TRIGONAL PLANAR COORDINATION FOR SN(0) IN [(CP'(CO)2MN)2SNHAL]- - INIDENE-TYPE TIN-COMPOUNDS

The hydride complexes Na.([{L(CO)2Mn}2H]) (Na.1) (L = Cp, Cp', Cp star), react with tin halides Sn(Hal)2 to give dimanganastannacumulene compounds [L(CO)2Mn = Sn = Mn(CO)2L] (2). For L = Cp star the compound [Cp star(CO)2Mn = Sn = Mn(CO)2Cp star] (2a), which is already known, can be isolated. For L = Cp, Cp', 2 is only available in solution. In the presence of 2,2,2-Crypt, the cumulene intermediates 2 add the halide present in the solution forming the anionic ''inidene'' compounds [L(CO)2Mn Sn(Hal) Mn(CO)2L]- (4). For L = Cp' the compounds 4 (Hal = Cl (4a); Hal = Br (4b); Hal = I (4c)) are characterized by X-ray analyses. The compounds 4 show trigonal planar coordination around the bridging tin(0). Their geometry thus corresponds to the one observed at their isoelectronic neutral analogues with group 15 bridging elements [L(CO)2Mn...XR...Mn(CO)2L] (X = P, As, Sb, Bi). Synthesis and properties of the tin(0) complexes 4, as well as of tin(II) derivatives of type [{L(CO)2Mn}Sn(SR)3]- (3) are presented and discussed with regard to spectroscopic and structural data.