new calixarene-supported CoII9 clusters housing a μ9-CO32- anion

Calix[4]arene-Based Clusters with μ9-Carbonato-Bridged CoII9 Cores

Kongzhao Su, Feilong Jiang, Jinjie Qian, Kang Zhou, Jiandong Pang, Sulaiman Basahel, Mohamed Mokhtar, Shaeel A. AL-Thabaiti, Maochun Hong

Abstract


Two discrete complexes, [CoII9(TBC[4])3(m9-CO3)(m-H2O)3(m3-OH)2(m-CH3COO)2(DMA)4]•3H2O•2CH3OH (1), [CoII9(TBC[4])3(m9-CO3)(m3-OH)(m-HCOO)(O3PPh)(DMF)8]•2H2O•CH3OH (2) (TBC[4] = p-tert-butylcalix[4]arene, DMA = N,N'-dimethylacetamide, DMF = N,N'-dimethylformamide), have been solvothermally obtained and structurally characterized by single-crystal X-ray diffraction analyses and powder X-ray diffraction. Complex 1 capped by three TBC[4] ligands possesses a tri-capped trigonal prismatic CoII9 core housing a m9-carbonato anion. When auxiliary phosphonate ligand is introduced into the reaction, complex 2 is obtained with an obvious geometrical change in the metallic core moving from a regular tri-capped trigonal prism in 1 to a distorted one in 2. What is more, this work represents the first two examples of m9-CO32- bridged paramagnetic metal clusters reported in the literature. Magnetic measurements reveal that both of the complexes show spin-glass behavior.


Keywords


Calix[4]arene; Cluster; Magnetism; Spin-glass

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