Cyclopentadienyl-ruthenium and -osmium chemistry: XXIV. Some complexes containing the olefinic tertiary phosphine 2-CH 2CHC 6H 4PPh 2 (sp): X-ray structures of one isomer of OsBr(sp)(η-C 5H 5), and of [formula omitted]Ph 2-2)(η-C 5H 5), containing an η 3-dithiocarboxylato group

Abstract

Reactions between MX(PPh 3) 2(η-C 5H 5) (M = Ru, X = Cl; M = Os, X = Br) and 2-CH 2CHC 6H 4PPh 2 afford MX(η 2-CH 2CHC 6H 4P Ph 2)(η-C 5H 5); the Os complex is obtained in two isomeric forms. The X-ray structure of the major isomer shows the CC double bond (OsC, 2.214, 2.195 Å; CC, 1.57 Å) is almost coplanar with the OsBr vector, with the terminal C cis to Br; the minor isomer is assumed to have the alternative, more sterically congested conformation, with the β-C cis to Br. The chlororuthenium complex reacts with NaOMe/MeOH to give the corresponding hydrido complex, which also exists as two isomers in solution; reaction of this complex with CS 2 gives the expected dithio acid derivative Ru(S 2CCHMeC 6H 4P Ph 2)(η-C 5H 5), together with small amounts of a complex assumed to be Ru[S 2C(CH 2) 2C 6H 4P Ph 2](η-C 5H 5). The X-ray structure of the major product reveals an unusual η 3-S 2C mode of coordination of the dithio acid fragment (RuS, 2.418, 2.426(1) Å; RuC 2.175(4) Å). Crystals of OsBr(η 2-CH 2CHC 6H 4P)Ph 2)( η-C 5H 5) are monoclinic, space group P2 1/ n, with a 12.696(2), b 21.719(6), c 15.929(3) Å, β 79.77(2)°, Z = 8; 2867 data ( I > 2.5σ( I)) were refined to R = 0.040, R w = 0.044. Crystals of Ru(η 3-S 2CCHMeC 6H 4P Ph 2)(η-C 5H 5) are orthorhombic, space group Pbca, with a 8.921(2), b 15.982(9), c 32.216(5) Å, Z = 8; 1685 data ( I > 2.5σ( I)) were refined to R = 0.027, R w = 0.030.