The reaction of salicylhydrazide with [ReOX3(PPh3)2]. Influence of X on product formation

The reactions of 2-hydroxybenzhydrazide (salicylhydrazide; Hshz) with trans-[ReOX3L2] (X = Cl (a), Br (b); L = PPh3] in acetonitrile and acetone were studied. With a in acetonitrile, the rhenium(III) complex [ReCl2(shz)(NCCH3)L2] (1), with shz coordinated as a monodentate diazenide, was isolated. However, with b in acetonitrile, the oxorhenium(V) dimer (μ-shd) [ReOBr(OPPh3)]2 (2) was formed. The bridging ligand shd4− was formed by the condensation of two shz ligands, with the elimination of hydrazine. In acetone, the reaction of Hshz with a produced [ReOCl2(sha)L] (3), in which the bidentate Schiff base ligand sha− was formed by the condensation of shz with acetone. The spectral and X-ray crystallographic characterization of complexes 1–3 are reported.