Six-coordinate vanadyl tetradentate Schiff base complexes with methanol, methoxide, water or fluoride as the sixth ligand

The reaction of [(VO)-O-IV(L)] (where L is a tetradentate dianion derived f rom a Schiff base H2L) with acids and air generates the species [(VO)-O-V(L )](+). These were shown earlier to be stable and to form adducts with the o riginal V-IV material. We show here how a limited range of bases including MeOH, OMe-, F-, and even H2O can also form adducts with the VV cation. The crystal structures of six such adducts are described, namely [VO(hapen)(MeO H)](ClO4), [VO{salen(5-Me)(2)}(MeOH)](ClO4), [VO{salen(5-Cl)(2)(MeOH)](ClO4 ), [VO(salibn)(H2O)](CF3SO3), [{VO{salen(5-Cl)(2)}}(2)(mu -F)][BF4] and [{V O{salen(5-Br)(2)}}(mu -F][BF4]. (C) 2000 Elsevier Science B.V. All rights r eserved.