Koordinationsverhalten vinyl- und alkinylfunktionalisierter chlorsilane

Abstract

The coordination ability of vinyl and alkynyl substituted chlorosilanes of type (H 2C  CH)(R)SiCl 2 (1a R  Cl, 1b R  CH 3, 1c R  C  CPh), (H 2C  CH)(PhC  C)(R)SiCi) [1d R  N(SiMe 3) 2, 1e R  C  CPh], as well as of the disiloxane [(H 2CCH)(PhCC) 2Si] 2O ( 11) towards different organometallic compounds, such as Fe 2(CO) 9 ( 2), MnCp(CO) 3 ( 4, Cp  η 5-C 5H 5) and Co 2(CO) 8 (6) is discussed. Treatment of the vinylchlorosilanes 1a and 1b with Fe 2(CO) 9 (2) or MnCp(CO) 3 (4) in n-pentane or n-hexane produces the compounds [( η 2-H 2CCH)ML n ](R)SiCl 2 [3a ML n  Fe(CO) 4, R  Cl; 3b ML n  Fe(CO) 4, R  CH 3; 5a ML n  MnCp(CO) 2, R  Cl; 5b ML n  MnCp(CO) 2, R  CH 3] in which the vinyl units is η 2-coordinated to an Fe(CO) 3 or MnCP(CO) 2 moiety. While compounds 1a and 1b do not react with Co 2(CO) 8 (6) under similar applied reaction conditions, it is found that the alkynyl substituted chlorosilanes 1c–1e yield on addition of Co 2(CO) 8 the complexes [ η 2-CCPh)Co 2(CO) 6](H 2CCH))R)SiCl [7a R  Cl, 7b R  N(SiMe 3) 2, 7c R  CCPh] or [( η 2-CCPh)Co 2(CO) 6] 2(H 2C CH)SiCl (7d) respectively, In these compounds, the phenylethinyl ligands are χ 2-coordinated to a Co 2(CO) 6 fragment, thus forming bulky dicobalta-tetrahedrane units. Hydrolysis of compound 7c produces the disiloxane {[( χ 2-CCPh)Co 2(CO) 6](H 2C=CH)(PhCC)Si) 2O (9). Additionally, this compound can be synthesized by the reaction of [(H 2C=CH)PhCC) 2Si] 2O (11) with two equivalents of Co 2(CO) 8 (6). On treatment of 6 with one equivalent of the disiloxane 11 the formation of compound [( χ 2-CCPh)Co 2(CO) 6](H 2C=CH)(PHCC)SiOSi(HC=CH 2 (CCPh) 2 (12) is obtained. All compounds were characterized by analytical and spectroscopic data (1R, 1H, 13C, 29Si NMR, MS). The solid state structures of compounds [( χ 2-CCPh)Co 2(CO) 6](H 2C = CH)SiCl 2 (7a) and [( χ 2-CCPh)Co 2(CO) 6](H 2C =CH)(PhC=C)SiCl (7e) are reported. Complexes 7a and 7e crystallize in the triclinic space group P l with the following cell parameters: 7a a - 816.8(3), b = 1597.5(9), c = 1601.5(8) pm, α = 101.49(4), β = 100.01(4), γ = 96.55(4)°, V = 2003(1) × 10 6pm 3and Z = 4; 7c a = 827.6(2), b = 914.0(2), c = 1696.7(5) pm, α = 89.35(2), β = 76.75(2), γ = 84.05(2)°, V = 1242(1) × 10 6pm 3and Z = 2.