Hydrothermal synthesis and structural characterization of two new three-dimensional oxyfluorinated titanium phosphates Ti_4(HPO_4)_2(PO_4)_4F_2·C_4N_2H_(12)·H_2O and Ti_4(HPO_4)_2(PO_4)_4F_2·C_2N_2H_(10)·H_2O

摘要

Two new organo-templated three-dimensional fluorinated titanium phosphates Ti_4(HPO_4)_2(PO_4)_4F_2·C_4N_2H_(12)·H_2O 1 and Ti_4(HPO_4)_2(PO_4)_2F_2·C_2N_2H_(10)·H_2O have been prepared hydrothermally in the presence of piperazine (C_4N_2H_(10)) and ethylenediamine (C_2N_2H_8) as templates, respectively. The assynthesized products are characterization by powder X-ray diffraction, IR spectroscopy, and thermogravimetric and differential theraml analyses (TG-DTA). The structures have been solved by single-crystal X-ray diffraction analysis. The compound 1 crystallized in the monoclinic space group Ca/c (no. 15), with M = 907.61 g/mol, a = 16.6549(17)A, b = 6.3378(6) A, c = 22.208(2) A, #beta# = 94.852(4) deg, V = 2335.7(4) A~3, Z = 4. R_1 [I>2#sigma#(I)] = 0.0393, wR_2[I>2#sigma#(I)] = 0.0=1071 and the compound 2 in the monoclinic space group C2/m (no. 12), with M = 880.56 g/mol, a = 16.6324(14) A, b = 6.3219(6) A, c = 11.0725(10) A, #beta# = 94.362(2)deg, V = 1160.88(18) A~3, Z = 2 R_1[I >2#sigma#(I)] = 0.0461, wR_2[I > 2#sigma#(I)] = 0.1403. They have similar three-dimensional frameworks built up from TiO_6, TiO_5F octahedral, PO_4 and PO_3(OH) tetrahedral units. There exist two types of 8-membered ring channles along the b axis in which the diprontonated piperazine or ethylenediamine molecules are entrapped and along the c axis in which water molecules are entrapped.