{Bis[bis(trimethylsilyl)methyl]stannio(II)}bis(η2-ethen)nickel(0) und verwandte Verbindungen. II

The coordinatively unsaturated (16e) (ethene)nickel(0) stannylene complex (C 2 H 4 ) 2 Ni=Sn{CH(SiMe 3 ) 2 } 2 (1) reacts with 1,6-heptadiene with preservation of the Ni=Sn bond to yield B quantitatively the 1,6-diene derivative (η 2 ,η 2 -C, 7 H 12 )Ni=Sn-{CH(SiMe 3 ) 2 } 2 (2). The alkene ligands of both 1 and 2 are readily displaceable. Compounds 1 and react with butadiene at -50°C by a 4-e oxidation of the metal-metal pair Ni(0)/Sn(II) to Ni(II)/Sn(IV) and concomittant reduction of two butadiene molecules to butenediyl moieties to afford stereoselectively the 16-e complex Ni-cis-{η 3 (Ni),η 1 (Sn)-anti-C 3 H 4 CH 2 } 2 Sn{CH(SiMe 3 ) 2 } 2 (3). Simirlarly, the reaction of 1 or 2 with isoprene yields regio- and stereoselectively the derivative Ni-cis-{η 3 (Ni),ν 1 (Sn)-anti-C 3 (3-Me)H 3 CH 2 } 2 Sn{CH(SiMe 3 ) 2 } 2