A Multifunctional Nanocage-based MOF with Tri- and Tetranuclear Zinc Cluster Secondary Building Units

Abstract

A new Zn-cluster based MOF, [Zn21(BTC)11(μ3-OH)3(μ4-O)3(H2O)18]·21EtOH (1) (H3BTC = 1,3,5-benzenetricarboxylic acid), with two different types of cluster nodes has been successfully synthesized from Zn2+ and H3BTC under the solvothermal conditions. Single crystal X-ray diffraction studies reveal that 1 is a 3D trinodal (3,5,6)-c framework which features a large octahedral cage organized by nine Zn3O and nine Zn4O clusters SBUs and twenty-four triangular BTC3- linkers. The Eu3+/Tb3+-incorporated derivative of 1 with 0.251% Eu3+ and 0.269% Tb3+ exhibits tunable luminescence from yellow to white and then to blue-green by changing the excitation wavelength from 308 to 315 nm. Metal ion exchange with Cu2+ affords isomorphous Cu-based MOF with enhanced N2 and CO2 adsorption capacity. In addition, 1 can act as a selective luminescent sensor for Cu2+ and Al3+ ions.