Tetranuclear manganese carboxylate clusters with imidazole-carboxylate chelating ligands. X-ray crystal structure of the 4-imidazoleacetate complex

Abstract

Procedures are described for the synthesis of tetranuclear manganese carboxylate complexes with ligands derived from 4-imidazoleacetic acid (imidacH) and 4-imidazolecarboxylic acid (imidcarbH). Reaction mixtures containing NBu4/(n)imidac or NHex4/(n)imidcarb generated in situ and either [Mn3O(O2CMe)6(py)3](ClO4) or Mn(O2CR)2, RCO2H (R = Me, Ph) and NR4/(')MnO4 (R' = Bu(n), Hex(n)) give red-brown solutions from which the products (NBu4/(n))[Mn4O2(O2CR)7(imidac)2] (R = Me (1); R = Ph (2)) and (NHex4(n))[Mn4O2(O2CR)7(imidcarb)2] (R = Me (3); R = Ph (4)) can be obtained. The X-ray crystal structure of 2 reveals that the anion consists of an [Mn4([μ3-O)2]8+ core with the four Mn atoms disposed in..