dm 1.53(1), Dc 1.54. Crystals of II are monoclinic, space group P21/n, a 13.021(2), b 23.714(2), c 12.999(2) Å, β 90.556(2)°, V 4013.7 Å3, Z = 4, Dm 1.705(5), Dc 1.695. The structures were solved by conventional heavy-atom methods, and refined by full-matrix least-squares employing anisotropic thermal parameters for all non-hydrogen atoms except for the carbon atoms of the phenyl rings. Phenyl hydrogen atoms were included in calculated positions. Final residuals R were 0.040 and 0.037, respectively.