Luminescence Properties Of Complexes Research Articles

Lanthanide coordination polymers based on an aromatic dicarboxylic acid and 1,10-phenanthroline ligands: synthesis, structure and luminescence properties

A novel series of lanthanide coordination polymers (Ln-CPs) have been obtained based on mixed ligands, 2-[(4-carboxyphenyl)methoxy]benzoic acid (H2cob) and 1,10-phenanthroline (phen), namely {Ln[(Hcob)(cob)(phen)]n, Ln = La (1), Pr (2), Sm (3), Eu (4)}. Complexes 1–4 were characterized by single crystal X-ray diffraction, elemental analysis, powder X-ray diffraction, infrared spectroscopy and thermogravimetric analysis. Single crystal X-ray diffraction revealed that complexes 1–4 show two-dimensional layer structures. The luminescence properties of complexes 3 and 4 were thoroughly investigated.

Cd(II) and Zn(II) complexes with 2-mercaptopyridine: Synthesis, crystal structure, Hirshfeld surface analysis, luminescent properties, aggregation behaviours, current-voltage characteristic and antibacterial assay

Two transition metal complexes viz. [Cd(2-mcpH)4](NO3)2 (1) and [Zn(2-mcpH)4](NO3)2 (2) were synthesized by the reaction of cadmium(II) nitrate tetrahydrate or zinc(II) nitrate hexahydrate with 2-mercaptopyridine (2-mcpH) in 1:4 M ratio. These complexes have been fully characterized by UV–Vis, IR, NMR–spectroscopy and Single crystal X-ray analysis. Luminescent properties of complex 2 were also investigated. The emission seen in complex 2 is accredited due to the π⋯π* intra-ligand transitions. The structural architecture of both complexes manifested as monomeric tetra-coordinated M−centers, each adeptly coordinated by four 2-mcpH ligands. These arrangements effectively neutralized the complex charge, employing two nitrate groups. Concurrently, Hirshfeld surfaces analysis showed maximum interactions of 25.6%, 26.6% for H⋯H, and 25.0%, 25.1% for O⋯H contacts in complexes 1 and 2, respectively. In current–voltage (I-V) characteristic studies, it has been observed that both complexes showed Ohmic behavior. FESEM studies give convincing visual facts of the aggregation behaviour of two complexes. To appraise their potential, the ligand and complexes were subjected to antibacterial s. Complex 1 showed the most potent antibacterial effect, particularly against Gram-negative bacteria, while complex 2 exhibited a moderate effect against both Gram-negative and Gram-positive bacteria.

A Series of Novel 3D Coordination Polymers Based on the Quinoline-2,4-dicarboxylate Building Block and Lanthanide(III) Ions-Temperature Dependence Investigations.

A series of novel 3D coordination polymers [Ln2(Qdca)3(H2O)x]·yH2O (x = 3 or 4, y = 0-4) assembled from selected lanthanide ions (Ln(III) = Nd, Eu, Tb, and Er) and a non-explored quinoline-2,4-dicarboxylate building block (Qdca2- = C11H5NO42-) were prepared under hydrothermal conditions at temperatures of 100, 120, and 150 °C. Generally, an increase in synthesis temperature resulted in structural transformations and the formation of more hydrated compounds. The metal complexes were characterized by elemental analysis, single-crystal and powder X-ray diffraction methods, thermal analysis (TG-DSC), ATR/FTIR, UV/Vis, and luminescence spectroscopy. The structural variety of three-dimensional coordination polymers can be ascribed to the temperature effect, which enforces the diversity of quinoline-2,4-dicarboxylate ligand denticity and conformation. The Qdca2- ligand only behaves as a bridging or bridging-chelating building block binding two to five metal centers with seven different coordination modes arising mainly from different carboxylate group coordination types. The presence of water molecules in the structures of complexes is crucial for their stability. The removal of both coordinated and non-coordinated water molecules leads to the disintegration and combustion of metal-organic frameworks to the appropriate lanthanide oxides. The luminescence features of complexes, quantum yield, and luminescent lifetimes were measured and analyzed. Only the Eu complexes show emission in the VIS region, whereas Nd and Er complexes emit in the NIR range. The luminescence properties of complexes were correlated with the crystal structures of the investigated complexes.

