Formation and magnetic property of an octanuclear metallamacrocycle-based three-dimensional metal organic framework

In this article, a chiral azolate-based octanuclear metallamacrocycle three-dimensional (3D) complexes {[Co2(pbt)2(H2O)2] · 4.5H2O}n (1) have been synthesized and characterized. Complex 1 crystallizes in the space group P43212 and displays a complicate homochiral three-dimensional (3D) framework containing octanuclear cobalt metallamacrocycles. The trizole-N1, N2 bridging cobalt trinuclear secondary building units (SBUs) in complex 1 provides a platform to investigate the magneto-structural correlations. The weak magnetic exchange of this complex is due to the asymmetric doubly 1,2,4-triazole-N1,N2 bridged SBUs which reduces the ineffective overlap between the orbits of paramagnetic central ions.