Synthesis of a NbO Type Homochiral Cu(II) Metal–Organic Framework: Ferroelectric Behavior and Heterogeneous Catalysis of Three-Component Coupling and Pechmann Reactions
作者:Anoop K. Gupta、Dinesh De、Rajesh Katoch、Ashish Garg、Parimal K. Bharadwaj
DOI:10.1021/acs.inorgchem.7b00342
日期:2017.4.17
A chiral tetracarboxylic acid ligand, H4L, incorporating the (S)-(+)-2-methylpiperazine moiety in its middle, solvothermally forms a homochiral Cu(II) framework, [Cu2(L)(H2O)2]·(4DMF)(4H2O)}n (LCu). It forms a non-interpenetrated structure consisting of [Cu2(COO)4] paddle-wheel secondary bonding units (SBUs) with NbO topology. Interestingly, the framework LCu exhibits excellent ferroelectric properties
在其中间结合有(S)-(+)-2-甲基哌嗪部分的手性四羧酸配体H 4 L溶剂热形成均手性Cu(II)骨架,[Cu 2(L)(H 2 O)2 ]·(4DMF)(4H 2 O)} n(LCu)。它形成了一个由NbO拓扑结构的[Cu 2(COO)4 ]桨轮辅助键合单元(SBU)组成的非互穿结构。有趣的是,框架LCu具有出色的铁电性能。它显示出残留的极化(Pr)约为3.5μCcm –2矫顽场(E c)约为12 kV cm –1,具有明显的电滞回线。对LCu的介电研究表明,在频率高达10 6 Hz的情况下,其介电常数(εr)约为42,低介电损耗(tanδ)约为0.04,而与频率无关。另外,具有未配位金属位点的活化骨架LCu'在胺,醛和炔的三组分偶联中以及在酚与β-酮酸酯的Pechmann反应中充当有效的多相催化剂。