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Two isostructural lanthanide complexes were synthesized by solvent evaporation with 3-dimethylaminobenzoic acid and 5,5′-dimethyl-2,2′-bipyridine as ligands. The general formula of the structure is a [Ln(3-N,N-DMBA)3(5,5′-DM-2,2′-bipy)]2·2(3-N,N-DMHBA), Ln = (Gd(1), Tb(2)), 3-N,N-DMBA = 3-Dimethylamino benzoate, 5,5′-DM-2,2′-bipy = 5,5′-dimethyl-2,2′ bipyridine. Both complexes exhibited dimeric structures based on X-ray diffraction analysis. At the same time, infrared spectroscopy and Raman spectroscopy were used to measure the spectra of the complex. A thermogravimetric infrared spectroscopy experiment was performed to investigate the thermal stability and decomposition mechanism of the complexes. Measurements of the low-temperature heat capacity of the complexes were obtained within the temperature range of 1.9 to 300 K. The thermodynamic function was calculated by heat capacity fitting. In addition, the fluorescence spectra of complex 2 were studied and the fluorescence lifetime values were determined, and the energy transfer mechanism of complex 2 was elucidated. [ABSTRACT FROM AUTHOR]

2-fluorobenzoic acid and 5,5′-dimethy-2,2′-bipyridine were used to construct two novel isostructural lanthanide complexes [Ln(2-FBA)3(5,5′-DM-2,2′-bipy)]2 (Ln = Eu(1), Tb(2); 2-FBA = 2-fluorobenzoate; 5,5′-DM-2,2′-bipy = 5,5′-dimethy-2,2′-bipyridine) by conventional solution method. They were characterized by infrared spectroscopy (IR), elemental analysis and single-crystal X-ray diffraction. The crystal description based on single-crystal X-ray diffraction data revealed that both of the complexes gave the triclinic crystal structure, belonging to the Pī space group. The two complexes were an infinite one-dimensional (1D) chain by hydrogen bonding (C–H...F) interactions to give a 2D supermolecular structure. Additionally, thermal behavior of the complexes was investigated by TG-DSC/FTIR technology in detail. The molar heat capacities of the two complexes in the temperature range of 278.15-423.15 K were determined by a DSC instrument, and their thermodynamic functions (HT-H298.15 K) and (ST-S298.15 K) were calculated. Beyond that, the fluorescence spectra and fluorescence lifetime of the complexes 1 and 2 were also evaluated. [ABSTRACT FROM AUTHOR]

[Display omitted] • Three new rare earth metal compounds are synthesized and single crystals are obtained. • 1D and 2D structures of compounds are formed by different types of hydrogen bonds. • The thermal behavior of the compounds is studied by TG/DSC-FTIR. • Compound 3 can emit orange-red light and has outstanding fluorescence properties. Three new rare earth coordination compounds [REL 3 Ph] 2 (RE = Pr(1), Sm(2)); [ErL 3 Ph] 2 ·4C 2 H 5 OH(3); (L = 2,6-dimethylbenzoate, Ph = o-phenanthroline) were synthesized. The crystal structures of the three compounds were measured by X-ray single-crystal diffraction. From the results, we made out that compounds 1–3 were binuclear structures, and 1D chain-like structures could be formed by hydrogen bonding. The thermal degradation data of the compounds and the three-dimentional infrared cumulative spectra of the gaseous decomposed products were obtained by TG/DSC-FTIR technique, and the thermal degradation patterns were explained. The isobaric molar heat capacity of compounds 1 and 2 in the low-temperature region was obtained by the DSC technique and the thermodynamic parameters were derived. The fluorescence spectrum of compound 2 was determined, showing that it had potential application value in the orange-red luminescence region. [ABSTRACT FROM AUTHOR]

Six noble two-dimensional lanthanide complexes [Ln(2,4-DFBA) 3 (terpy)·H 2 O]·H 2 O (Ln = Tb(1), Dy(2)), [Pr(2,4,6-TMBA) 3 (terpy)·H 2 O] (3) [Nd(2,4,6-TMBA) 3 (terpy)·H 2 O]·C 2 H 5 OH·H 2 O(4) and [Ln(2,4,6-TMBA) 3 (terpy)·H 2 O]·1.5H 2 O (Ln = Dy(5), Ho(6) (2,4-DFBA = 2,4-difluorobenzoate, 2,4,6-TMBA = 2,4,6-trimethylbenzoate, terpy = 2,2 ': 6′, 2 ''- terpyridine) were synthesized by conventional solution method with 2,4-difluorobenzoic acid and 2,4,6-trimethylbenzoic acid as main ligands and 2,2 ': 6′, 2 ''- terpyridine as auxiliary ligands. The complexes were characterized by infrared spectroscopy and Raman spectroscopy, and the thermal decomposition mechanism of the complex was studied by TG-DTG-DSC/FTIR coupling technology. The solid fluorescence test was also carried out for complexes 1 , 2 and 4. It was found that the complexes have good fluorescence properties, and the fluorescence lifetime of complex 1 was 0.541 ms. [ABSTRACT FROM AUTHOR]

