Maleates of Mn(II), Fe(II), Co(II), and Ni(II) as precursors for synthesis of metal-polymer composites

Comparison was made for the structural, IR spectral, and thermoanalytical characteristics of normal [M-1(H2O)(2)(C4H2O4)](H2O) (M-1 = Co(II) and Ni(II)) and acid maleates [M-2(H2O)(4)(C4H3O4)(2)] (M-2 = Mn(II), Fe(II), Co(II) and Ni(II)). Only structures of acid maleates contain intramolecular asymmetric hydrogen bond whose asymmetry increases in the series of transition metal salts. Thermal decomposition of Co(II), Ni(II) normal maleates, and Mn(II), Fe(II), Co(II), Ni(II) acid maleates proceeds in three stages. Onset decomposition temperatures for the first and second stages decreases in the series of normal maleates Co(II) a parts per thousand yen Ni(II) and increases in the series of acid maleates Fe(II) < Co(II) < Ni(II) a parts per thousand Mn(II). Onset temperature of the third stage decreases in the series of both normal maleates Co(II) > Ni(II) and acid maleates Mn(II) > Fe(II) > Co(II) > Ni(II).