Synthesis and Characterisation of Organic Antimony and Bismuth Chains and Cycles

Ring-chain equilibria between :i:cyclo:/i:-(Me:sub:3:/sub:SiCH:sub:2:/sub:Sb):sub:n:/sub: (n = 4, 5) and R´:sub:4:/sub:Sb:sub:2:/sub: (R´ = Me, Ph) contain the :i:catena:/i:-tristibanes R´:sub:2:/sub:Sb-SbR-SbR´:sub:2:/sub: (R´= Me, Ph; R = Me:sub:3:/sub:SiCH:sub:2:/sub:) as most abundant chain components. Addition of [nbdCr(CO):sub:4:/sub:] (nbd = norbornadiene) to the equilibrium mixture formed from :i:cyclo:/i:-(Me:sub:3:/sub:SiCH:sub:2:/sub:Sb):sub:n:/sub: (n = 4, 5) and R´:sub:4:/sub:Sb:sub:2:/sub: (R´ = Me, Ph) gives :i:cyclo:/i:-[Cr(CO):sub:4:/sub:(R´:sub:2:/sub:Sb-SbR-SbR-SbR´:sub:2:/sub:)] (R´= Me, Ph; R = Me:sub:3:/sub:SiCH:sub:2:/sub:), two complexes with :i:catena:/i:-tetrastibane ligands. Further reaction with [W(CO):sub:5:/sub:(thf)] (thf = tetrahydrofuran) leads to :i:cyclo:/i:-[Cr(CO):sub:4:/sub:(Me:sub:2:/sub:Sb-SbR-SbR-SbMe:sub:2:/sub:)W(CO):sub:5:/sub:] (R = Me:sub:3:/sub:SiCH:sub:2:/sub:). The reaction of the cyclo oligomers R:sub:n:/sub:Sb:sub:n:/sub:X:sub:n:/sub: (n = 2, 3; R = CH(SiMe:sub:3:/sub:):sub:2:/sub:; X = S, Se) with [W(CO):sub:5:/sub:(thf)] results in trapping of the dimers in :i:cyclo:/i:-[R:sub:2:/sub:Sb:sub:2:/sub:X:sub:2:/sub:][W(CO):sub:5:/sub:]:sub:2:/sub:. The crystal structures of several new organic antimony and bismuth chains and cycles could be determined via X-ray single crystal diffraction.