Synthesis, characterization and magnetic properties of four new organically templated metal sulfates [C5H14N2][M-II(H2O)(6)](SO4)(2), (M-II = Mn, Fe, Co, Ni)

A series of novel organically templated metal sulfates, [C5H14N2][M-II(H2O)(6)](SO4)(2) with (M-II = Mn(1), Fe (2), Co (3) and Ni (4)), have been successfully synthesized by slow evaporation and characterized by single-crystal X-ray diffraction as well as with infrared spectroscopy, thermogravimetric analysis and magnetic measurements. All compounds were prepared using a racemic source of the 2-methylpiperazine and they crystallized in the monoclinic systems, P2(1)/n for (1, 3) and P2(1)/c for (2,4). Crystal data are as follows: [C5H14N2][Mn(H2O)(6)](SO4)(2), a = 6.6385(10) angstrom, b = 11.0448(2) angstrom, c = 12.6418(2) angstrom, beta = 101.903(10)degrees, V = 906.98(3) angstrom(3), Z = 2; [C5H14N2][Fe(H2O)(6)](SO4)(2), a = 10.9273(2) angstrom, b = 7.8620(10) angstrom, c = 11.7845(3) angstrom, beta = 116.733(10)degrees, V = 904.20(3) angstrom(3), Z = 2; [C5H14N2][Co(H2O)(6)](SO4)(2), a = 6.5710(2) angstrom, b = 10.9078(3) angstrom, c = 12.5518(3) angstrom, beta = 101.547(2)degrees, V = 881.44(4) angstrom(3), Z = 2; [C5H14N2] [Ni(H2O)(6)]-(SO4)(2), a = 10.8328(2) angstrom, b = 7.8443(10) angstrom, c = 11.6790(2) angstrom, beta = 116.826(10)degrees, V = 885.63(2) angstrom(3), Z = 2. The three-dimensional structure networks for these compounds consist of isolated [M-II(H2O)(6)](2+) and [C5H14N2](2+) cations and (SO4)(2-) anions linked by hydrogen-bonds only. The use of racemic 2-methylpiperazine results in crystallographic disorder of the amines and creation of inversion centers. The magnetic measurements indicate that the Mn complex (1) is paramagnetic, while compounds 2, 3 and 4, (M-II = Fe, Co, Ni respectively) exhibit single ion anisotropy.