New Noncentrosymmetric Material - [N(CH3)4]ZnCl3: Polar Chains of Aligned ZnCl4 Tetrahedra

A new organically templated noncentrosymmetric polar zinc chloride, [N(CH3)(4)]ZnCl3, has been synthesized hydrothermally, and the structure was determined by single crystal X-ray diffraction. The reported material exhibits a unidimensional crystal structure consisting of chains of anionic ZnCl4 tetrahedra that are separated by [N(CH3)(4)](+) cations. Second-harmonic generation (SHG) measurement on the noncentrosymmetric [N(CH3)(4)]ZnCl3, using 1064 nm radiation, indicate the material has a SHG efficiency of approximately 15 x alpha-SiO2. Additional SHG measurements indicate the material is nonphase-matchable (type 1). In addition, converse piezoelectric measurements revealed d(33) values of 10 pm/V. Thermogravimetric analysis, UV-vis diffuse reflectance, and infrared spectroscopy were also performed, as were electronic structure calculations.. Crystal data: [N(CH3)(4)]ZnCl3, orthorhombic, space group Pmc2(1) (No. 26), with a = 7.2350(14) angstrom, b = 8.8210(18) angstrom, c = 15.303(3) angstrom, V = 976.6(3) angstrom(3), and Z = 4.