Crystal Structure and Properties of a Terbium m -methylbenzoate Complex with 1,10-phenanthroline

A terbium m -methylbenzoate complex with 1,10-phenanthroline, [Tb( m -MBA) 3 phen]·H 2 O has been obtained from ethanol solution, where m -MBA= m -methylbenzoate and phen=1,10-phenanthroline, and its structure determined by X-ray diffraction methods. The unit cell contains binuclear molecules of the title compound. Each Tb 3+ ion is eight-coordinated to one 1,10-phenanthroline molecule, one bidentate carboxylate group and four bridging carboxylate groups, for which the carboxylate groups are bonded to the terbium ion in two modes chelating bidentate and bridging bidentate. Excitation and luminescence data observed at room temperature show that the complex emits very intense green fluorescence under ultraviolet light. Results of thermal analysis indicate that the complex is quite stable to heat.