Reactions of dicarbonyltitanocenes with 2-diazo-1,3-diketones: O-,N- versus O-,O- chelation and self-assembly of a novel heteroleptic Ti5O6-cage compound

Reaction of 2-diazo-1,3-diketones with titanocene precursors can produce fi ve-, six- or seven-membered l-titana-2,n-diheterocyclic complexes with diff erent coordination modes: whereas reaction with dicarbonyltitanocene is fas t and furnishes either five-membered titanaoxazacycles or C-C coupled seven -membered dioxochelates, decamethyltitanocene dicarbonyl reacts sluggishly to give a novel heteroleptic, trigonal-bipyramidal oxygen bridged Ti5O6-clu ster containing six unsymmetric six-membered titanadioxacyclic ligands. (C) 2000 Elsevier Science S.A. All rights reserved.