The complexes 1 and 2 are isostructural. The centre Ln3+ ions are nine-coordinated with a distorted monocapped square antiprismatic coordination geometry. The binuclear molecules are linked to form 1D, 2D supramolecular structures through the same C–H⋯O hydrogen bonding interactions. The thermal decomposition processes of complexes 1 and 2 are investigated by TG-DSC/FTIR technology and the FTIR spectra of the escaped gas also are measured. The molar heat capacity values of complexes 1 and 2 indicates that that no phase transition occurs in this range in temperature range from 295.15 to 410.15 K, and the heat capacity values of the complexes increases gradually with the increase of temperature. The luminescence studies reveal that complex 1 with Eu3+ ion shows a strong red luminescence behavior, and the Eu3+ ion in complex 1 do not occupies a site with an inversion center. The luminescence lifetime and fluorescent quantum yield of complex 1 are calculated to be 1.442 ms and 18.96%. • The crystal structures of two lanthanide binuclear complexes were obtained. • The 1D, 2D supramolecular structures through the same C–H⋯O hydrogen bonding interactions were assembled. • The thermal decomposition processes and TG‐FTIR spectroscopy was investigated. • The molar heat capacities and thermodynamic functions were calculated. • The luminescence spectrum of two complexes, lifetime and fluorescent quantum yield of the complex 1 were studied. By using conventional solution method, two novel binuclear lanthanide complexes, [Eu(2,6-DMBA) 3 (5,5′-DM-2,2′-bipy)] 2 (1), and [Sm(2,6-DMBA) 3 (5,5′-DM-2,2′-bipy)] 2 (2) (2,6-DMBA = 2,6-dimethylbenzoate, 5,5′-DM-2,2′-bipy = 5,5′-dimethy-2,2′-bipyridine), have been synthesized at room temperature. The two complexes are characterized by element analysis, single-crystal X-ray diffraction analyses and powder X-ray diffraction. The single-crystal analyses results indicate they are isomorphous in the monoclinic space group of P2(1)c. The binuclear complexes 1 and 2 are linked to form 1D, 2D supramolecular structures through the same C–H⋯O hydrogen bonding interactions. The thermal decomposition process of these complexes is investigated by TG-DSC/FTIR technology and the FTIR spectra of the escaped gas also are measured. In addition within a temperature range from 295.15 K to 410.15 K, heat capacities of the title complexes are measured by a DSC instrument, which indicates that no phase transition occurs in this range, and the heat capacity values of the complexes gradually increases with rising temperature. Not only that, the thermodynamic functions values (H T -H 298.15K) and (S T -S 298.15K) of the complexes 1 and 2 are calculated according to the fitted polynomial equations and the thermodynamic equation. The luminescent behaviour of complex 1 is investigated in the solid state. The complex 1 with Eu3+ ion shows strong red luminescence behaviour, and the luminescence lifetime and fluorescent quantum yield are calculated to be 1.442 ms and 18.96%. [ABSTRACT FROM AUTHOR]

Three novel lanthanide complexes [Er (3,4‐DMBA)3(5,5′‐DM‐2,2′‐bipy)(H2O)] (1); [Tb2 (3,4‐DMBA)6(5,5′‐DM‐2,2′‐bipy)2(H2O)] (2); [Eu (3,4‐DMBA)3(3,4‐DMHBA)(5,5′‐DM‐2,2′‐bipy)]2 (3) (3,4‐DMHBA = 3,4‐dimethylbenzoic acid, 5,5′‐DM‐2,2′‐bipy =5,5′‐dimethyl‐2,2′‐bipyridine) were successfully synthesized via conventional solution method at room temperature and structurally characterized by single crystal diffraction. The structures of the complexes 1–3 were confirmed on the basis of elemental analysis, coordination titration analysis, IR and XRD. The molecular structures of complexes 2 and 3 are very particular: complex 2 has two same central metal ions but each metal ion has different coordination environment; in structure of the complex 3, there are eight carboxylic acid ligands coordinated to the central metal ions, which have rarely been reported previously. The thermal decomposition mechanism of complexes 1–3 were investigated by the technology of simultaneous TG/DSC‐FTIR. The heat capacities of the complexes were recorded by means of DSC over the range of from 253.15 K to 345.15 K. The thermodynamic parameters, the smoothed values of heat capacities, enthalpy (HT‐H298.15K) and entropy (ST‐S298.15K) were also calculated. The bacteriostatic activities of the complexes were evaluated against Staphylococcus aureus, Escherichia coli and Candida albicans. What's more, the luminescence properties of complexes 2 and 3 were discussed, and their fluorescence lifetimes as well as the quantum yield of the Eu (III) were measured. To elucidate the energy transfer process of complexes 2 and 3, the energy levels of the relevant electronic states have been estimated. [ABSTRACT FROM AUTHOR]

Five dinuclear trivalent lanthanide complexes, [Ln(3-MOBA) 3 (5,5′-DM-2,2′-bipy)] 2 (Ln = Er(1), Ho(2), Eu(3), Pr(4), Nd(5); 3-MOBA = 3-methoxybenzoate; 5,5′-DM-2,2′-bipy = 5,5′-dimethyl-2,2′-bipyridine) have been successfully synthesized via conventional solution method at room temperature and structurally characterized by single crystal and powder X-ray diffraction. The molecular structures of complexes 1 – 5 are very novel-innovative. Complexes 1 and 2 were isomorphic, and the complex 1 was obtained with the coordination number of eight to form a distorted square-antiprism coordination geometry, while complexes 3 – 5 were nine-coordinated with a distorted monocapped square antiprismatic coordination geometry, but they can be all assembled into the same 1D, 2D supramolecular structure, which has rarely been reported previously. Over the temperature range of 300–1200 K, the thermal decomposition mechanism of complexes 1 – 5 were discussed by the technology of TG/DSC-FTIR. The luminescence spectra of complex 3 displayed the characteristic emission of Eu 3+ ion ( 5 D 0  →  7 F 0-4 ), and it’s CIE coordinate was also calculated as (0.647, 0.341). In addition, the luminescence lifetime and intrinsic luminescence quantum yield were also investigated. Beyond that, the magnetic properties of complexes 1 – 2 were studied in detail. [ABSTRACT FROM AUTHOR]

