摘要:
Two novel metal-fluorides [H2N(C2H4)(2)NH2][NbOF5](1) and [H2N(C2H4)(2)NH2][TaF2](2) have been obtained by a two-step hydrothermal method and characterized by elemental analysis, IR. PXRD, EDS. TG analysis and single-crystal X-ray diffraction. X-ray diffraction reveals that both compounds exhibit the supramolecular architectures through the electrostatic interactions and hydrogen bonding interactions between protonated piperazine and anions. In the [NbOF5](2-) of compound 1, the Nb atom moves from the center of the octahedron toward the oxide atom to form a short Nb=0 bond and long terminal Nb-F bond. In compound 2, the Ta atom can be described as a pentagonal bipyramidal geometry coordinated by seven fluorine atoms. Furthermore, the UV spectra in solid state of compounds 1 and 2 have also been discussed, which shows both of them have strong absorption bands. (C) 2010 Elsevier B.V. All rights reserved.