Synthesis, crystal structure and thermal decomposition mechanism of complex [Sm(o-MBA)3phen]2

The title complex [Sm(o-MBA)3phen]2 (o-MBA, o-methylbenzoate; phen, 1,10-phenanthroline) was prepared and characterized by single crystal X-ray diffraction, elemental analysis, IR spectra and TG-DTG techniques. The results show that the crystal is triclinic, space group P ī with a = 13.1364(10) Å, b = 14.3739(11) Å, c = 17.4356(13) Å; α = 83.1100(10)°, β = 83.7760(10)°, γ = 73.0520(10)°, Z = 2, Dc = 1.568 Mg/m3, F (000) = 1476. The crystal is consisted of two similar types of binuclear molecule. Each Sm3+ is nine-coordinated by one bidentate chelating carboxylate group, two bidentate bridging and two tridentate chelating-bridging carboxylate groups, as well as one 1,10-phenanthroline molecule. The thermal decomposition mechanism of [Sm(o-MBA)3phen]2 has been determined on the basis of thermal analysis. The dependences of E −α for the first-stage decomposition process were determined by using Ozawa-iterative procedure, which show the E values varied with the extent of conversion. In addition, the lifetime equation at weight-loss of 10% was deduced as ln τ = −25.5547 + 18511.68/T by isothermal thermogravimetric analysis.