Structural Characterization of Some Complexes of Group 13 Metal(III) Nitrates with N,N′-Bidentate Bases

The structural characterization of several novel complexes of gallium(iii) and indium(iii) nitrates, crystallized with 2,2′-bipyridyl (bpy) and 1,10-phenanthroline (phen) from nitromethane solution, is presented. The adduct In(NO3)3:bpy (1:2) is of the form [(ONO2)(O2NO)2In(bpy)2], rather than [(ONO2)3ML2] as found for the larger M = Ln (rare earth), Bi, despite similar 2-symmetry. Several hydroxo-bridged dimers, [L2M(OH)2ML2](NO3)4(·S) are also presented, the cations all of the same isomeric form. [(ONO2)(bpy)In(OH)2In(bpy)(O2NO)], interestingly, displays two different forms within the one crystal, by virtue of different dispositions of the coordinated nitrate. The structures of related cis-[(phen)2GaBr2]Br(·S) and [(en)2In(OH)2In(en)2](NO3)4 (en = H2N(CH2)2NH2) are also described, the latter isomorphous with its cobalt(iii) counterpart.