Spectroscopic investigation, thermal behavior, catalytic reduction, biological and computational studies of novel four transition metal complexes based on 5-methylthiophene Schiff base type

Four new complexes prepared from 5-Methyl-2-carboxaldehyde-thiophene and 2,6-pyridinediamine with cobalt, nickel, copper and cadmium ions have been synthesized because of the significance of these complexes in pharmacological research and catalytic reduction. The prepared compounds were characterized using elemental analysis, mass, UV–visible, NMR and FTIR spectroscopy, as well as molar conductance, magnetic susceptibility measurements, fluorescence properties and TGA analysis. The stoichiometry mode was confirmed as 1:1 (metal: ligand) for Co, Ni and Cu complexes and 1:2 (metal: ligand) for Cd complex according to the results of the elemental and spectral studies. Furthermore, the thermal stability and luminescence properties of complexes have been studied. Thermal studies confirmed the presence of water molecules. The thermodynamic properties of the complexes were measured via the Coats-Redfern procedure. The geometric structures of the complexes were found to be octahedral around the metal ions. The optical energy gaps (Eopt) vary between 2.92 and 3.71 eV indicating that these compounds can be used as selective absorbing solar energy in photovoltaic applications. In the presence of NaBH4, the greatest reduction efficiency for the conversion of 2-NP to 2-AP was discovered to be 73–91% within 15–25 min. In vitro, high antifungal and antibacterial activity was shown by complexes than the ligand alone. The Cd(II) complex was shown to have greater activity than all of the examined microorganisms when compared to the reference drug in addition it had 4.94 μg/ml minimal inhibitory concentration against “S. aureus”, “B. subtilis”, and “E. coli”. The bond angles, bond lengths, and quantum chemical factors of the ligand and complexes were shown in the molecular modeling using the DFT approach. The studied compounds' binding modes were confirmed using the Gaussian 09 program.

Photophysical, optical and lasing analysis of fluorinated β-keto carboxylate europium(III) complexes

Six luminescent, bright red Eu(III) complexes with a β-keto-carboxylic acid as prime ligand and N-donor aromatic systems as auxillary ligand were synthesised via ecologically efficient grinding method. The distinctive red peak (5D0 → 7F2) of Eu(III) ion is exhibited in emission spectra of all complexes. The luminescent properties of complexes were analysed through decay time, color coordinates, luminescence efficiency and Judd Ofelt parameters. The value of Ω2 is found to be higher than Ω4 which indicated hypersensitive nature of 5D0 → 7F2 transition. The results established the complexes as a strong contender for red light emitting display devices. The fluorescence branching ratios, stimulated emission cross section, gain band width and optical gain showed the good lasing strength of 5D0 → 7F2 transition of complexes. The complexes exhibited decent thermal stability and have optical energy band gap value in semiconductor range, thus can have relevance in optoelectronic devices. Energy transfer mechanism was investigated for complexes which affirmed the efficacious transfer of energy from ligands to Eu(III) ion. The synthesised complexes were also assayed for antimicrobial and antioxidant properties. All complexes are reported to show better antioxidant behaviour than the prime ligand and also exhibited upstanding antibacterial activities.

Studies on two phenoxo-bridged homopolynuclear Cu(II) bis(salamo) type complexes based on theoretical calculations and fluorescence properties

The dinuclear Cu(II) complex [Cu2(HL)Br2(MeOH)]·MeOH (1) and the tetranuclear Cu(II) complex [Cu4(L)2](ClO4)2·2EtOH (2), based on a new bis(salamo) type ligand H3L, have been successfully self-assembled and structurally characterized by X-ray single crystal diffraction experiments. In complex 1, the partially deprotonated ligand unit (HL)2– is coordinated with the Cu(II) ions. It is noteworthy that two bromine ions and one methanol molecule with balanced charges are involved in the coordination. Both central coordination Cu(II) ions are five-coordinated. Finally, complex 1 can form a two-dimensional planar network structure and a one-dimensional chain-like structure through intermolecular hydrogen bonds and CH π interactions, respectively. Meanwhile, complex 2 has a centrosymmetric structure with two phenolic oxygen atoms bridging two molecules of metallized ligand [Cu2(L)] units, where Cu1 is five-coordinated and Cu2 is four-coordinated. Thus, complex 2 forms a three-dimensional superamolecular network structure and a one-dimensional chain-like structure through intermolecular hydrogen bonds and π–π stacking interactions, respectively. The energy gaps between the HOMO and LUMO orbitals of complexes 1 and 2 were investigated by DFT calculations, indicating that the complexes are stable. The interaction sites of the ligand with the Cu2+ ions were examined by ESP investigation, and the results are consistent with the crystal structure. The weak intermolecular interaction forces of complexes 1 and 2 were explored by Hirshfeld surfaces and IRI analyses. The luminescent properties of complexes 1 and 2 were illustrated by fluorescence spectroscopy research.

