Synthesis, spectroscopic, and thermal investigation of transition and non-transition complexes of metformin as potential insulin-mimetic agents

Complexes of [Mn(MF)₂(Cl)₂]·2H₂O (1), [Fe(MF)₂(Cl)₂]Cl·4H₂O (2), [Ni(MF·HCl)₂(Cl)₂]·6H₂O (3), [Cu(MF·HCl)₂(Cl)₂] (4), [Zn(MF·HCl)₂](NO₃)₂·6H₂O (5), [Cd₂(MF·HCl)(Cl)₄(H₂O)] (6), [Mg(MF·HCl)₂(Cl)₂]·6H₂O (7), [Sr₂(MF·HCl)(Cl)₄(H₂O)] (8), [Ba(MF·HCl)₂(Cl)₂]·2H₂O (9), [Pt(MF)₄] (10), [Au(MF)₃]Cl₃ (11), and [Pd(MF)₂]Cl₂ (12) were synthesized from Legitional behavior of metformin drug as a diabetic agent. The authenticity of the transition and non-transition metal complexes were characterized by elemental analyses, molar conductivity, (infrared, UV–Vis) spectra, effective magnetic moment in Bohr magnetons, electron spin resonance, thermal analysis, X-ray powder diffraction as well as scanning electron microscopy. Infrared spectral studies as well as elemental analyses revealed the existence of metformin in the base or hydrochloride salt forms in the chelation state acts as a bidentate ligand while the platinum(IV) complex is coordinated through the deprotonation of –NH group. The magnetic and electronic spectra of Mn(II), Fe(III), Ni(II), and Cu(II) complexes suggest an octahedral geometry. Antimicrobial screening of metformin and its complexes were determined against the (G⁺ and G^?) bacteria (Escherichia coli, Staphylococcus aureus, Bacillus subtilis, and Pseudomonas aeruginosa) and fungi (Aspergillus flavus and Candida albicans).     

Synthesis, Spectral and Thermal Analyses of Novel Bi- and Polyhomonuclear Complexes of Pyrimidine Bisazo-dianil Derivatives

Seven new bi‐ and polyhomonuclear transition metal complexes with three polyhydroxlated bisazodianil ligands were synthesized and characterized. The ligands were derived from condensation of 6‐(5‐formyl‐2‐hydroxyphenylazo)‐2,4‐dihydroxypyrimidine with aliphatic diamines (H₈L¹, H₈L² and H₆L³). The data of elemental and thermal analyses, molar conductance measurement, IR, electronic and ESR spectra as well as magnetic moment measurements support the formation of [L¹Co₇Cl₆(H₂O)₁₀]·22H₂O ( 1 ), [H₂L²Mn₆Cl₆(H₂O)₈]·3H₂O·2EtOH ( 3 ), [L²Co₈Cl₈(H₂O)₁₂]·24H₂O ( 4 ), [H₄L³Co₂Cl₂(H₂O)₂]·8H₂O·2EtOH ( 6 ) with a tetrahedral geometry and [H₂L¹Ni₅Cl₄(H₂O)₁₆]·19H₂O·EtOH ( 2 ), [L²Ni₈Cl₈(H₂O)₂₈]·8H₂O·EtOH ( 5 ) with an octahedral geometry while [H₆L³Cu₃(H₂O)₇]Cl₃·10H₂O ( 7 ) has a distorted tetrahedral arrangement. The mode of bonding between the metal ions and the ligand molecules is determined and the metal‐metal interaction was studied. The activation thermo‐kinetic parameters for the thermal decomposition steps of the complexes E*, ΔH*, ΔS*, and ΔG* were calculated.     

Synthesis,spectroscopic, and antimicrobial study of Ca(II), Fe(III), Pd(II), and Au(III) complexes of amoxicillin antibiotic drug

Synthesis, spectroscopic characterization, theoretical and antimicrobial studies of Ca(II), Fe(III), Pd(II), and Au(III) complexes of amoxicillin (amox) antibiotic drug are presented in the current paper. Structure of 1: 1 (metal: amox) complexes were elucidated on the basis of elemental analyses, and IR, Raman, ¹H NMR, and electronic spectral data. According to molar conductance measurements the complexes had electrolyte nature. Amoxicillin reacted with metal ions as a tridentate ligand coordinated with metal ions via–NH₂,–NH, and β-lactam carbonyl groups. The complexes were formulated as [Ca(amox-Na)(H₂O)]·Cl₂·4H₂O (1), [Fe(amox-Na)(H₂O)₃]·Cl₃·3H₂O (2), [Pd(amox-Na)(H₂O)]·Cl₂ (3), and [Au(amox-Na)(H₂O)]·Cl₃ (4). Kinetic thermodynamic parameters (E*, ΔS*, ΔH*, and ΔG*) were calculated based on the Coats–Redfern and Horowitz–Metzger methods using thermo gravimetric curves of TG and DTG. Nanosize particles of amoxicillin complexes have been studied by XRD, SEM, and TEM methods. Theoretical studies of the synthesized complexes have been performed.     

