[Tb(pyrazinecarboxylic acid)3(H2O)2] • 6n H2O: synthesis, structure and photoluminescence

A novel terbium compound [Tb(pyrazinecarboxylic acid)(3)(H2O)(2)] center dot 6n H2O (1) has been prepared via hydrothermal reaction and structurally characterized by single-crystal X-ray diffraction. The crystal belongs to the orthorhombic, space group Pbca with a = 19.4112(7), b = 11.9345(4), c = 19.8507(7) angstrom, V = 4598.7(3) angstrom(3), Z = 8, C15H25N6O14Tb, M-r= 672.33, D-c = 1.942 g/cm(3), S = 1.052, mu(MoK alpha) = 3.159 mm(-1), F(000) = 2672, R = 0.0190 and wR = 0.0423. Compound 1 features an infinite 1-D chain-like structure with the terbium ions coordinating to six oxygen and three nitrogen atoms to give a distorted monocapped square antiprism. The [Tb(pyrazinecarboxylic acid)(3)(H2O)(2)](n) chains and the lattice water molecules link to each other through pi-pi interactions and hydrogen bonding interactions to construct a 3-D supramolecular network. Photoluminescent investigation reveals that the title compound displays strong emissions that are attributed to the characteristic emissions of D-5(4) -> 7F(J) (J = 3, 4, 5, 6) of Tb3+ ions.