SYNTHESIS, CRYSTAL STRUCTURE, AND PROPERTIES OF A NEW LANTHANIDE TARTRATE COORDINATION POLYMER

摘要

A new coordination polymer of terbium tartrate [Tb(H_2O)_3(C_4H_5O_6)(C_4H_4O_6)] has been synthesized and crystallizes in the polar space group P4_1 with cell constants a = 6.0415(9), b = 6.0415(9), c = 36.516(7) A, V = 1332.8(4) ?~3, Z = 4. The terbium(III) ion of title complex is nine-coordinate through oxygen donors. Four different coordination modes of tartrate occur. This Tb(III) complex exhibits a characteristic luminescence in the visible region upon excitation at 353 nm. The temperature-dependent magnetic properties of the Tb(III) complex were investigated in the temperature range of 2-300 K. Title compound exhibits significant ferroelectric properties at room temperature (remnant polarization 2P_r = 0.160 μC cm~(-2), coercive field 2E_c = 44.5 kV cm~(-1), saturation of the spontaneous polarization P_s = 0.176 μC cm~(-2)).