Su-Ling Xu

Synthesis, crystal structure and thermal decomposition mechanism of a samarium o-chlorobenzoate complex with 1,10-phenanthroline

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) A, b = 14.139(4) A, c = 17.397(4) A, a = 83.755(3)o, b = 84.064(3)o, g =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 Kissingers method and Ozawa-Doyles method. The lifetime equation at weight-loss of 10% was deduced as lnt= 26.8166+20319.94/T by isothermal thermogravimetric analysis.

Lanthanide complexes with 3,4,5-triethoxybenzoic acid and 1,10-phenanthroline: synthesis, crystal structures, thermal decomposition mechanism and phase transformation kinetics

Three novel lanthanide complexes [Ln(3,4,5-TEOBA)3phen]2 (Ln = La(1), Pr(2), Eu(3); 3,4,5-TEOBA = 3,4,5-triethoxybenzoate; phen = 1,10-phenanthroline) were synthesized and characterized. Single crystal X-ray diffraction showed that the complexes are isostructural. Each complex has two center metals and each center is coordinated with seven oxygen atoms and two nitrogen atoms to form a distorted monocapped square antiprism geometry. A carboxylic group adopts three modes coordinated with center metal: bidentate chelate, bridging bidentate and bridging tridentate. The luminescence of complex 3 showed the characteristic emission of Eu3+ (5D0 → 7F0–3). The thermal decomposition mechanism of title complexes was studied by TG/DSC-FTIR technology. The heat capacities of complexes 1–3 were measured by DSC over the temperature range from 263.15 to 463.15 K. In the temperature range from 280 to 350 K, there was a solid-to-solid phase transition for each complex, which was further evidenced by four thermal circulating processes with the scanning rate of 10 K min−1. A study of the phase transition of four thermal circulating processes under different heating rates revealed a fine linear relationship between the activation energy (E) and the percent conversion (α). In the heating and cooling runs, supercooling was observed and the endothermic and exothermic enthalpies behaved differently.

Preparation, crystal structure and mechanism of thermal decomposition of complex [Dy(p-MOBA)3Phen]2

Abstract1,10-Phenanthrolinetris(4-methoxybenzoate)dysprosium, Dy(p-MOBA)3Phen (where p-MOBA = p-methoxybenzoate and Phen = 1,10-phenanthroline), (I) has been synthesized. The complex was characterized by various techniques including elemental analysis, UV, IR, XRD, molar conductance, and TG-DTG. The crystals consist of binuclear molecules and monoclinic, space group P21/n: a = 14.143(6) Å, b = 17.550(7) Å, c = 14.493(6) Å, β = 117.357(4)°, Z = 2, ρc = 1.655 g cm−3, F(000) = 1588; R1 = 0.0176, wR2 = 0.0455. In the complex, each Dy3+ ion is nine-coordinate to one 1,10-phenanthroline molecule, one bidentate chelating carboxylate group, and four bridging carboxylate groups in which the carboxylate groups are bonded to the Dy3+ ions in three modes: bridging bidentate, bridging tridentate, and chelating bidentate. The thermal decomposition mechanism of I has been determined on the basis of thermal analysis. In addition, the lifetime equation at a weight-loss of 10% was deduced as lnτ = −28.8361 + 19478.37/T by isothermal thermogravimetric analysis.

Synthesis, Crystal Structure and Thermal Decomposition Mechanism of a Dysprosium(III) p-Fluorobenzoate 1,10-Phenanthroline Complex

A dinuclear dysprosium(III) p-fluorobenzoate 1,10-phenanthroline complex, [Dy(p-FBA)3phen]2 was synthesized and characterized by elemental analysis, UV and IR spectroscopy, single crystal X-ray diffraction, molar conductance, and TG-DTG techniques. It crystallizes in the triclinic space group P1̄ with a = 9.895(5), b = 11.754(6), c = 14.756(10)Å ; α = 106.660(9)°, β = 107.956(9)°, γ =101.472(7)°; Z =1. The Dy(III) ions are eight coordinate including one terminal bidentate chelating carboxylate group, four bridging carboxylate groups and one 1,10-phenanthroline molecule. The thermal decomposition of [Dy(p-FBA)3phen]2 has been followed by thermal analysis. The lifetime equation at weight-loss of 10% was deduced as lnτ = −27.0798 +19010.2434/T by isothermal thermogravimetric analysis.

Synthesis and crystal structure of the complex [Sm(p-MOBA)3bipy]2 · 2C2H5OH

AbstractA new binuclear complex [Sm(p-MOBA)3bipy]2 · 2C2H5OH (p-MOBA = p-methoxybenzoate, bipy = 2,2′-bipyridine) has been prepared via dissolution reaction in an ethanol/water mixed solution and characterized by elemental analysis, IR, UV, XRD and molar conductance, respectively. Its single crystal was characterized by X-ray single crystal diffraction. The crystal belongs to triclinic system, space group P

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

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Synthesis, crystal structure and thermal decomposition mechanism of the complex [Sm(p-BrBA)3bipy·H2O]2·H2O

. The crystallographic data are: a = 10.970(3) Å, b = 11.507(4) Å, c = 13.931(4) Å, α = 84.449(4)°, β = 76.403(4)°, γ = 87.284(4)°, Z = 1, Dr = 1.574 Mg/m3, FW = 1612.02, F(000) = 814, R1 = 0.0275, wR2 = 0.0646. Two Sm3+ ions are linked by four carboxylic groups with bidentate bridging and tridentate chelating-bridging coordination modes. Each center Sm3+ is nine coordinated with a distorted tri-capped triangular prism geometry.

A series of binuclear lanthanide(III) complexes: Crystallography, antimicrobial activity and thermochemistry properties studies

Abstract(1.10-Phenanthroline)-tris(4-amidobenzoate)dysprosium, [Dy(p-ABA)3Phen · H2O] · 1.5H2O (where p-ABA = p-amidobenzoate and Phen = 1.10-phenanthroline) has been synthesized. The complex was characterized by elemental analysis, UV, IR spectroscopy, and molar conductance. The crystal structure was determined by X-ray crystallography. The coordination number of the mononuclear complex is nine. The crystals are triclinic, space group P1 with a = 10.4484(13) Å, b = 12.2015(15) Å, c = 14.0170(17) Å; α = 92.800(2)°, β = 102.7220(10)°, γ = 108.880(2)°. Z = 2, dc = 1.617 mg m−3, F(000) = 786. R1 = 0.0327, and wR2 = 0.0911.