Syntheses and characterization of mixed acetylacetonate–catecholate complexes of zirconium, [Zr3(acac)4(cat)4(MeOH)2], [Zr(acac)2(DBcat)]2 (H2DBcat = 3,5-di-tert-butylcatechol) and [Zr4(μ4-O)(acac)4(DBcat)3(OMe)4(MeOH)]

Abstract

Reactions of the acetylacetonate complex [Zr(acac)₄] with catechols have been investigated. Two crystalline complexes [Zr₃(acac)₄(cat)₄(MeOH)₂] 1 and [Zr(acac)₂(DBcat)]₂2 (H₂DBcat = 3,5-di-tert-butylcatechol) are isolated from the respective reactions in toluene, and their solid-state structures established by X-ray diffraction studies. Complex 2 consists of an edge-shared capped trigonal prismatic structure involving two symmetry related [Zr(acac)₂(DBcat)] units, while 1 is best visualized as a Zr₃ complex, possessing two [Zr(acac)₂(cat)(MeOH)] units linked to the central [Zr(cat)₂] fragment via four bridging catecholate ligands. Their reactivity was investigated; treatment of 2 with a trace amount of water in a solution of methanol and CH₂Cl₂ gave a Zr₄ oxo complex [Zr₄(μ₄-O)(acac)₄(DBcat)₃(OMe)₄(MeOH)] 3.