Several analytical instruments (like pyrolyzers, thermobalances, differential thermal analyzers, or calorimeters, and sometimes simply temperature-controlled reactors) can be on-line coupled to infrared spectrometers to perform evolved gas analysis (EGA). Advances in EGA techniques are currently proposed by the scientific literature because the possibility to on-line detect the nature of the released gases or vapors has become fundamental to proving a supposed reaction, either under isothermal or under heating conditions. In this review, recent analytical applications of evolved gas analysis performed by infrared spectroscopy (EGA-IR), selected among those published in the years 2013 to 2015, are collected.

FTIR-evolved gas analysis in recent thermoanalytical investigations

Two novel lanthanide metal–organic frameworks (Ln-MOFs), formulated as {[Ln2(L2)2(H2O)5]•3H2O}n (Nd 1 and Eu 2) has been acquired under hydrothermal conditions, in which H3L2 ligand was derived fro...

Two novel lanthanide metal–organic frameworks: selective luminescent sensing for nitrobenzene, Cu2+ and MnO4-

Nowadays, it is still a great challenge for lanthanide complexes to be applied in solid state lighting, especially for high-power LEDs because they will suffer severe thermal-induced luminescence quenching and transmittance loss when LEDs are operated at high current. In this paper, we have not only obtained high efficient and thermally chemical stable red emitting hybrid material by introducing europium complex into nanozeolite (NZ) functionalized with the imidazolium-based stopper but also abated its thermal-induced transmittance loss and luminescence quenching behavior via coating it onto a heat-resistant luminescent glass (LG) with high thermal conductivity (1.07 W/mK). The results show that the intensity at 400 K for Eu(PPO)n-C4Si@NZ@LG remains 21.48% of the initial intensity at 300 K, which is virtually 153 and 13 times the intensity of Eu(PPO)3·2H2O and Eu(PPO)n-C4Si@NZ, respectively. Moreover, an organic-resin-free warm white LEDs device with a low CCT of 3994K, a high Ra of 90.2 and R9 of 57.9 wa...

Thermally Stable White Emitting Eu3+ Complex@Nanozeolite@Luminescent Glass Composite with High CRI for Organic-Resin-Free Warm White LEDs

Four novel lanthanide complexes, [Ln(2,4-DClBA)3(terpy)(H2O)]·H2O (Ln = Eu(1), Tb(2)); [Ln(2,4-DClBA)3(5,5′-DM-2,2′-bipy)(C2H5OH)]2 (Ln = Eu(3), Tb(4); 2,4-DClBA: 2,4-dichlorobenzoate; terpy: 2,2′:6′,2′′-terpyridine; 5,5′-DM-2,2′-bipy: 5,5′-dimethyl-2,2′-bipyridine) have been synthesized via a conventional solution method at room temperature and structurally characterized by single crystal and powder X-ray diffraction. Complexes 1–2 exhibit mononuclear lanthanide architectures and each Ln3+ ion is nine-coordinated adopting a distorted monocapped square antiprismatic molecular geometry, while complexes 3–4 exhibit binuclear lanthanide architectures in which each Ln3+ ion is eight-coordinated adopting a distorted square antiprismatic molecular geometry. Mononuclear complexes 1–2 are stitched together via Cl–π and hydrogen bonding interactions to form the 1D, 2D, 3D supramolecular structures. While complexes 3–4 are packed together through Cl–Cl, π–π, and hydrogen bonding interactions to form 1D, 2D supramolecular structures. Luminescence investigation reveals that complexes 1, 3 and 2, 4 display strong red and green emission respectively, showing that terpy and 5,5′-DM-2,2′-bipy can act as sensitizing chromophores, but the former is more effective. The IR, TG-DTG, and the heat capacities of complexes 1–4 were also measured.

A series of lanthanide complexes with different N-donor ligands: synthesis, structures, thermal properties and luminescence behaviors

The new hexadentate N2O4 Schiff base ligand from condensation of 2,4-hydroxybenzophenone and 1,3-propanediamine has been prepared in methanol and ethanol solutions. The Schiff base synthesized from EtOH contains half molecule of amine per one molecule of ligand in its structure. The complexes were synthesized from the direct reaction of this ligand and Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) acetates. The Schiff base and its complexes were characterized by elemental analysis, X-ray crystallographic techniques, spectroscopic (UV–Vis, IR) and thermal (TG, TG-FTIR) methods, molar conductance and magnetic measurements. The complexes, except for Ni(II) compound, similar to the Schiff base are amorphous solids. The Ni(II) complex crystallizes in the monoclinic space group P21/c. The N2O2 coordination geometry around nickel(II) is slightly tetrahedrally distorted square planar. Variable temperature magnetic studies of the paramagnetic complexes show the existence of weak antiferromagnetic [for complexes of manganese(III) and cobalt(II)] and weak ferromagnetic [for copper(II)] interactions. The complexes are stable at ambient temperature. After heating at first they lose solvent molecules (water or methanol), and after that organic part undergoes defragmentation and combustion. Based on the obtained data from the TG-FTIR analysis, the main gaseous products resulting from thermal degradation in nitrogen atmosphere are CO2, CO, NH3, acetic acid, methane, C6H6, C6H5CN and C6H5CH3.

