Metal imidazolato complexes: Synthesis, characterization, and X-ray powder diffraction studies of group 10 coordination polymers

Binary metal imidazolates of the group 10 metals have been prepared and typically found amorphous. However, the intermediacy of a number of (poly)crystalline species during their formation has been evidenced; their selective preparation and characterization, by chemical, spectroscopic, and thermal methods and their Structure solution by the ab initio X-ray powder diffraction technique lead to the discovery of new interesting structural features, such as those of polymeric Ni(Him)2(im)(CH3COO) (Him = imidazole) and of the hydrogen-bonded polymers of general PdxPt1-x(Him)2(im)2 formula (x = 0, 0.5, 1). The latter are built upon 2D frameworks of (pseudo)square meshes, which, in the pure Pd derivative, form an entangled structure based upon interpenetrating 2D layers, coupled in pairs. The different structures are discussed in terms of different conformations of the new "im-H-im" ligand, which acts as monoanionic exobidentate fragment, similar to im, pyrazolate (pz), "pz-H-pz", and pyrimidin-2-olate.