Two zinc and cadmium coordination polymers constructed with bis(4-(1H-imidazol-1-yl)phenyl)methanone and naphthalene-1,4-dicarboxylate ligands: synthesis and structural characterization

Abstract Two coordination polymers, [Zn2(bipmo)2(1,4-nda)2] n (1), {[Cd(bipmo)(1,4-nda)]·(H2O)} n (2), (bipmo = bis(4-(1H-imidazol-1-yl)phenyl)methanone, H2(1,4-nda) = naphthalene-1,4-dicarboxylic acid), were synthesized under solvothermal conditions. The complexes have been characterized by elemental analyses, IR spectroscopy and single-crystal X-ray diffraction. Complex 1 possesses 3D 2-fold interpenetrating nets with the Schläfli symbol {65·8}. Complex 2 consists a 3D net with the Schläfli symbol {44·610·8}. The luminescent properties of complexes 1 and 2 have been investigated.

Five Dinuclear Lanthanide Complexes Based on 2,4-dimethylbenzoic Acid and 5,5'-dimethy-2,2'-bipyridine: Crystal Structures, Thermal Behaviour and Luminescent Property.

A series of new complexes, [Ln (2,4-DMBA)3(5,5′-DM-2,2′-bipy)]2 (Ln = Sm(1), Eu (2)), [Pr (2,4-DMBA)3 (5,5′-DM-2,2′-bipy)]2·0.5(C2H5OH) (3), [Ln (2,4-DMBA)3 (5,5′-DM-2,2′-bipy)]2·0.5(2,4-DMBAH)·0.25(5,5′-DM-2,2′-bipy) (Ln = Tb (4), Dy (5)) (2,4-DMBA = 2,4-dimethylbenzoate, 5,5′-DM-2,2′-bipy = 5,5′-dimethy-2,2′-bipyridine) were synthesized via hydrothermal reaction conditions. The complexes were characterized through elemental analysis, Infrared spectra (IR), Raman (R) spectra, UV-Vis spectra, single X-ray diffraction. Single crystal data show that complexes 1–5 are binuclear complexes, but they can be divided into three different crystal structures. The thermal decomposition mechanism of complexes 1–5 were investigated by the technology of simultaneous TG/DSC-FTIR. What’s more, the luminescent properties of complexes 1–2 and 4 were discussed, and the luminescence lifetime (τ) of complexes 2 and 4 were calculated.

Luminescent properties of complexes and polymers of Sm (III)

The β-diketonate complexes of Sm(III) (SmL 3 . 2H 2 O) , heteroligand complexes with phenanthroline and dipyridyl ( SmL 3 . Phen, SmL 3 . Dipy ) where L = 2-methyl-5-phenyl-1-penten-dione-3,5 (mphpd), 2-methyl-5-biphenylpentene-1-dione-3,5 (mbphpd) were synthesized. The complexes were fully characterized using FTIR and thermal analyses. Absorption, diffuse reflectance and emission spectra for the complexes were recorded. The relationship between complex structure and the intensity of fluorescence emission was established. • Sm (III) complexes offer facile routes and novel materials for light emitting applications. • Novel β-diketonate and heteroligand complexes with samarium have been synthesized and characterized. • The relationship between structural and optical properties was clearly evidenced.

Terbium(III) as a Fluorescent Probe for Molecular Detection of Ascorbic Acid

Fluorescence analysis is a simple and a highly sensitive method for detection of small amounts of biologically active substances. In this study, a complexation of terbium(III) chelates with 1,10-phenanthroline and ascorbic acid (AA) and luminescent properties of complexes were investigated. The influence of pH and solubilization of complexes by micellar solutions of nonionic, cationic, and anionic surfactants on fluorescence was studied. The quenching effect of terbium ion fluorescence was detected upon an introduction of ascorbic acid. The quenching effect of the complex with mixed ligands Tb(1,10-phenanthroline)-AA allows for the detection of ascorbic acid with the limit of 7.4 × 10−5 mol·L−1.

