Gehinderte ligandenbewegungen in übergangsmetallkomplexen : XIII. Oktaedrische monoolefinkomplexe des wolframs☆

摘要: Abstract Octahedral monoolefin complexes of the structural types cis -W(CO) 4 [As(CH 3 ) ](olefin) (A), [P(CH (B), and W- abf -(CO) - ce -[P(CH ] 2 (olefin) (C) have been prepared photochemically from W(CO) 5 ], in THF via corresponding THF-complexes with olefins ethylene (I), dimethylmethylenemalonate (II), dimethylmaleate (III), dimethylfumarate (IV). Informations about ligand properties I–IV were obtained IR NMR measurements. The carbomethoxy-substituted ligands II, III IV show temperature dependent spectra indicating hindered rotations these ligands, for which activation barriers determined. low prove preference parallel alignments coordinated CColefin bonds tungstenarsenic or tungstenphosphorous-bonds all complexes. In IVA IVB one two carbomethoxy groups can be frozen out at 133 K different positions, this is explained steric interactions between arsine phosphine ligand, respectively ester group.