Effects of organic templates on directing the structures of nickel(II)-1-hydroxyethylidenediphosphonate compounds: A structural and magnetic study

Hydrothermal reactions of NiSO4 and 1-hydroxyethylidenediphosphonic acid (hedpH(4)) in the presence of different organic templates resulted in the formation of three new compounds: (enH(2))Ni(hedpH(2))(2). 2H(2)O 1, (pnH(2))Ni(hedpH(2))(2)(H2O), 2 and (bnH(2))Ni(hedpH(2))(2)(H2O)(2), 3, (hedp = 1-hydroxyethylidenediphosphonate, en = ethylenediamine, pn = 1,3-propanediamine, bn = 1,4-butylenediamine). Crystal data: 1, monoclinic, C2/c, a = 24.7864(5),b = 5.2565(1), c = 16.0468(2) Angstrom, beta = 117.903(1)degrees, V=1847.67(6) Angstrom(3), Z = 4; 2, triclinic, P (1) over bar, a = 10,0926(4), b = 10.5621(4), c = 10.9212(4) Angstrom, alpha = 111.520(1), beta = 110.833(1), gamma = 93.630(1)degrees, V = 986.77(7) Angstrom(3), Z = 2; 3, monoclinic, C2/c, a = 16.230(2), b = 12.430(13), c = 12.657(13) Angstrom, beta = 121.997(10)degrees, V = 2165(4) Angstrom(3), Z = 4. The compound 1 has a one-dimensional chain structure which is composed of corner-sharing (NiO6) octahedra and (O3PC) tetrahedra with the ethylenediammonium cations and water molecules stabilized between the chains. By replacing ethylenediamine with 1,3-propanediamine or 1,4-butylenediamine, molecular species have been obtained. The compound 2 contains dimers of [Ni(hedpH(2))(2)(H2O)](2)(2-) whereas 3 is a mononuclear compound. The thermal stabilities, spectroscopic and magnetic properties of all three compounds have been investigated.