Two ternary lanthanide complexes [Ln(2-Br-5-MOBA) 3 (5,5′-DM-2,2′-DIPY)] 2 (Ln = Sm(1), Eu(2); 2-Br-5-MOBA = 2-bromo-5-methoxybenzoate; 5,5′-DM-2,2′-DIPY = 5,5′-dimethyl-2,2′-bipyridine) with 2-bromo-5-methoxybenzoic acid and 5,5′-dimethyl-2,2′-bipyridine have been synthesized and characterized. The Single-crystal X-ray diffraction date show that complexes 1 and 2 are isostructural in the triclinic system, space group P 1 ¯ . Infrared spectra (IR) and X-ray powder diffraction (PXRD) further confirm that complexes 1 and 2 are isostructural. The basic structural unit forms a 1D chain through the weak C H⋯Br hydrogen bond interaction along the b-axis, and forms a 2D sheet through the π–π stacking interactions along the a-axis. The 2D sheets are further interconnected by the C H⋯O hydrogen bond interaction to assembled into a 3D supramolecular network along the c-axis. In addition, the simultaneous thermal analysis (TG, DTG and DSC) of the complexes and the FTIR spectra of the escaped gas were measured. The heat capacities of the complexes were determined by DSC in the temperature region of 258.15–393.15 K. Furthermore, the luminescence spectrum of the complexes 1 and 2 and luminescence lifetime of complex 2 were also measured. [ABSTRACT FROM AUTHOR]

Abstract: Two novel binuclear lanthanide complexes [Ln(2, 5‐DClBA)3(5,5’‐DM‐2,2’‐bipy)(H2O)]2(5,5’‐DM‐2,2’‐bipy) (Ln=Eu(1), Tb(2)); 2,5‐DClBA=2,5‐dichlorobenzoate; 5,5’‐DM‐2,2’‐bipy=5,5’‐dimethyl‐2,2’‐bipyridine) have been successfully synthesized via conventional solution method and then characterized by single‐crystal X‐ray diffraction and elemental analysis. These two binuclear complexes differ from other reported binuclear complexes, because the free neutral ligands are not common in crystal structure. The complexes are isomorphic, which have the same coordination number of eight with a distorted square antiprismatic molecular geometry. The binuclear units feature hydrogen bonding (O−H⋅⋅⋅N and C−H⋅⋅⋅Cl) and π‐π stacking interactions assemble the adjacent molecular units into 1D, 2D and 3D supramolecular novel structures. It is worth noting that the novel 1D supramolecular structure is formed by the hydrogen bonding interaction between the nitrogen atoms of free 5,5’‐DM‐2,2’‐bipy ligand and the oxygen atom of the coordination water molecule. The thermal decomposition mechanism of the two complexes were studied by TG/DSC‐FTIR techniques. Additionally, the luminescence spectra and lifetime have been studied in detail. The results indicate that Eu3+ ion and Tb3+ ion could be sensitized by ligands and thus emitted intense characteristic red and green luminescence, respectively. [ABSTRACT FROM AUTHOR]

Two lanthanide complexes [La(3,4-DMBA)3]n (1) and [Tb(3,4-DMBA)3(DIPY)2]2 (2) (where 3,4-DMBA = 3,4-dimethylbenzoate, DIPY = 2,2′-bipyridine) have been synthesized and then characterized. The single crystals of complexes 1 and 2 were obtained. Complex 1 adopts a distorted monocapped square antiprismatic molecular geometry, while complex 2 forms a distorted square antiprism. Complex 1 is stitched together by edge sharing through carboxylate ligands to form 1D chains along the b axis. The structure of complex 2 consists of 1D chains along the c axis by two kinds of π···π stacking interactions. Two complexes were characterized by elemental analysis, powder X-ray diffraction and IR spectra. The complex 2 shows typical green luminescence in the solid state. Thermal decomposition mechanisms of complexes were discussed by TG–DTG techniques. In the temperature range from 257.15 to 413.15 K, the molar heat capacities of the complexes were measured by DSC. The smoothed heat capacities and thermodynamic functions of complexes were calculated on the basis of fitted polynomial and thermodynamic equations. [ABSTRACT FROM AUTHOR]

Three novel ternary lanthanide complexes [Ln(2,5-DClBA)3(terpy)(H2O)] (Ln = Eu (1), Tb (2), Ho (3), 2,5-DClBA = 2,5-dichlorobenzoate, terpy = 2,2:6′,2″-terpyridine) have been successfully synthesized and characterized by single-crystal and powder X-ray diffraction. Complexes 1–3 are isostructural, and each metal center is nine-coordinated with distorted monocapped square antiprismatic coordination geometry. The mononuclear units are assembled into 1D, 2D, 3D supramolecular structures by the π–π stacking and halogen–halogen interactions. Thermal decomposition mechanisms of the title complexes were investigated by thermogravimetric analysis and further authenticated by TG/DSC-FTIR techniques. The solid-state fluorescent properties of complexes 1–2 were studied at room temperature, and characteristic emission was observed for all complexes. Complex 1 exhibits the strong red emission, while the complex 2 is green under UV light. Moreover, the antibacterial activities of the complexes against Candida albicans, Escherichia coli and Staphylococcus aureus were also evaluated. [ABSTRACT FROM AUTHOR]

