Crystalline Cu(ii) metal-organic frameworks based on a carboxamide pincer ligand and an N^CON^CON-Pd(ii) pincer complex

Two new metal-organic frameworks (MOFs) with copper(ii) paddlewheel secondary building units are presented.Cu-MOFandPd@Cu-MOFwere prepared in open air at room temperature from a pincer ligand 4,4′-((pyridine-2,6-dicarbonyl)bis(azanediyl))dibenzoic acid (L1) and a pincer complex N^CON^CON-Pd(ii) (C1), respectively. The two crystalline 2-D frameworksPd@Cu-MOFandCu-MOFwere characterized as microporous materials with Brunauer-Emmett-Teller (BET) surface areas of 12 m²g⁻¹and 33 m²g⁻¹, respectively. Gas adsorption experiments revealed a low uptake of carbon dioxide by these materials attributed to crystal-to-crystal transformation of the MOFs upon activation.