GALLIUM AND INDIUM COMPLEXES OF HEXADENTATE LIGANDS CONTAINING PENDANT PYRIDYL AND PHENOLATE GROUPS

{Gallium and indium complexes of N,N’-bis(2-hydroxybenzyl)-N,N’-bis(2-methylpyridyl)ethylenediami (H(2)bbpen), N,N’-bis(S-bromo-2-hydroxybenzyl)-N,N-bis(2-methylpyridyl)ethylenediamin e (H(2)Bbbpen), and N,N’-bis(5-chloro-2-hydroxybenzyl)-N,N-bis (2-methylpyridyl)ethylenediamine (H(2)Clbbpen) were prepared and characterized by spectroscopic techniques and crystallographic analyses. H(2)bbpen, H(2)Brbbpen, and H(2)Clbbpen were prepared in excellent yield by the reactions of 2-picolyl chloride with N,N’-bis(2-hydroxybenzyl)ethylenediamine (H-2- bben),N,N’-bis(S-bromo-2-hydroxybenzyl)ethylenediamine (HzBrbben), and N,N’-bis(S-chloro-2-hydroxybenzyl)ethylenediamine (H(2)Clbben), respectively. Characterization of H(2)bbpen and its substituted analogs showed these compounds to be symmetrical about the ethylene moiety of the ethylenediamine backbone. This symmetry is maintained in the metal complexes of these compounds. There are six potential sites for coordination to a metal ion: two amine nitrogens, two phenolate oxygens, and two pyridyl nitrogens. A series of monocationic metal complexes were obtained from the reactions of Ga3+ and In3+ with H(2)bbpen, H(2)Brbbpen, and H(2)Clbbpen in the presence of 2 equiv of base (acetate). Crystals of [Ga(Clbbpen)]ClO4 are triclinic, of space group P ($) over bar 1, with 11.1563(6) Angstrom