Three novel Ho(III) complexes, [(Ho(2-Br-5-MOBA) 3 (terpy)(H 2 O)] ( 1 ), [Ho(2-Br-5-MOBA) 3 (2,2′-bipy)] 2 ( 2 ) and [Ho(2-Br-5-MOBA) 3 (5,5′-DM-2,2′-bipy)] 2 ( 3 ) (2-Br-5-MOBA = 2-bromine-5-methoxybenzoate, terpy = 2,2:6′,2″-terpyridine, 2,2′-bipy = 2,2′-bipyridine, 5,5′-DM-2,2′-bipy = 5,5′-dimethy-2,2′-bipyridine), have been synthesized and characterized by single-crystal X-ray diffraction. Although 1 – 3 have the same triclinic crystal system and P 1 ¯ space group, they show three different types of molecule structures. For 1 , it is mononuclear and fake binuclear units constituted by the mononuclear molecules are stitched together via π–π stacking and C–H⋯O hydrogen bonding interactions to form the 1D, 2D supramolecular structure. Complexes 2 and 3 are binuclear structures with the different coordination numbers, which are assembled into 1D, 2D, 3D supramolecular structures by different intermolecular interactions. This is because of the different auxiliary ligands. The thermal decomposition mechanism of complexes 1 – 3 were studied by TG analysis and further authenticated by TG/DSC-FTIR techniques, indicating that the difference of the auxiliary ligand affects the thermal stabilities of complexes. The average molar heat capacity values of the complexes gradually increased with an increase of temperature, indicating the complexes have good thermal stability within this range of temperature. In addition, the IR, PXRD, and the antibacterial activities of complexes 1 – 3 were measured. [ABSTRACT FROM AUTHOR]

The lanthanide coordination complexes Er(2,3-DMOBA)3(terpy)(H2O) (1) and [Nd(2,3-DMOBA)3(terpy)(H2O)]2 (2) (2,3-DMOBA = 2,3-dimethoxybenzoate; terpy = 2,2':6',2'-terpyridine) were synthesized and characterized by IR spectroscopy, powder X-ray diffraction (XRD), single-crystal X-ray diffraction, and thermogravimetric analysis. Complex 1 crystallizes in the triclinic system, space group P1-, and the mononuclear subunits form a 1D chain structure along the a axis by hydrogen bonds. Complex 2 crystallizes in the monoclinic system, space group P21/c, and the dinuclear subunits are further linked via the offset face-to-face π⋯π weak stacking interactions to form a supramolecular 2D layered structure. Thermal analysis showed that the complexes have three decomposition steps. The first step is the loss of coordination water molecules. The neutral terpy ligands and partial 2,3-DMOBA ligands are lost in the second step. The remaining 2,3-DMOBA ligands are lost in the third step. The 3D stacked plots for the FT-IR spectra of the evolved gases are recorded and the gaseous products are identified by the typical IR spectra obtained at different temperatures from the 3D stacked plots. Meanwhile, the results of the antibacterial action tests show that 1 and 2 have better antibacterial activities to Candida albicans than to Escherichia coli or Staphylococcus aureus. In addition, complex 2 has better antibacterial action to Candida albicans than complex 1. [ABSTRACT FROM AUTHOR]

Two novel mononuclear lanthanide complexes, [Ln(2,4-DClBA)(terpy)(HO)]·HO (Ln = Dy(1), Er(2)); 2,4-DClBA: 2,4-dichlorobenzoate; terpy: 2,2′:6′,2″-terpyridine; have been synthesized and characterized by single-crystal and powder X-ray diffraction. The results reveal that complexes 1-2 are isomorphous, and each Ln ion is nine coordinated adopting a distorted monocapped 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, which the 3D is rarely observed. Thermal decomposition mechanism is determined by TG/DSC-FTIR, and the 3D stacked plots for the FTIR spectra of the evolved gases were recorded. Heat capacities of complexes 1-2 were measured, and the derived thermodynamic functions ( H − H ), ( S − S ) and ( G − G ) of the complexes relative to the standard reference temperature 298.15 K were obtained. The activation energy E values of the first decomposition stage for title complexes were calculated by integral isoconversional nonlinear (NL-INT) and Starink methods. Complex 1 shows the characteristic emission of Dy with strong yellow emission. [ABSTRACT FROM AUTHOR]

The crystal structures of complexes [Tb(3-Br-4-MBA)phen]( 1), [Ho(3-Br-4-MBA)(phen)HO]( 2) and [Er(3-Br-4-MBA)(phen)HO]( 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 HO 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. [ABSTRACT FROM AUTHOR]

