Synthesis, crystal structure and dielectric properties of a hybrid dihydrogen arsenate salt: (C9H11N4)H2AsO4

Abstract

The use of the organic aromatic amine molecule 5-amino-3-methyl-1-phenyl-1H-1,2,4-triazole to synthesize a dihydrogen arsenate hybrid salt leads to a supramolecular structure type. Single crystals of (C9H11N4)H2AsO4 were grown through slow evaporation in solution. The synthesized compound crystallizes in the monoclinic system with the non-centrosymmetric P21 space group according to the following parameters; a = 9.655 (3) Å, b = 4.7090 (15) Å, c = 14.022 (4) Å, β = 108.147 (5)° and Z = 4. The mineral part building from dihydrogen arsenate anions [H2AsO4]− is linked together and to the organic cations [C9H11N4]+ by hydrogen bonds only. The results of Hirshfeld’s analysis show that in all possible molecular contacts, the hydrogen–hydrogen and the oxygen–hydrogen are the most important interaction in the crystal (37.5 and 31.9%, respectively). The Fourier transform infrared (FT-IR) confirms the existence of vibrational modes corresponding to the organic amine molecule and mineral arsenate tetrahedron. The optimized molecular structure and the vibrational spectra were calculated by the density functional theory DFT methods and the semi-empirical PM3 calculations. Dielectric study of this compound has been measured in order to determine the electrical conductivity type giving rise to an activation energy of ΔEσ = 0.17 eV.