Organometallics of diphosphazanes. V. The different coordination behaviour of cis- and trans-cyclodiphosphazanes towrds Group 6 metal carbonyl moieties

Article abstract of DOI:10.1016/0022-328X(92)88010-G

The reactions of cyclodiphosphazanes 2 (R = CH2CF3 (1) and C6H4Me-p (2)) with Group 6 metal carbonyl derivatives have been investigated.The stereochemistry of the ligand appears to play a significant role in determining its coordination behaviour.The cyclodiphosphazane 1 (isolated as the trans-isomer) affords the dinuclear complexes 9-11 in which the two metal centres are bridged by the diphosphazane ligand.In contrast the cyclodiphosphazane 2 (isolated as a 3/1 mixture of cis- and trans-isomers) yields the mononuclear complexes 3-7 in which the cyclodiphosphazane is coordinated in the η¹-fashion.The structures of > (6) and <2<μ-2>> (9a) have been determined by X-ray crystallography.