Hits:

Indexed by:期刊论文

Date of Publication:2017-03-28

Journal:DALTON TRANSACTIONS

Included Journals:SCIE、EI、PubMed

Volume:46

Issue:12

Page Number:4086-4092

ISSN No.:1477-9226

Abstract:A discrete tetranuclear thiourea-based metal-organic macrocycle (MOM) with a large size was constructed by a well-designed organic ligand and nickel(II) ions via self-assembly. Incorporating thiourea groups as hydrogen-bond donors into a metal-organic complex system leads to a new approach for synthesizing functionalized heterogeneous catalysts, as this not only introduces coordination sites serving as chelators, but also overcomes the issues of self-association via intermolecular H-bonding, often occurring in homogeneous systems. The packing structure of this material formed a confined environment suitable for the access of substrate molecules dragged by the strong hydrogen-bond interactions from the thiourea groups, thus achieving a high catalytic performance in Michael additions of nitrostyrenes to nitroalkanes, with remarkable yields and size-selectivity in heterogeneous phase. Moreover, a comparison of the IR spectrum of Ni-SPT with the spectra of dimethyl malonate-and beta-nitrostyreneimpregnated Ni-SPT indicated that both substrate molecules, beta-nitrostyrene and dimethyl malonate, were able to access the cavity of the trimeric subunit.