Synthesis, molecular structure and magnetic properties of a rhenium(IV) compound with catechol

A novel Re(IV) complex containing catechol as ligand has been prepared and characterized. The crystal structure of (HNEt3)(NBu4)[ReCl4(cat)]·H2cat was determined. The rhenium ion presents a distorted octahedral geometry, being bonded to a bidentate catecholate group and four chloride anions. The magnetic properties of the complex were studied, a /2D/ (the energy gap between ±3/2 and ±1/2 Kramers doublets) value of 190(10) cm−1. This is the largest /2D/ value reported for Re(IV) up to now.