Synthesis and structural characterization of different topological coordination polymers based on tunable Cu4Br4-mIm secondary building units and macrocyclic azacalixaromatics

The coordination self-assembly between the macrocyclic ligand tetraazacalix[4]pyrimidine (TAPM) with cubane-like copper halides (Cu4X4) produced five coordination polymers 1-5 {Cu4Br4-mIm(TAPM)}(n) (m = 0 (1), 1(2), 2 (3), 3 (4) and 4 (5)). X-ray single crystal analysis revealed that the Br:I ratio in the Cu4X4 cores serves as a controlling factor to fine-tune the geometries of Cu4X4 and therefore induce the conformation variation of tetraazacalix[4]pyrimidine. Consequently, two different topological nets, dia and lcs, were successfully constructed based on tetrahedrally coordinated Cu4X4 secondary building units and the flexible macrocyclic quadridentate ligand TAPM. The structure details of 1-5 as porous materials are analyzed, which shows a solvent accessible volume within the range of 27-35%. Compounds 1-5 exhibit luminescence properties with the peak maximum at around 476-488 nm. (c) 2010 Elsevier Inc. All rights reserved.