CRYSTAL-GROWTH, CRYSTAL-STRUCTURE, OPTICAL, ELECTROOPTIC AND ELECTROSTRICTIVE PROPERTIES OF THE ORTHORHOMBIC TARTRATO-ANTIMONATE-(III) NITRATE KZN[SB2((-C4H2O6)2]NO3.5H2O (KZNSBTN)())

KZnSbTN is an example from the large acentric double salt-like family of tartrato-antimonates. Its crystal structure was determined from sin gle-crystal X-ray diffraction data (orthorhombic, P2(1)2(1)2(1), a = 8 .112(2) angstrom, b = 15.507(4) angstrom, c = 16.090(5) angstrom, Z = 4, D(x) = 2.600 Mg m-3, mu(MoKalpha) 2.855 mm-1, T = 293 K, R = 0.046 for 5320 unique reflections (I > 3sigma(I)). The main structural featu re is the (4-)-bridged binuclear tartrato-antimonate(III) complex [Sb2 {(+)-C4H2O6}2]2-. Single crystals of the title compound of up to 4 x 4 x 6 cm3 were grown from aqueous solutions at 35-degrees-C. The electr ostrictive tensor [d(ijk)] and the unclamped electro-optic tensor [r(i jk)sigma] were determined at room temperature and lambda = 633 nm. The maximum value of the electro-optic effect is two orders smaller than that of KH2PO4(KDP). The maximum electrostrictive constant is 1.3-time s greater than that of alpha-quartz.