Two novel azido-copper(II) complexes with 4-(1H-tetrazol-1-yl) carboxylate: Synthesis, crystal structure, and magnetism

•Two novel azido-copper(II) complexes have been synthesized and investigated.•Interesting structure-tuning of the two complexes has been discussed.•Both the complexes exhibit preferable ferromagnetism.

Using same reactants with different mol ratio, two novel azido-copper(II) compounds [Cu(L)(N3)]n (1) and {[Cu3(L)2(N3)4](CH3OH)3}n (2) {HL=4-(1H-tetrazol-1-yl) benzoic acid} have been synthesized by the method of liquid diffusion at room temperature and structurally characterized. Single crystal X-ray diffraction analyses show that complex 1 has a two dimensional (2D) coordination structure with carboxylate/EO (end on)-azido mixed-bridged copper(II) chains, while 2 possesses different Cu−N3−/COO−Cu−N3−/COO− one dimensional (1D) chains from that of 1, with double EE (end to end) azido bridge and carboxylate/EO-azido mixed-bridge coexisting, forming a 2D supramolecular framework by interchain H-bonds. The structural difference between 1 and 2 suggests that the tetrazolyl motif also has important influence on the construction of these complexes. Magnetic study indicates that domain ferromagnetic coupling interactions exist in both 1 and 2.

Graphical abstractTwo novel azido-copper complexes were synthesized by liquid diffusion at room temperature. The structural characterization and magnetic study of these compounds exhibit interesting structure-tuning and fine-tuning of magnetism.Figure optionsDownload full-size imageDownload as PowerPoint slide