Hydrogen-bond supramolecular structure of group 13 Schiff base complexes

The structural features of the group 13 element complexes of general formula R2M(O,N) and RM(O,N)(2) (R = alkyl, M = B, Al, Ga, In), supported by bidentate and multidentate Schiff base ligands are discussed and considered in relation to the hydrogen-bond networks. Detailed structural analysis was performed for crystal structures of complexes retrieved from the Cambridge Structural Database (CSD) (version 5.25) and compounds recently characterized by our group. It was demonstrated that the intra- and intermolecular non-covalent interactions like the C-(HiminoO)-O-..., C-(HarylO)-O-..., C-(HaliphO)-O-..., and C-H(...)pi hydrogen bonds, and pi-stacking appear very frequently. Various structural motifs for the group 13 Schiff base complexes were delineated ranging from monomeric species, hydrogen bond dimers, linear polymers, helicates, layers to 3D network architectures. Such diversity in the supramolecular architecture arises from the ligands identity and both the coordination geometry and the nature of the metal center. (c) 2004 Elsevier B.V. All rights reserved.