Syntheses, structures and magnetic properties of two unprecedented hybrid compounds constructed from open Wells-Dawson anions and high-nuclear transition metal clusters

摘要

Two new inorganic-organic hybrid compounds Na_2(C _3N_2H_(12))_4{[Ni_5(OH) _3(H_2O)_4(CH_3CO_2)][Si _2W_(18)O_(66)]}·12.5H_2O (1) and (C_3N_2H_(12))_3{[CoII _2Co~(III) _4(OH)_5(H_2O) _2(CH_3CO_2)][Si_2W_(18)O _(66)]}·6H_2O·(C_3N_2H _(10)) (2), based on lacunary polyoxometalates and high-nuclear transition-metal clusters, have been synthesized by a new method (solvothermal method). Single crystal XRD, magnetic measurements, nonlinear-optical (NLO) measurements, thermogravimetric (TG) measurements, and IR spectra were performed to analyze the structures and properties of 1 and 2. XRD analyses reveal that compound 1 consists of an open Wells-Dawson anion [Si_2W _(18)O_(66)]~(16-), a five-nuclear cationic cluster [Ni_5(OH)_3(H_2O)_4(CH _3CO_2)]~(6+), free Na~+ cations, and protonated 1,3-diaminopropanes. Compound 2 has a similar structure to 1, while a six-nuclear cationic cluster [Co~(II))2Co~(III) _4(OH)_5(H_2O)_2(CH_3CO _2)]~(10+) replaces the five-nuclear cationic cluster [Ni _5(OH)_3(H_2O)_4(CH_3CO _2)]~(6+) in 1. Magnetic susceptibility measurements indicate antiferromagnetic interactions in 1, and the chirality of compound 2 may bring potential properties of catalysis and optical nonlinearity.