Crystal growth, crystal structure and linear optical properties of the non-centrosymmetric ammonium bis(nitrilotriacetato)zirconate and hafnate, (NH4)2[Zr{N(CH2COO)3}2] and (NH4)2[Hf{N(CH2COO)3}2]

Large single crystals of ammonium bis(nitrilotriacetato)zirconate, (NH4)(2)[Zr{N(CH2COO)(3)}(2)] (to be written (NH4)(2)[Zr(NTA)(2)]), were grown. Linear optical properties were measured (indices of refraction and transparency range) and the phase matching conditions for second harmonic generation process were determined. Crystal structures of the zirconate and the isomorphic hafnate were solved from single crystal X-ray diffraction data (P3(1,2)21; Z = 3; Zr: a = 9.582(1) Angstrom, c = 16.611(4) Angstrom, Hf: a = 9.5846(5) Angstrom, c = 16.5920(8) Angstrom) and the geometry of the complex groups [Zr(NTA)(2)](2-) and [Hf(NTA)(2)](2-) was analysed.