Two New Nonlinear Optical and Ferroelectric Zn(II) Compounds Based on Nicotinic Acid and Tetrazole Derivative Ligands

Two new zinc compounds, [Zn-2(mtz)-(nic)(2)(OH)](n)center dot 0.5nH(2)O (1) and [Zn(phtz)(nic)](2n) (2) (Hmtz = 5-methyltetrazole, Hphtz = 5-phenyltetrazole, Hnic = nicotinic acid), have been synthesized by a dual-ligand approach under solvothermal conditions. The compounds were characterized by single-crystal X-ray diffraction, elemental analysis, and infrared spectroscopy, respectively. The X-ray diffraction analysis reveals that both compounds exhibit a noncentrosymmetric polar packing arrangement. Compound 1 is a 3D framework constructed from the zigzag chain subunits of [Zn(nic)](+) with a 4-connected irl topology. Compound 2 possesses a 2D 4-connected sql topology constructed from the linear chain subunit of [Zn(nic)](+), which are linked together with phtz ligands. Impressively, both of the two compounds display second-harmonic generation response and ferroelectric behaviors. Furthermore, the photoluminescence of the compounds was also investigated.