Amine templated open-framework vanadium(iii) phosphites with catalytic properties
作者:Joseba Orive、Edurne S. Larrea、Roberto Fernández de Luis、Marta Iglesias、José L. Mesa、Teófilo Rojo、María I. Arriortua
DOI:10.1039/c2dt32286b
日期:——
Four novel amine templated open-framework vanadium(III) phosphites with the formula (C5N2H14)0.5[V(H2O)(HPO3)2], 1 (C5N2H14 = 2-methylpiperazinium), and (L)4−x(H3O)x[V9(H2O)6(HPO3)14−y(HPO4)y(H2PO3)3−z(H2PO4)z]·nH2O (2, L = cyclopentylammonium, x = 0, y = 3.5, z = 3, n = 0; 3, L = cyclohexylammonium, x = 1, y = 0, z = 0.6, n = 2.33; 4, L = cycloheptylammonium, x = 1, y = 0, z = 0, n = 2.33) were synthesized employing solvothermal reactions and characterized by single-crystal X-ray diffraction, ICP-AES and elemental analyses, thermogravimetric and thermodiffractometric analyses, and IR and UV/vis spectroscopy. Single-crystal data indicate that 1 crystallizes in the triclinic system, space group P, whereas 2, 3 and 4 crystallize in the hexagonal space group P63/m. Compound 1 has a two-dimensional motif with anionic sheets of [V(H2O)(HPO3)2]− formula, whose charge is compensated by the 2-methylpiperazinium cations embedded between the layers. In contrast, 2, 3 and 4 present a pillar-layer network giving rise to a three-dimensional framework containing intersecting 16-ring channels with the primary amine templates and the crystallization water molecules enclosed in them. 1, 2, 3 and 4 behave as heterogeneous catalysts for the selective oxidation of alkyl aryl sulfides, with tert-butylhydroperoxide (TBHP) as the oxidizing agent, being active, selective and recyclable for several successive cycles of reaction.
四种新型胺模板开放框架钒(III)次膦酸盐,其化学式为(C5N2H14)0.5[V(H2O)(HPO3)2],1 (C5N2H14 = 2-甲基哌嗪镎),以及(L)4−x(H3O)x[V9(H2O)6(HPO3)14−y(HPO4)y(H2PO3)3−z(H2PO4)z]·nH2O (2, L = 环戊基铵, x = 0, y = 3.5, z = 3, n = 0; 3, L = 环己基铵, x = 1, y = 0, z = 0.6, n = 2.33; 4, L = 环庚基铵, x = 1, y = 0, z = 0, n = 2.33),通过溶剂热反应合成并用单晶X射线衍射、ICP-AES和元素分析、热重和热差分析以及IR和UV/vis光谱进行了表征。单晶数据显示,1为三斜晶系,空间群P,而2、3和4为六方晶系,空间群P63/m。化合物1具有二维结构,含有[V(H2O)(HPO3)2]−阴离子层,其电荷由嵌入层间的2-甲基哌嗪镎阳离子补偿。相反,2、3和4呈现柱层网络,形成三维框架,包含相交的16元环通道,通道内含有主要胺模板和结晶水分子。1、2、3和4作为非均相催化剂,用于选择性氧化烷基芳基硫醚,以叔丁基过氧化氢(TBHP)为氧化剂,活性高,选择性好,可循环使用多次反应循环。