Magnetic Properties versus Network Dimensionality of Cerium(III) Octacyanotungstate(V) Compounds

Abstract

The reaction of cerium(III) nitrate, sodium octacyanotungstate(V), and 2,2'-bipyrimidine (bpm) under various conditions leads to the formation of three new compounds: ionic [Ce(2)(bpm)(dmf)(6)(H(2)O)(8)][W(CN)(8)](2).3H(2)O (1; dmf = N,N-dimethylformamide), tetranuclear molecules [Ce(2)(bpm)(dmso)(8)(H(2)O)(4)][W(CN)(8)](2).4H(2)O (2; dmso = dimethyl sulfoxide), and a two-dimensional inorganic-organic hybrid coordination polymer {[Ce(2)(bpm)(dmf)(8)(H(2)O)(2)][W(CN)(8)](2)}(n).2nH(2)O (3), all of which contain the subunit [Ce(2)(mu-bpm)] within the structure. These systems were characterized by single-crystal X-ray diffractometry, FTIR spectroscopy, and thermogravimetric analysis. Magnetic susceptibility measurements for 1-3 were performed on polycrystalline samples of the compounds. Magnetic behavior was interpreted in terms of the ligand-field splitting parameters and the exchange interaction between lanthanide centers and a d-electron spin carrier. The results confirmed the ferromagnetic cyano-mediated {Ce-NC-W} interaction J(CeW) = 1.7 (2) and 1.4(3) cm(-1) (3) compared to the antiferromagnetic {Ce-bpm-Ce} interaction J(CeCe) = -1.1 cm(-1) (1 and 2).