[Display omitted] Five new lanthanide complexes were synthesized by two different experimental methods: two mononuclear complexes and three binuclear complexes. Their chemical formula is: [Gd(2-Cl-4-FBA) 3 (terpy)H 2 O]1.5H 2 O(1); [Dy(2-Cl-4-FBA) 3 (terpy)H 2 O]·0.5H 2 O(2)) (2-Cl-4-FBA = 2-chloro- 4-fluorobenzoate,terpy = 2,2′:6′,2″-terpyridine); [Ln(3,4-DFBA) 3 (5,5′-DM-2,2′-bipy)(H 2 O)] 2 (Ln = Pr(3),Er(4);[Ln(3,4-DFBA) 3 (5,5′-DM-2,2′-bipy)] 2 (Ln = Ho(5)) (3,4-DFBA = 3, 4-difluorobenzoate,5,5′-DM-2,2′-bipy = 5,5′-dimethyl-2,2′-bipyridine). A series of characterization and properties of the complexes were studied, such as elemental analysis, single crystal X-ray diffraction, thermogravimetric analysis, fluorescence properties and so on. The coordination number of complexes 1–2 is 9, showing a muffin geometry. The results show that complex 1–5 crystallized in the triclinic system and space group P ī. Complexes 1 and 2 are isostructural except for the number of free water molecules. Complexes 3–5 are binuclear molecules with different structures. Although the structures of the five complexes are different, they all form one and two-dimensional supramolecular structures along a chain and a plane. The thermal decomposition mechanism of complexes 1–5 was studied by synchronous thermal analyzer infrared spectroscopy (TG/DSC-FTIR). The results show that the coordination water, neutral ligand and acidic ligand are lost in turn when the complex undergoes thermal decomposition. And the three-dimensional infrared images of gas escaping during the thermogravimetric process were analyzed. In addition, the solid state fluorescence spectra of complex 2 was measured and the results showed that the characteristic fluorescence of Dy(III) ion was emitted. [ABSTRACT FROM AUTHOR]

• Three new Ln(Ⅲ) complexes were synthesized and structures were characterized. • Mononuclear and binuclear were assembled into supramolecular structures. • X-ray crystal structure and the infrared spectrum. • Dy3+ and Tb3+ complexes show luminescence of the trivalent lanthanides. • The thermal decomposition mechanism was investigated by TG-DSC/FTIR. Three new lanthanide complexes were synthesized by conventional solution synthesis at room temperature with the formula of [Ln(2-FBA) 2 (terpy)(NO 3)(H 2 O)]·(terpy)·H 2 O(Ln=Dy(1)), [Ln(2-FBA) 3 terpy] 2 ·2(2-FHBA)·2H 2 O(Ln=Pr(2),Tb(3)), (2-FBA=2-fuorobenzoate, terpy=2,2′:6′,2″-terpyridine). The complexes were characterized by elemental analysis, X-ray single crystal diffraction and infrared spectroscopy. The coordination number of complexes 1–3 is 9, showing a muffin geometry. Complex 1 is mononuclear, crystallized in the monoclinic system and space group P2 1 /c. Complexes 2 and 3 are binuclear molecules of isomorphous, and their adjacent structural units form 1D chain and 2D sheets structure through C-H···F hydrogen bonding and π-π stacking interactions. In addition, the solid state fluorescence spectra of complexes 1 and 3 were measured. The test shows that complex 3 emits strong green light. The thermal decomposition mechanism of the complexes was studied by synchronous thermal analyzer infrared spectroscopy TG-DSC/FTIR and the 3D stacked plots of the escape gases were analyzed. [ABSTRACT FROM AUTHOR]

A new family of binuclear lanthanidecompounds of general formula [Ln(2,4-DClBA)3phen]2(Ln(III) = Nd (1), Sm (2), Dy (3), Yb (4); 2,4-DClBA = 2,4-dichlorobenzoate; phen =1,10-phenanthroline) have been synthesized and characterized by elementalanalysis, molar conductance, infrared spectroscopy, ultraviolet spectra,thermogravimetric analysis, and single-crystal X-ray diffraction.On the basis of X-ray crystallography, compounds 2–4belong to the triclinic crystal system, PI̅ space group. In compound 2, the Sm3+ion adopted a distorted monocapped square-antiprism coordinationgeometry. Compounds 3and 4are isomorphouswhose central ions (Dy3+and Yb3+) formed adistorted square-antiprism geometry. The heat capacities of compounds 1–4are measured using DSC technologyand fitted to a polynomial equation by the least-squares method. Thesmoothed molar heat capacities and thermodynamic function data ofcompounds 1–4relative to the referencetemperature 298.15 K are then calculated. Meanwhile, these compoundsexhibit in good antifungal activity against C. albicans, good antibacterial activity against S. aureus, and better antibacterial activity against E. coli. The fluorescence spectra of the samarium and dysprosium compoundsbehave as characteristic transitions of Sm(III) and Dy(III) ions. [ABSTRACT FROM AUTHOR]

Abstract: The synthesis and structure determination of five novel lanthanide complexes {[Ln(3,5-DmeoxBA)3(phen)]2 (Ln=Pr(1) Nd (2), Sm (3), Eu (4), and Ho (5); 3,5-DmeoxBA = 3,5-Dimethoxybenzoate; phen=1,10-phenanthroline)} are reported. In the isomorphous complexes 1 to 5, two Ln3+ ions are connected together by four bridging 3,5-DmeoxBA ligands. Each Ln3+ ion is octa-coordinated, yielding a distorted square-antiprism comformation. The thermal properties of the title complexes were investigated by simultaneous TG/DSC-FTIR techniques. The activation energy E values of the first decomposition stage for complexes 1 to 5 were calculated by integral iso-conversional non-linear (NL-INT) and Starink methods. Heat capacities of the five complexes were measured by differential scanning calorimetry (DSC). And the values of the experimental heat capacities were fitted to a polynomial equation with the least-squares method. Furthermore, based on the fitted polynomial and thermodynamic equations, the smoothed heat capacities and thermodynamic functions (HT–H298.15K), (ST–S298.15K), and (GT–G298.15K) were calculated. The fluorescent property of complex 4 was also studied. [Copyright &y& Elsevier]

