Synthesis and molecular structures of novel seven-co-ordinated oxo- and nitrido-rhenium(V) complexes of 2,2′ : 6′,2″ : 6″,2‴-quaterpyridine

Abstract

Reaction of [ReO₂(PPh₃)₂I] and [ReNCl₂(PPh₃)₂] with 2,2′ : 6′,2″ : 6″,2‴-quaterpyridine (L) in methanol gave [ReO(L)(OMe)₂]ClO₄ and [ReN(L)(PPh₃)Cl]ClO₄ respectively. The structures determined by X-ray crystallography revealed seven-co-ordination around rhenium with ReO and ReN distances of 1.666(4) and 1.647(6)Å respectively. Intense metal-to-ligand charge-transfer transitions in the visible region and reversible Re^VI–Re^V redox couples have been observed for both complexes in acetonitrile.