Luminescent Properties of Complexes of Tellurium(IV) Halides with Pyridine (C5H5NH)2TeHal6 (Hal = Cl, Br)

Luminescent Properties of Complexes of Tellurium(IV) Halides with Pyridine (C5H5NH)2TeHal6 (Hal = Cl, Br)

Crystal exploring, Hirshfeld surface analysis, and properties of 4′‐(furan‐2‐yl)‐2,2′:6′,2″‐terpyridine complexes of nickel (II): New precursors for the synthesis of nanoparticles

A series of mono‐ and bis‐terpyridine complexes of nickel (II) based on the 4′‐(furan‐2‐yl)‐2,2′:6′,2″‐terpyridine (ftpy) have been synthesized and structurally characterized using elemental analysis, infrared spectroscopy, and single crystal X‐ray diffraction. The reaction of NiCl2•6H2O with ftpy has been resulted in the formation of new bis‐terpyridine complex [Ni (ftpy)2](PF6)•2H2O (1). The new complex [Ni (ftpy)2](PF6)2 (2), obtained during the crystallization of 1 in methanol, was characterized using X‐ray crystallography, which shows that six nitrogen atoms from terpyridine ligands occupy the coordination sites around the Ni (II) in a distorted octahedral geometry. On the other hand, the reaction of NiCl2•6H2O with ftpy in a 1:2 or 1:1 mole ratio in methanol in the presence of KSCN affords two new thiocyanato complexes [Ni (ftpy)2](SCN)2•2H2O (3) and [Ni (ftpy)(NCS)2(H2O)]•2H2O (4), respectively. The crystal structure of 3 reveals that nickel (II) is hexa‐coordinated in a distorted octahedral geometry NiN6 involving six atoms of two ftpy ligand; the ftpy ligands are perpendicular to each other. The new complex [Ni (ftpy)(NCS)2(DMSO)]•DMSO (5) is obtained during the crystallization of 4 in DMSO. The crystal structure of 5 reveals that the nickel (II) is hexa‐coordinated by three nitrogen atoms of ftpy, two NCS−, a DMSO in a slightly distorted octahedral geometry. The X–H (XH, C, N, O) bond interactions control the arrangement of the supramolecular 3D framework. Hirshfeld surface analyses and two‐dimensional fingerprint plot reveal that the main interactions are H–H contacts for 2, 3, and 5, which comprise 34.1%, 37.2%, and 34.6%, respectively. Thermal decomposition of the coordination complexes led to the formation of Ni, NiO, and Ni2P2O7 nanoparticles (NPs). The resulting NPs were fully characterized by powder XRD, field emission scanning electron microscopy (FESEM), transmission electron microscope (TEM), and energy‐dispersive X‐ray spectroscopy (EDX). The formation of these NPs indicates the role of the precursor complexes and counterion. Our results indicate that the NPs with the smaller size could be obtained at calcination temperature of 600 °C. Thermal and luminescent properties of complexes have been discussed in detail.

Preparation and optical features of samarium(III) complexes introducing bidentate fluorinate and secondary ligands

The syntheses of five luminescent samarium(III) complexes based on 6-Fluoro-4-oxo-4H-1-benzopyran-3-carboxaldehyde (L) and bidentate ancillary ligands were reported. The bidentate ancillary ligands were 1, 10-phenanthroline, 2, 2′-bipyridine, neocuproine, and bathophenanthroline. The complexes were characterized by employing elemental analysis, UV, FTIR, ESI–MS+ spectrometry, TGA, FESEM, and PXRD. The luminescence properties of complexes in solution and powder state have been discussed to investigate optical characterization. The complexes display characteristic luminescence peaks of samarium(III) ion at ~ 566, 600, and 647 nm. Different coordination environments around samarium(III) ion in dimethyl sulfoxide solution and powder state result in different emission colors: bright orange and red color with intense peaks at ~ 600 nm and ~ 647 nm. The luminescent quantum yield, decay time, CCT, and CIE coordinates were considered. The replacement of aqua ligands by the bidentate subsidiary ligands from the parent complex enriched emission properties, thermal stability, decay time, and quantum yields. Interesting optical properties of complexes in the orange-red spectral region might be useful in electronic devices, bio-assays, and liquid lasers.

Synthesis and structural characterization of a three-dimensional two-fold interpenetrated coordination polymer constructed from bis(4-(1H-imidazol-1-yl)phenyl)methanone and 1,1ʹ-biphenyl-2,2ʹ-dicarboxylate ligands for cadmium(II)

Abstract A three-dimensional (3D) two-fold interpenetrated coordination polymer, {[Cd(bipmo)(bpda)]·1.25(H2O)} n (1), (bipmo = bis(4-(1H-imidazol-1-yl)phenyl)methanone, H2bpda = 1,1ʹ-biphenyl-2,2ʹ-dicarboxylic acid), was synthesized by a solvothermal method. It has been characterized by elemental analyses, infrared (IR) spectroscopy, and single-crystal X-ray diffraction. The topological structure of 1 consists of uninodal dia nets with two-fold penetration. The thermal stability and the luminescence properties of complex 1 were investigated.

