Inter-ligand interactions and the selective formation of the unusual metal–N3(adenine) bond in ternary copper(II) complexes with N-benzyliminodiacetato(2)) ligands

A novel mixed-ligand copper(II) complex with N-(p-methoxybenzyl)-iminodiacetato(2)) ligand (MOBIDA) and adenine (AdeH) of formula 1⁄2CuðMOBIDAÞðAdeHÞðH2OÞ H2O has been obtained. Its crystal structure reveals the selective formation of a rare Cu– N3(AdeH) bond, closely related to those reported by first time for compounds of general formula 1⁄2CuðBÞðAdeHÞðH2OÞ H2O, with B1⁄4N-benzylor N-(p-methylbenzyl)-iminodiacetato(2)) ligands. Appropriate structural comparison reveals that the copper(II) coordination by less basic N3 heterocyclic donor of the nucleobase is controlled by a molecular recognition process involving the formation of an intra-molecular inter-ligand N7(imidazole-like)–H O(carboxyl) bond and the inter-molecular inter-ligand p,p-stacking interaction between six membered rings of benzyl (MOBIDA) and AdeH. This stack generates multi-stacked infinite chains along the b-axis of the crystal. 2002 Elsevier Science B.V. All rights reserved.