A deliberate approach for the syntheses of heterometallic supramolecules containing dimolybdenum Mo24+ species coordinated to other metal units

Abstract

Two compounds with quadruply bonded Mo₂⁴⁺ species having isonicotinate ligands bound through the carboxylate group have been designed to act as anglers by luring metal-containing Lewis acids to bind to the N-pyridyl group. The corner pieces are Mo₂(DAniF)₃(O₂CC₅H₄N) (1) and cis-Mo₂(DAniF)₂(O₂CC₅H₄N)₂ (2), DAniF = N,N′-di(p-anisyl)formamidinate. The heterometallic molecular rods 1-Ni(acac)₂-1 (3) and 1-Rh₂(O₂CCH₃)₄-1 (4) were made by reaction of 1 with Ni(acac)₂ and the metal–metal bonded species Rh₂(O₂CCH₃)₄, respectively. In these compounds either a mononuclear or a dinuclear species are sandwiched between two molecules of 1. The cisoid compound 2 has been employed for the synthesis of a molecular rhombus, [2-Zn(Cl₂)]₂ (5). The successful syntheses and isolation of 3–5 show that the use of corner pieces with angler groups is an excellent approach for making heterometallic supramolecular compounds having a combination of metal–metal bonded units and other metal species.