Two novel complexes ([Ln(3,5-Dipr-2-OHBA)3(phen)]2(Ln = Dy(1), Yb(2); 3,5-Dipr-2-OHBA = 3,5-diisopropylsalicylicacid; phen = 1,10-phenanthroline)) were synthesized and characterizedby elemental analysis, conductivity measurements, IR spectra, singlecrystal X-ray diffraction, and thermogravimetric differential scanningcalorimetry/Fourier transform infrared (TG/DSC-FTIR) technology. Thefluorescent property of complex 1 was also studied. The two binuclearcomplexes are isostructural. Each Ln3誉 is octa-coordinated,yielding a trigondodecahedron conformation. The thermal propertiesof the title complexes were investigated by simultaneous TG/DSC-FTIRtechniques. The kinetic parameters of the first decomposition stagefor the complexes were calculated by the integral isoconversionalnonlinear method (NL-INT method), Starink method, Kissinger’smethod, and Ozawa–Doyle’s method. The thermodynamicparameters (ΔH≠, ΔG≠, and ΔS≠) at the peak temperatures of the DTG curves were alsocalculated. Heat capacities of the two complexes were measured byDSC. The values of the experimental heat capacities were fitted toa polynomial equation with the least-squares method. Besides, thesmoothed heat capacities and thermodynamic functions (HT– H298.15K),(ST– S298.15K), and (GT– G298.15K) were calculated. [ABSTRACT FROM AUTHOR]

Abstract: The complex of [Eu(2,4-DClBA)3(bipy)]2 (2,4-DClBA=2,4-dichlorobenzoate; bipy=2,2′-bipyridine) was obtained and characterized by elemental analysis, IR spectra, UV spectra, luminescence spectra, 1H NMR spectra, single crystal X-ray diffraction and TG–DTG techniques. Two Eu3+ ions are connected by four carboxylate groups through bridging bidentate and bidentate chelating-bridging mode. The coordination number of europium ion is nine. The thermal decomposition behavior of the title complex under a static air atmosphere can be discussed by TG–DTG, SEM and IR techniques. The non-isothermal kinetics was investigated by using double equal-double steps method and Starink method. The mechanism function of the first decomposition step was determined. Meanwhile, the thermodynamic parameters (ΔH ≠, ΔG ≠ and ΔS ≠) and kinetic parameters (activation energy E and the pre-exponential factor A) were also calculated. [Copyright &y& Elsevier]

Four new 2D complexes namely [Ln(2-Cl-4-FBA) 3 (terpy)H 2 O] (Ln=Er(1),Ho(2)); [Eu(2-Cl-4-FBA) 3 (terpy)H 2 O]·1.5H 2 O(3); [Tb(2-Cl-4-FBA) 3 (terpy)H 2 O]·2H 2 O (4); (2-Cl-4-FBA=2-chloro-4-fluorobenzoate,terpy=2,2':6′,2 ″-terpyridine) were synthesized at normal temperature. The structures of complexes were determined by single-crystal X-ray diffraction. The results show that the two complexes 1-2 are isomorphous and complexes 3-4 are isostructural. Four complexes are both assembled into the 1D and 2D supramolecular structures through the C-H⋯Cl hydrogen bond interactions. The thermal decomposition mechanism of complexes 1-4 was investigated by the technology TG/DSC-FTIR. FTIR spectra were obtained by analyzing the evolved gases in the thermal decomposition process of complexes 1-4. In addition, the differential scanning calorimetry was used to measure the average molar melting values of the complexes 1-2 in the temperature range of 259.15-343.15K by a specific heat comparison method, and the thermodynamic function values were obtained by calculation. The fluorescence tests of complexes 3 and 4 show that both of them have certain luminescent properties. Four new 2D complexes were synthesized at normal temperature. Four complexes are both assembled into the 1D, 2D supramolecular structures through the C-H⋯Cl hydrogen bond interactions. The thermal decomposition mechanism of complexes 1-4 were investigated by the technology TG/DSC-FTIR. The thermogravimetric analysis shows that complexes giving the final products rare earth oxide. In addition, differential scanning calorimetry was used to measure the average molar melting values of the two complexes in the temperature range of 259.15-343.15K by specific heat comparison method, and the thermodynamic function values were obtained by calculation. The fluorescence tests of complexes 3 and 4 show that both of them have certain luminescent properties. [Display omitted] • Four new isostructural lanthanide complexes had been synthesized and characterized. • Mononuclear structures were assembled into 1D, 2D supramolecular structures. • Thermal behavior of the complexes was investigated by the TG/DSC-FTIR methods. • The heat capacities of complexes 1-2 were measured and the parameters were calculated. • Eu3+ and Tb3+ complexes exhibited red and green luminescence. [ABSTRACT FROM AUTHOR]

Abstract: 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, D c =1.568Mg/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. [Copyright &y& Elsevier]

Four lanthanide complexes derived from the 2,2′:6′,2′′-terpyridine and 2,6-dimethylbenzoic acid have been successfully synthesized, and the luminescent properties of Sm(III), Eu(III) and Tb(III) complexes were studied and show good potential as fluorescent materials. [Display omitted] • Four novel lanthanide binuclear complexes have been successfully synthesized. • The 1D, 2D supramolecular structures were assembled. • The thermal decomposition mechanism was investigated by TG-DSC/FTIR. • The luminescent properties for complexes were investigated. Four 2D lanthanide complexes [Ln(2,6-DMBA) 2 (terpy)(NO 3)] 2 ·4(terpy) (Ln = Sm(1), Eu(2), Gd(3), Tb(4)); 2,6-DMBA = 2,6-dimethylbenzoate; terpy = 2,2′:6′,2′′-terpyridine) were obtained via conventional solution method at room temperature. The crystal structures are characterized by IR, X-ray single crystal diffraction and elemental analysis. The results show that the four complexes are isomorphic, and the coordination number of each metal center is nine, showing a distorted monocapped square anti-prismatic geometry. The complexes 1 - 4 form a 2D supramolecular framework structure by C H⋯O hydrogen bond interactions. The thermal decomposition mechanism of complexes 1 - 4 were investigated by the technology TG/DSC-FTIR. The luminescence studies show that the crystal complexes 1 , 2 and 4 have good luminescent properties and show good potential as fluorescent materials. The luminescence lifetimes of the Eu(III) and Tb(III) complexes are 1.03 ms and 1.24 ms, respectively. [ABSTRACT FROM AUTHOR]