Effect of Substituents on the Crystal Structures, Optical Properties, and Catalytic Activity of Homoleptic Zn(II) and Cd(II) β-oxodithioester Complexes.

Five novel zinc(II) and cadmium(II) β-oxodithioester complexes, [Zn(L1)2] (1), [Zn(L2)2]n (2), [Zn(L3)2]n (3) [Cd(L1)2]n (4), [Cd(L2)2]n (5), with β-oxodithioester ligands, where L1 = 3-(methylthio)-1-(thiophen-2-yl)-3-thioxoprop-1-en-1-olate, L2 = 3-(methylthio)-1-(pyridin-3-yl)-3-thioxoprop-1-en-1-olate, and L3 = 3-(methylthio)-1-(pyridin-4-yl)-3-thioxoprop-1-en-1-olate, were synthesized and characterized by elemental analysis, IR, UV-vis, and NMR spectroscopy (1H and 13C{1H}). The solid-state structures of all complexes were ascertained by single-crystal X-ray crystallography. The β-oxodithioester ligands are bonded to Zn(II)/Cd(II) metal ions in an O∧S and N chelating/chelating-bridging fashion leading to the formation of 1D (in 2-4) and 2D (in 5) coordination polymeric structures, but complex 1 was obtained as a discrete tetrahedral molecule. Complex 4 crystallizes in the C2 chiral space group and has been studied using circular dichroism (CD) spectroscopy. The multidimensional assemblies in these complexes are stabilized by many important noncovalent C-H···π (ZnOSC3, chelate), π···π, C-H···π, and H···H interactions. The catalytic activities of 1-5 in reactions involving C-C and C-O bond formation have been studied, and the results indicated that complex 3 can be efficiently utilized as a heterogeneous bifunctional catalyst for the Knoevenagel condensation and multicomponent reactions to develop biologically important organic molecules. The luminescent properties of complexes were also studied. Interestingly, zinc complexes 1-3 showed strong lumniscent emission in the solid state, whereas cadmium complexes 4 and 5 exhibited bright luminescent emission in the solution phase. The semiconducting behavior of the complexes was studied by solid-state diffuse reflectance spectra (DRS), which showed optical band gaps in the range of 2.49-2.62 eV.

Heterochiral or Homochiral Self‐Assembly: Mercury(II), Cadmium(II), and Spontaneous Resolution of Silver(I) Complexes Derived from a Racemic Bis(pyridyl) Ligand

A novel racemic bis(pyridyl) ligand (rac‐L) was designed and synthesized by Schiff condensation reaction. Five complexes, [Hg2(LR)(LS)Cl4]·2CH3CH2OH (1), [Cd(LR)(LS)Cl2]n (2), {[Cd(LR)(LS)SO4(H2O)]·11H2O}n (3), {[Ag(LR)2]NO3·CH3CN}n (4a) and {[Ag(LS)2]NO3·CH3CN}n (4b) have been synthesized and characterized. The different geometric features of complexes 1–4 were determined by single‐crystal X‐ray diffraction. The crystal structures show that the self‐assembly with racemic ligands can lead to homochiral or heterochiral complexes, through self‐recognition or self‐discrimination of the ligand units. Complex 1 exists as a 26‐membered binuclear heterochiral macrocycle. Complexes 2 and 3 form 1D mesomeric looped chain coordination polymers with different heterochiral self‐assembly types. More interestingly, two novel 2D homochiral coordination polymers 4a and 4b were obtained as racemic conglomerates via spontaneous resolution. Furthermore, the thermal stabilities and luminescence properties of complexes 1–4 were investigated.

