SYNTHESIS AND STRUCTURE OF 3,5-DIAMINO-1,2,4-TRIAZOLIUM TETRACHLORO-GALLATE

Abstract

This paper discusses the synthesis and structure of a complex compound based on 3,5-diamino-1H-1,2,4-triazole (guanazole) with gallium ions, formed by the interaction of anhydrous gallium (III) chloride and guanazole in dried methanol. After distilling off the solvent under vacuum, the resulting product was washed with hexane, acetone. The target compound was extracted with acetonitrile, and slow evaporation of the latter at room temperature for three days resulted in beige-colored crystals, which were characterized by IR spectroscopy, elemental analysis, mass-spectrometry and X-ray diffraction analysis. The complex composition of gallate, C2H6N5+∙[GaCl4], exists as two crystallographically independent cations and two anions. The complex compound crystallizes in the centrosymmetric space group of the monoclinic syngony. The tetrachlorogallate anion is a slightly distorted tetrahedron, which is typical of structures of this type. 1,2,4-triazolium cations are selectively protonated on the N4 and N4A atoms, however, the site of the preferential localization of the positive charge is the N2 and N2A atoms. In addition to the electrostatic interaction of oppositely charged ions, a developed system of hydrogen bonds plays an important role in the stabilization of the crystal packing: almost all hydrogen and chlorine atoms are involved in its formation. Each of the crystallographically independent cations forms a centrosymmetric dimer due to the intermolecular hydrogen bond N2 – H2···N3 and N2A – H2A···N3A.  A full set of X-ray data is deposited into the Cambridge Structural Database of Compounds - the Cambridge Structural Database (Contributor CCDC 1894815) and it can be gotten from the site www.ccdc.cam.ac.uk/data_request/cif.