Two isostructural complexes are assembled into the 1D, 2D supramolecular structures by C-H⋯F hydrogen bonding interactions. Thermal stability as well as pathways of thermal decomposition of both complexes are investigated by means of the TG/DSC-FTIR methods. The differential scanning calorimetry method is applied to measure heat capacities in 262.15–349.15 K temperature range and the C p,m values of two complexes are found to increased steadily with temperature. Additionally, the luminescence spectrum and lifetime of complex 1 have been investigated. • Two isostructural 2D lanthanide complexes had been synthesized and structurally characterized. • Thermal behaviour of the complexes was investigated by the TG/DSC-FTIR methods. • The heat capacities of the complexes were measured and the thermodynamic parameters were calculated. • Tb3+ complex exhibited bright green luminescence with a fluorescence lifetime of 1.054 ms. The reactions of 2,4-difluorobenzoic acid, 5,5′-dimethyl-2,2′-bipyridine with Ln(NO 3) 3 ·6H 2 O resulted in the formation of two isostructural binuclear complexes [Ln(2,4-DFBA) 3 (5,5′-DM-2,2′-bipy)] 2 (H 2 O) 2 (2,4-DFBA = 2,4-difluorobenzoate, 5,5′-DM-2,2′-bipy = 5,5′-dimethyl-2,2′-bipyridine, Ln = Tb (1), Dy (2)). Their structures were first detected by single crystal X-ray diffraction and further characterized by elemental analysis and TG/DSC-FTIR techniques. The X-Ray crystal structures confirmed that each metal ion resided in distorted triangular prism geometry and both of them had triclinic characteristics with P ī space group. Besides, the complexes also existed as one dimensional chain which was further assembled into two-dimensional supramolecular framework via extensive hydrogen bonds (C-H...F). Heat capacities of the complexes were measured by a DSC instrument over the temperature range from T = 262.15–349.15 K. Additionally, the luminescence spectra and lifetime of complex 1 were evaluated. [ABSTRACT FROM AUTHOR]

• Three novel lanthanide mononuclear complexes were synthesized. • The 1D, 2D supramolecular structures were assembled. • The thermal decomposition mechanism was investigated by TG-DSC/FTIR. • The luminescence property of the dysprosium complex was studied. Three mononuclear complexes [Ln(2,6-DMBA) 3 (terpy)] (Ln = Dy(1), Ho(2), Er(3); 2,6-DMBA = 2,6-dimethylbenzoate; terpy = 2,2′:6′,2″- terpyridine) were synthesized via conventional solution method and characterized by elemental analysis, IR spectra, thermal analysis and single X-ray diffraction techniques. The single-crystal X-ray structures of complex 1 – 3 are described here, and the complexes are isomorphous and crystallize in the orthorhombic crystal system Pbcn space group. Each Ln(III) ion is nine-coordinated by six O atoms from three 2,6-DMBA ligands and three N atoms from a terpy molecule, which is defined as a distorted monocapped square anti-prismatic geometry. Each adjacent Ln(III) structural unit forms a 2D supramolecular structure through C H⋯O intermolecular hydrogen bonding interaction. The thermal decomposition mechanism of complexes 1 – 3 were analyzed by TG/DSC-FTIR. The luminescence spectra of Dy(III) complex were studied and the characteristic emission peaks of Dy(III) ion were observed. [ABSTRACT FROM AUTHOR]

• Two novel lanthanide binuclear complexes were synthesized. • The 1D, 2D supramolecular structures were assembled. • The thermal decomposition mechanism was investigated by TG-DSC/FTIR. • The heat capacities of the complexes and thermodynamic functions were obtained. Two 2D lanthanide coordination polymers Ln 2 (2,6-DMBA) 5 (terpy) 2 (NO 3)(H 2 O) 2 (Ln = La(1), Pr(2); 2,6-DMBA = 2,6-dimethylbenzoic; terpy = 2,2′:6′,2′′-terpyridine) were successfully prepared through conventional solution method at room temperature. Their structures were identified by IR, XRD, single crystal X-ray diffraction and elementary analysis. These means show that complexes 1 – 2 are isomorphous. The two identical central metal ions of the binuclear complex have different coordination environments and coordination numbers. Thermogravimetric analyses (TGA) were researched by TG/DSC-FTIR, and showed multi-step decompositions. The heat capacities of complexes 1 and 2 were determined by DSC from 260.15 K to 374.15 K. Furthermore, based on the fitted polynomial and thermodynamic equation, the thermodynamic parameters values of the complexes 1 and 2 were obtained. [ABSTRACT FROM AUTHOR]

