Molecular Structure of Five Inorganic-Organic Hybrid Crystals From N-Containing Aromatic Bases and Perchlorometallates of Cd2+, Co2+, Cu2+, and Zn2+

Abstract

Five organic-inorganic hybrid complexes [(HL1)2(CdCl4)] · H2O (1), (L1 = 2-methylquinoline); [(HL1)2(CoCl4)] · H2O (2), [(HL2)2(CuCl4)] (3), (L2 = 6-bromobenzo[d]thiazol-2-amine), [(HL3)2(ZnCl4)] · 2H2O, (4), (L3 = 5,7-dimethyl-1,8-naphthyri- dine-2-amine), and [(H2L4)(Cu2Cl8)0.5], and (5) (L4 = 3,6-bis(imidazol-1-yl)pyridazine) derived from N-containing aromatic Brønsted bases and metal(II) chloride (cadmium(II) chloride dihydrate, cobalt(II) chloride hexahydrate, copper(II) chloride dihydrate, and zinc(II) chloride) were prepared and characterized by IR, X-ray structure analysis, elemental analysis, and TG analysis. The aromatic rings of the cations in all of the compounds are essentially planar. On the structural level, the atomic arrangement of the title hybrid crystals can be described as built up by the perchlorometallates of Cd2+, Co2+, Cu2+, and Zn2+ associated to the organic cations through the multiple noncovalent associations. X-ray diffraction analysis revealed that complexes 1, 2, 4, and 5 have 3D network structures built from hydrogen bonds between the cations and chlorometallate anions, while 3 displays 2D doublesheet structure. The water molecules also played important role in structure extension in compounds 1, 2, and 4. The arrangements of the anions and cations in their solid state are dominated not only by the shape, size, and symmetry of the cations, but also by the different structure type of the chlorometallate anions as well as the hydrogen-bonded interactions existing in the crystal structures.