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Synthesis, thermal study and some properties of N2O4—donor Schiff base and its Mn(III), Co(II), Ni(II), Cu(II) and Zn(II) complexes

Four dinuclear trivalent lanthanide complexes of the general formula [Ln2(2-Br-5-MOBA)6(phen)2] (Ln = Nd(), Sm(), Ho(), Er(); 2-Br-5-MOBA = 2-bromine-5-methoxybenzoate, phen = 1,10-phenanthroline) were prepared and structurally characterized. The complexes to are isostructural with a coordination number of nine. The carboxylic acid ligands adopt bridging, bidentate chelating, and tridentate chelating bridging modes to coordinate with Ln(iii) ions. The structures of the complexes were confirmed on the basis of elemental analysis, molar conductance, thermogravimetric analysis (TGA), and IR and UV spectra. The heat capacities and thermal circulating processes of the prepared complexes were performed on a differential scanning calorimeter under a nitrogen atmosphere. Two remarkable solid-solid phase transitions existed both in the heat capacities and thermal circulating processes. The bacteriostatic activities of the complexes were evaluated against Candida albicans, Escherichia coli and Staphylococcus aureus. Besides, the luminescent property of complex was also investigated, and the magnetic properties of complexes and were also discussed in detail.

Preparation, characterization and properties of four new trivalent lanthanide complexes constructed using 2-bromine-5-methoxybenzoic acid and 1,10-phenanthroline.

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.

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

Novel lanthanide complexes constructed from 3, 4-dimethoxybenzoic acid: crystal structures, spectrum and thermochemical properties

The crystal structures of complexes [Tb(3-Br-4-MBA)3phen]2(1), [Ho(3-Br-4-MBA)3(phen)H2O]2(2) and [Er(3-Br-4-MBA)3(phen)H2O]2(3) (3-Br-4-MBA=3-bromine-4-methylbenzoate, phen=1,10-phenanthroline) have been solved by single-crystal X-ray diffraction methods. All obtained products were examined and characterized by elemental analysis, molar conductivity, IR, UV and XRD techniques. The thermogravimetric analysis of 1 to 3 was studied, indicating that the decomposition processes of 2 and 3 are different from 1. The mass loss of the first step for 2 and 3 is attributed to the H2O molecules. The three-dimensional IR accumulation spectra of gaseous of 1 to 3 were also recorded. Complex 1 emits strong and bright green fluorescence under UV light at the room temperature. The bacteriostatic activities of the three complexes against bacteria, such as Escherichia coli and Staphylococcus aureus, and fungus (Candida albicans) were tested.

Lanthanide complexes with 3-bromine-4-methyl benzoic acid and 1,10-phenanthroline

The crystal structures of complexes (Tb (3-Br-4-MBA)3phen)2(1), (Ho(3-Br-4-MBA)3(phen)H2O)2(2) and (Er(3-Br-4-MBA)3(phen)H2O)2(3) (3-Br-4-MBA=3-bro- mine-4-methylbenzoate, phen=1,10-phenanthroline) have been solved by single-crystal X-ray diffraction methods. All obtained products were examined and characterized by ele- mental analysis, molar conductivity, IR, UV and XRD techniques. The thermogravimetric analysis of 1 to 3 was studied, indicating that the decomposition processes of2 and 3 are different from 1. The mass loss of the first step for2 and 3 is attributed to the H2O molecules. The three-dimensional IR accumulation spectra of gaseous of 1 to 3 were also recorded. Complex 1 emits strong and bright green fluores- cence under UV light at the room temperature. The bacte- riostatic activities of the three complexes against bacteria, such as Escherichia coli and Staphylococcus aureus, and fungus (Candida albicans) were tested.

Jie Gao

Papers

Preparation, characterization and properties of four new trivalent lanthanide complexes constructed using 2-bromine-5-methoxybenzoic acid and 1,10-phenanthroline.

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

Novel lanthanide complexes constructed from 3, 4-dimethoxybenzoic acid: crystal structures, spectrum and thermochemical properties

Lanthanide complexes with 3-bromine-4-methyl benzoic acid and 1,10-phenanthroline

Synthesis, crystal structures, thermal properties and bacteriostatic activities