Preparation and Characterization of a Novel Terbium Complex Coordinated with 10-Undecenoic Acid for UV-Cured Coatings

A UV-cured composite containing a rare earth complex was prepared for this study. First, the photoluminescent terbium complex was synthesized with a long-chain unsaturated fatty acid (10-Undecenoic acid) by a solution precipitation method, resulting in the 10-UA-Tb(III) complex. Its structure was proven by FTIR, elemental analysis, XRD, and TGA. The results indicated that the organic acid ligand successfully coordinated with the Tb3+ ion and that the complex had a chelate bidentate structure. The emission spectrum of the 10-UA-Tb(III) complex indicated that the complex can emit a bright green light with the unique luminescence of the Tb3+ ion. Furthermore, the luminescence properties of complexes with different ratios of Tb3+ and ligand were studied, and the ratio of Tb3+ and the ligand had an obvious impact on the luminescence intensity of the 10-UA-Tb(III) complex. Subsequently, the prepared rare earth complex was doped into a UV-cured coating in different proportions to obtain a UV-cured composite. The morphology of the rare earth UV-cured composite was observed by SEM. The images showed that the rare earth complex was dispersed uniformly in the polymer matrix. Moreover, the composites could emit fluorescence. Additionally, it has good thermal stability and compatibility with the resin. Therefore, these composites should have potential applications in UV curable materials, such as luminescence coatings.

Three lanthanide–nitronyl nitroxide complexes: Syntheses, crystal structures, magnetic properties and fluorescence of selective sensing of Fe (III) ions

Three new lanthanide-nitronyl nitroxide radical complexes [Ln(hfac)3(NIT-biPh)2](Ln = Gd 1, Tb 2, Dy 3) (hfac = hexafluoroacetylacetonate; NIT-biPh = 2-([1,1′-biphenyl]-4-yl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) have been successfully synthesized and characterized. The X-ray crystal structure analysis revealed that three complexes are isomorphous, which exhibiting a mononuclear tri-spin structure. The central Ln (III) ion is eight-coordinated by six oxygen atoms from three hfac ligands and two oxygen atoms from the NO groups of two NIT-biPh ligands. The variable-temperature magnetic susceptibility indicated that ferromagnetic exchange interactions between the coordinated NO groups of radicals and Gd(III) ions, while antiferromagnetic exchange couplings between radicals within complex. Ac magnetic susceptibility exhibited no magnetic relaxation behavior at low temperature in compound 2. In addition, the luminescence properties of complex 2 show the characteristic emission peaks of Tb(III) ions and indicate an excellent fluorescent probe of recognizing Fe3+ ion.

Synthesis, structure and properties of a one-dimensional Cd(II) complex based on a chiral ligand

A new 1D Cd(II) complex [Cd(L-pheA)(Ac)]n (1) where the L-pheA– anion stands for the chiral ligand (L-phenylalanine hydroxamic acid) is synthesized and characterized. The single crystal X-ray analysis reveals that each Cd(II) atom is coordinated by three L-pheA– ligands and two acetate anions in a distorted seven-coordinated pentagonal bipyramidal configuration. By the interactions of two N—H⋯O and one N—H⋯N hydrogen bonds a 2D supramolecular network is formed. The solid-state luminescent properties of complex 1 are observed.

Supramolecular structures, thermal decomposition mechanism and heat capacity of the novel binuclear Tb(III) and Dy(III) complexes with 2,3-dimethoxybenzoic acid and 5,5′-dimety-2,2′-bipyridine

Two novel binuclear lanthanide complexes [Tb(2,3-DMOBA)3(5,5′-DM-2,2′-bipy)]2·C2H5OH (1) and [Dy(2,3-DMOBA)3(5,5′-DM-2,2′-bipy)]2·C2H5OH (2) (2,3-DMOBA = 2,3-dimethoxybenzoate, 5,5′-DM-2,2′-bipy = 5,5′-dimety-2,2′-bipyridine) have been successfully synthesized and structurally validated by single-crystal diffraction. The results of single-crystal analyses indicate the complexes contains one free ethanol molecule, and each center Ln(III) is nine-coordinated, exhibiting a distorted monocapped square anti-prismatic coordination geometry. The two center Ln(III) are bound by four 2,3-DMOBA ligands, two of which are bridging bidentate and the other two are bridging–chelating. The adjacent binuclear complexes can form 1D supramolecular structure by a pair of alternating identical C–H···O hydrogen bonding interactions, which further form 2D sheet structures. The thermal behavior of these complexes is investigated by TG-DSC/FTIR. What is more, the heat capacities of the complexes 1–2 are measured by DSC at 259.15–346.15 K, and the result indicates that the heat capacity values of the complexes gradually increased with the increase in temperature. In addition, the thermodynamic functions values (HT − H298.15K) and (ST − S298.15K) of the complexes 1–2 are calculated according to the fitted polynomial equations and the thermodynamic equation. The luminescence property of complex 1 is studied.