{Bis[bis(trimethylsilyl)methyl]stannio(II)}bis(η 2 ‐ethen)nickel(O) und verwandte Verbindungen, Teil I

{Bis[bis(trimethylsilyl)methyl]stannio(II)}bis(η 2 ‐ethene)nickel(O) and Related Compounds, Part I The reaction of Ni(C 2 H 4 ) 3 and bis{bis(trimethylsilyl)methyl}‐stannene affords the crystalline, coordinatively unsaturated complex (C 2 H 4 ) 2 Ni Sn{CH(SiMe 3 ) 2 } 2 ( 1 ). The NMR spectra of 1 show for the tin moiety a temperature‐dependent solvate complex formation (thf) and for the nickel moiety a hindered rotation of the ethene ligands at low temperature. X‐ray structure analysis indicates Sn – Ni multiple‐bond character. Upon addition of donor molecules to 1 the addition compounds (C 2 H 4 ) 2 Ni – Sn{CH(SiMe 3 ) 2 } 2 (donor) [donor = NH 3 : 2a ; pyridine: 2b ; (Me 2 N) 3 PO: 2c ] are obtained. According to the low‐temperature NMR spectra the complexes are asymmetric in their ground state. Similar to the formation of the adducts 2a – c , the title compound 1 reacts with LiHAliBu 3 as a source of LiH in ether/tmeda to form the hydride adduct [Li(tmeda) 2 ]+ [(C 2 H 4 ) 2 Ni – Sn{CH(SiMe 3 ) 2 } 2 } 2 (H)]ominus; ( 2d ). Displacement of the ethene ligands in 1 by CO yields with conservation of the Ni – Sn bond the complex (CO) 3 Ni Sn{CH(SiMe 3 ) 2 } 2 ( 3 ). From this complex the donor adducts (CO) 3 Ni – Sn{CH(SiMe 3 ) 2 } 2 (donor) [donor = NH 3 : 4a ; pyridine: 4b ; (Me 2 N) 3 PO: 4c ] are prepared. For the donor‐ligand carbonyl complexes the ground state has been shown to be asymmetric by low‐temperature NMR spectra.