NONPLANAR COORDINATION OF THE SCHIFF-BASE DIANION 2-DIMETHYLTRIMETHYLENEBIS[SALICYLIDENEIMINATE(2-)] TO VANADIUM

The Schiff-base dianion ltrimethylenebis[salicylideneiminate(2-)](saln ptn) coordinates to vanadium(IV) to form [VO(salnptn)] whose crystal s tructure has been determined. The compound is polymeric in the solid s tate with ... V=O --> V=O --> V=O ... chains, the salnptn donor atoms being coplanar and the salnptn framework umbrella-shaped. In the deriv ative [VO(OMe) (salnptn)], the crystal structure of which has also bee n determined. the OMe and the vanadyl oxygen are co-ordinated cis to e ach other, and the salnptn now occupies three equatorial and one axial co- ordination positions. Even N,N'-ethylenebis(salicylideneiminate) seems to behave analogously, though it is normally planar.