Metal coordination architectures of N-acyl-salicylhydrazides: The effect of metal ions and steric repulsion of ligands to their structures of polynuclear metal complexes

摘要

Three polynuclear transition metal complexes [Mn-8(DMF)(8)(L1)(8)] center dot 4DMF (1), [Mn-6(DMF)(6)(L2)(6)] center dot [Mn-6(DMF)(4)(H2O)(2)(L2)(6)] center dot 2DMF (2), [Cu-3(L3)(2)(py)(2)] (3) of the pentadentate ligands N-acyl-salicylhydrazides were synthesized and characterized, their crystal structures were investigated. The oxidation state and properties of the central metal ions are important in crystal structure formation, trivalent Mn(III) ion which easily form stable octahedral coordination metallamacrocycle complexes, metallacrowns 1 and 2 were obtained; while bivalent Cu(II) ion is easier to form square planar, trinuclear complexes 3 was obtained. The steric effect of the N-acyl side chains also plays an important role in the structures of these polynuclear complexes. The magnetic property of 1 was also investigated. (c) 2008 Elsevier Ltd. All rights reserved.