Four novel lanthanide coordination complexes, [La(p -ClBA) 3 (5,5′-DM-2,2′-bipy)H 2 O] n (1), [Ln(p -ClBA) 3 (5,5′-DM-2,2′-bipy)H 2 O] 2 (Ln = Sm 2 , Eu 3 , Gd 4) were obtained from the reaction between p -chlorobenzoic acid (p -ClHBA), 5,5′-dimethyl-2,2′-bipyridine (5,5′-DM-2,2′-bipy) and lanthanide nitrate under solvothermal conditions. Single crystal X-ray diffraction analysis showed that complex 1 is a 1D chain structure, crystallized in the monoclinic system, space group P 2(1)/n, and formed a 2D sheet through the C–H⋯O hydrogen bond interactions. While complexes 2 – 4 were binuclear unit and crystallizes isomorphically in the triclinic system, space group P ī. The binuclear unit were assembled into 1D supramolecular structures through the O–H⋯O hydrogen bond interactions along the a-axis and formed a 2D supramolecular structures through the π-π stacking interactions along the b-axis. The thermal analysis of four complexes were studied by TG-DSC/FTIR. The solid state photoluminescent properties of complex 3 were investigated at room temperature. Moreover, the antibacterial activities of complexes 1 – 4 on Candida albicans were studied. • The novel structures of four lanthanide binuclear complexes were obtained. • The 1D, 2D supramolecular structures were assembled. • The thermal decomposition mechanism was investigated. • The luminescence spectrum of the complex 3 were studied. • The antimicrobial activity of complexes 1 – 4 against Candida albicans were studied. [ABSTRACT FROM AUTHOR]

A series of novel trivalent lanthanide complexes, [Ln(2,3‐DMOBA)3(5,5′‐DM‐2,2′‐bipy)]2·C2H5OH (Ln = Eu(1), Sm(2), Gd(3), Ho(4) Er(5), Pr(6), Nd(7)) (2,3‐DMOBA = 2,3‐dimethoxybenzoate, 5,5′‐DM‐2,2′‐bipy = 5,5′‐dimethy‐2,2′‐bipyridine), have been successfully synthesized and structurally validated by single crystal diffraction. All complexes discussed herein feature a binuclear structure, and contain only one free ethanol molecule, which is interesting in the lanthanide complexes. The coordination number of center Ln3+ ions is nine, showing a distorted monocapped square anti‐prismatic coordination geometry. Through a pair of alternating identical C‐H···O hydrogen bonding interactions between two 2,3‐DMOBA ligands on the same lanthanum binuclear unit with 5,5′‐DM‐2,2′‐bipy ligands on two neighboring units, the binuclear complexes can form one‐ The thermal analysis of these complexes are investigated by TG‐DSC/FTIR, the result show that the decomposition process of complexes are mainly divided into four stages with the formation of the respective oxides. The visible light emission experiment of complex 1 is carried out, and the characteristic luminescence behavior of intense red light is exhibited. What'more, fluorescence lifetimes as well as the fluorescent quantum yield of complex 1 is calculated. And the magnetic properties of complexes 3–5 are also studied. [ABSTRACT FROM AUTHOR]

Graphical abstract The four complexes show that the two types of crystal structures may be due to the effect of the lanthanide contraction. The mononuclear molecules of complexes 1 and 2 were linked to 1D, 2D supramolecular structure via C H⋯O hydrogen bonding and offset face-to-face π⋯π stacking interactions. The photoluminescence property of complex 4 has been discussed, the result shows that there is a broad excitation band in the UV region of the excitation spectrum, which may be due to the electron transition of π → π∗ between the organic ligands. In addition, the four determined excitation peaks are at 595, 618, 654 and 695 nm corresponding to the transitions of 5D 0 → 7F 1 , 5D 0 → 7F 2 , 5D 0 → 7F 3 and 5D 0 → 7F 4 respectively. The 5D 0 → 7F 2 transition at 618 nm amongst these is the strongest and pure red emission spectrum. From the Fig. a and b, we can also see that the emission spectrum of the complex 4 are similar to that of Eu(NO 3) 3 ·6H 2 O in terms of shape and band positions, but the peak intensity in the case of complex 4 is much stronger than that of Eu(NO 3) 3 ·6H 2 O, suggesting that the ligands of aromatic carboxylic and terpy provide additional sensitized luminescence support for asymmetric Eu(III) ion. Highlights • Four new lanthanide complexes have been successfully synthesized. • The title complexes have two types of structure arrangements. • Complexes can be all assembled into the 1D and 2D supramolecular structure. • The thermodynamic properties for title complexes were studied. • The luminescent properties for complex 4 were in-depth investigated. Abstract A series of ternary mononuclear complexes Ln(3,4-DMBA) 3 (terpy)(H 2 O), (Ln = Er (1), Ho (2)) and ternary dinuclear complexes [Ln(3,4-DMBA) 3 (terpy)(H 2 O)] 2 (Ln = Pr (3), Eu (4)) (3,4-DMBA = 3,4-dimethylbenzoate; terpy = 2,2:6′,2″-terpyridine) were successfully synthesized and characterized by element analysis, coordination titration analysis, and powder X-ray. Among them, we obtained three kinds of single crystals. Complexes 1 and 2 were obtained with a coordination number of eight to form a distorted triangular dodecahedron, while complex 3 was nine-coordinated with a distorted triangular prismatic coordination sphere. The thermal decomposition mechanism of complexes 1 – 4 were investigated by TG/DSC-FTIR. What′s more, the luminescence property of complex 4 was discussed, and the fluorescence lifetime of complex 4 was measured. Based on the emission data, complex 4 was a promising candidate for a red component in an ultraviolet. [ABSTRACT FROM AUTHOR]