Crystal structure and properties of terbium o-methylbenzoate complex with 1,10-phenanthroline [Tb(o-CH3C6H4COO)3(C12H8N2)]2

A terbium o-methylbenzoate complex with 1,10-phenanthroline, Tb(o-MBA)(3)phen (where o-MBA = o-methylbenzoate and phen = 1,10-phenanthroline) was prepared from ethanol solution and its crystal structure was determined by X-ray diffraction. The crystal of the complex Tb(o-MBA)(3)phen belongs to triclinic crystal system and P1 (#2) space group. The crystal data are as follows: a = 1.4371(4) nm, b = 1.7387(2) nm, c = 1.3109(2) nm, alpha = 96.37(1)degrees, beta = 107.21(2)degrees, gamma = 82.78(2)degrees, V = 3.094(1) nm(3), Z = 2, M-r = 1489.12, D-c = 1.598 g(.)cm(-3), mu = 2.330 mm(-1) and F(000) = 1488.00. The final R and R-w are 0.038 and 0.047 for 8668 [I > 2sigma (I)] unique reflections, respectively. In the complex each Th3+ ion is eight-coordinated by one 1,10-phenanthroline molecule, one bidentate carboxylate group and four bridging carboxylate groups. The carboxylate groups are bonded to the terbium ion in two modes: the chelating bidentate and the bridging bidentate. Excitation and luminescence data observed at room temperature show that the title complex emits strong green fluorescence under ultraviolet light. The results of thermal analysis indicate that the complex Tb(o-MBA)(3)phen is quite stable to heat.