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

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 [Ce2(bpm)(dmf)6(H2O)8][W(CN)8]2·3H2O (1; dmf = N,N-dimethylformamide), tetranuclear molecules [Ce2(bpm)(dmso)8(H2O)4][W(CN)8]2·4H2O (2; dmso = dimethyl sulfoxide), and a two-dimensional inorganic−organic hybrid coordination polymer {[Ce2(bpm)(dmf)8(H2O)2][W(CN)8]2}n·2nH2O (3), all of which contain the subunit [Ce2(μ-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 JCeW = 1.7 (2) and 1.4(3) cm−1 (3) compared to the antiferromagnetic {Ce−bpm−Ce} interaction JCeCe = −1.1 cm−1 (1 and 2).