Inhibition, Binding of Organometallics, and Thermally Induced CO Release in an MFU-4-Type Metal-Organic Framework Scaffold with Open Bidentate Bibenzimidazole Coordination Sites.

Abstract

Triazolate-based MFU-4-type metal-organic frameworks are promising candidates for various applications, of which heterogeneous catalysis has emerged as a hot topic owing to the facile post-synthetic metal and ligand exchange in Kuratowski secondary building units (SBUs). Herein, we present the largest non-interpenetrated isoreticular MFU-4-type framework CFA-19 ([Co5IICl4(H2-bibt)3]; H4-bibt = 1,1',5,5'-tetrahydro-6,6'-biimidazo[4,5-f]benzotriazole; CFA-19 = Coordination Framework Augsburg University-19) and the CFA-19-Tp derivative featuring trispyrazolylborate inhibited SBUs as a scaffold with open bibenzimidazole coordination sites at the backbone of the H4-bibt linker. The proof-of-principle incorporation of accessible MIBr(CO)3 (M = Re, Mn) sites in CFA-19-Tp was revealed by single-crystal X-ray diffraction, and a thermally induced CO release was observed for MnBr(CO)3. Deprotonation of bibenzimidazole was also achieved by the reaction with ZnEt2.