The complex [Ho(BA)3bipy]2 (BA=benzoate; bipy=2,2'-bipyridine) was synthesized and characterized by elemental analysis, infrared spectra, ultraviolet spectra, single-crystal X-ray diffraction, thermogravimetry and differential thermogravimetry (TG-DTG) techniques. The crystal is monoclinic with space group P2/n. The unit cell parameters are: a=14.1114(8) Å, b=15.3743(9) Å, c=25.8887(14) Å, β=103.555(2)°. Two Ho3+ ions are connected by four carboxylic groups through a bridging bidentate mode. The thermal decomposition behavior of the title complex under nitrogenous atmosphere was studied using the TG-DTG, and IR techniques. The non-isothermal kinetics was investigated by using the Popescu method and the integral iso-conversional non-linear method (NL-INT). The mechanism function of the first decomposition step was determined. The thermodynamic parameters (ΔG≠, ΔH≠ and ΔS≠) were also calculated, and kinetic parameters (activation energy E and the pre-exponential factor A) were also obtained.

A dinuclear complex [Dy(m-MBA)3phen]2-H2O was prepared by the reaction of DyCl3-6H2O, m-methylbenzoic acid and 1,10-phenanthroline in a 1:3:1 molar ratio, where m-MBA = m-methylbenzoate and phen = 1,10-phenanthroline. The complex was structurally characterized by single crystal X-ray diffraction, elemental analysis, UV and IR spectroscopy, molar conductance and TG-DTG techniques. It crystallizes in the monoclinic space group Cc with a =15.962(16), b = 18.505(18), c = 22.547(2) Ǻ; a = 90 °, β = 97.9820(10) °, y = 90°; z = 4. The unit cell contains a dinuclear molecule of the title compound. Each Dy(III) ion is eight-coordinated to one 1,10-phenanthroline molecule, one bidentate carboxylate group and four bridging carboxylate groups. The carboxylate groups are bonded to the dysprosium ions in two modes: chelating bidentate and bridging bidentate. The thermal decomposition process of [Dy(m-MBA)3phen]2-H2O has been followed by thermal analysis.

O complexo [Sm(oClBA)3phen]2 (oClBA= o-clorobenzoato; phen= 1,10-fenantrolina) foi preparado pela reação de SmCl3·6H2O com ácido o-clorobenzóico e 1,10-fenantrolina. O complexo foi caracterizado por um estudo de difração de raios-X, análise elementar, espectroscopia no infravermelho e técnicas TG-DTG. O cristal é triclínico, grupo espacial P I com a = 13,157(3) Å, b = 14,139(4) Å, c = 17,397(4) Å, alfa = 83,755(3)º, beta = 84,064(3)º, gama = 73,434(3)º, Z=2, Dc=1,722 Mg/m³, F(000)=1572. Contém duas unidades cristalograficamente distintas de Sm(o-ClC6H4COO)3(C12H 8N2), formando dois tipos de moléculas binucleares. Cada Sm3+ encontra-se coordenado a dois átomos de oxigênio de um grupo carboxilato bidentado quelante, cinco átomos de oxigênio de dois grupos carboxilatos bidentados ligados em ponte e de três grupos carboxilatos tridentados quelantes e ligados em ponte, e a dois átomos de nitrogênio de uma molécula de 1,10-fenantrolina, completando uma geometria monoencampuzada antiprismática quadrada. A decomposição térmica deste composto foi estudada por técnicas TG-DTG, e os parâmetros cinéticos da primeira etapa da decomposição foram determinados pelos métodos de Kissinger e Ozawa-Doyle. A equação de meia vida após 10% de perda de peso, lntau= 26,8166+20319,94/T, foi deduzida por análise termogravimétrica da isoterma.

The title complex [Sm(oClBA)3phen]2 (oClBA= o-chlorobenzoate; phen= 1,10-phenanthroline) was prepared by the reaction of SmCl3·6H2O, o-chlorobenzoic acid and 1,10-phenanthroline. The complex was 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 I with a = 13.157(3) Å, b = 14.139(4) Å, c = 17.397(4) Å, alpha = 83.755(3)º, beta = 84.064(3)º, gamma =73.434(3)º, Z=2, Dc=1.722 Mg/m³, F(000)=1572. The crystal contains two crystallographically distinct Sm(o-ClC6H4COO)3(C12H 8N2) units, forming two types of binuclear molecule. Each Sm3+ is coordinated to two O atoms of one bidentate chelating carboxylate group, five O atoms of two bidentate bridging and two tridentate chelating-bridging carboxylate groups, and two N atoms of one 1,10-phenanthroline molecule to complete a distorted mono-capped square antiprism geometry. Its thermal decomposition mechanism was determined by TG-DTG techniques, and kinetic parameters have been studied on the first-step decomposition of [Sm(oClBA)3phen]2 by means of Kissinger's method and Ozawa-Doyle's method. The lifetime equation at weight-loss of 10% was deduced as lntau= 26.8166+20319.94/T by isothermal thermogravimetric analysis.