Coordination assemblies of rigid–flexible 1,3-bis(5-(pyridine-2-yl)-1,2,4-triazole-3-yl)propane ligands with MCl<Subscript>2</Subscript> (M = Fe,Co, Cu or Zn): structural diversity and mass spectra

Reactions of the rigid–flexible N-heterocycle 1,3-bis(5-(pyridine-2-yl)-1,2,4-triazole-3-yl) propane (H₂L) with MCl₂ (M = Fe, Co, Cu or Zn) gave coordination complexes, {[Fe ₂ ^III Cl₄(H₂L)₂]·2Cl}·EtOH·H₂O (1), {[Co₃Cl₅(HL)]·H₂O} _n (2), {[Co₄Cl₄(H₂L)₂(H₂O)₄]·[CoCl₄]₂}·H₂O (3), [Cu₂Cl₃(HL)(H₂O)]₆·5H₂O (4), [Cu ₂ ^II Cu^ICl₄(HL)] _n (5), {[Zn₂Cl₂(L)H₂O]·H₂O} _n (6) and [Zn₄Cl₆(HL)₂] (7), which have been characterized by single-crystal X-ray diffraction. Structural analysis reveals that the pyridine triazole ligand attains versatile coordination modes in these complexes. Complexes 1, 3, 4 and 7 consist of 0D clusters with binuclear or tetranuclear units; complex 2 presents a 2D network accompanied by HL^? and chloride bridges; complexes 5 and 6 show 1D chains with [Cu₃] and [Zn₂] subunits. In addition, the electrospray ionization mass spectrometry properties of selected complexes were investigated, revealing the stabilities and structural states of these complexes in solution. These results indicate that H₂L is an excellent multiconnection linker for the construction of diverse coordination complexes.     

Spectroscopic and Solution Studies of Some Transition Metal Complexes of New 4-Hydroxy Coumarin Semi- and Thiosemicarbazone Complexes

Two new ligands, 4-hydroxy coumarin-3-thiosemicarbazone (H₂L¹) and 4-hydroxy coumarin-3-semicarbazone (H₂L²) were synthesized and used for the preparation of a series of transition metal complexes (Cr³⁺, Co²⁺, Ni²⁺, Cu²⁺, and Fe³⁺), derived from these ligands. These complexes have the forms [ML¹Cl₂]·nX (1–5) and [ML²Cl]·nX (6–9) (X = H₂O or ethanol). The structures of these complexes were elucidated by elemental analyses, IR, UV–Vis, and electrical conductivity, as well as magnetic susceptibility measurements and thermal analyses. IR spectral data indicates that in all complexes, the ligands act as monobasic tridentate, coordinated through keto oxygen or sulfur, azomethine nitrogen and deprotonated phenolic oxygen atom. On the basis of other physicochemical investigations, tetrahedral or square planar geometries are assigned for Cu²⁺ complexes in monomeric structures. In the case of the Co²⁺, Ni²⁺ and Fe³⁺ complexes, octahedral stereochemistries in monomeric structures are suggested. The dissociation constants of the ligands and the stability constants of their Cu(II), Co(II), Ni(II), and Fe(III) complexes have been also determined using potentiometric pH-metric titration in mixed solvents of dioxane: H₂O and DMF: H₂O with different ratios and different temperatures.     

Inclusion of Cl− or Br− anions within host framework formed by second-sphere interactions

In this study, we have deliberately utilized the second-sphere coordination approach into the construction of supramolecular inclusion solids Cl ? [H₂ L1]·[InCl₄] (Crystal I) and Br ? [H₂ L1]·[TeBr₆] (Crystal II). The chloride or bromine anions can be encapsulated inside the host assemblies formed by the diamine molecule (4,6-dimethyl-1,3-phenylene) bis(N,N-dibenzylmethane) (L1) and the metal complexes ([InCl₄]^? and [TeBr₆]^2?) via second-sphere interactions. The inclusion complexes have been structurally characterized by X-ray crystallography, indicating that weak C–H···Cl and C–H···Br hydrogen bonding synthons play a significant role in the construction of host framework. 2-D networks are formed in both complexes by the interconnection of 1-D networks through the multiple weak hydrogen bonding interactions with [InCl₄]^? or [TeBr₆]^2?. The guest Cl^? or Br^? anions are encapsulated inside the host cages through N–H···Cl hydrogen bonds. The inclusion selectively was studied for the two host assemblies.     

Molecular modeling,spectral, and biological studies of 4-formylpyridine-4 N-(2-pyridyl) thiosemicarbazone (HFPTS) and its Mn(II), Fe(III), Co(II), Ni(II), Cu(II), Cd(II), Hg(II), and UO2(II) complexes

The present work describes the preparation and characterization of some metal ion complexes derived from 4-formylpyridine-⁴ N-(2-pyridyl)thiosemicarbazone (HFPTS). The complexes have the formula; [Cd(HFPTS)₂H₂O]Cl₂, [CoCl₂(HPTS)]·H₂O, [Cu₂Cl₄(HPTS)]·H₂O, [Fe (HPTS)₂Cl₂]Cl·3H₂O, [Hg(HPTS)Cl₂]·4H₂O, [Mn(HPTS)Cl₂]·5H₂O, [Ni(HPTS)Cl₂]·2H₂O, [UO₂(FPTS)₂(H₂O)]·3H₂O. The complexes were characterized by elemental analysis, spectral (IR, ¹H-NMR and UV–Vis), thermal and magnetic moment measurements. The neutral bidentate coordination mode is major for the most investigated complexes. A mononegative bidentate for UO₂(II), and neutral tridentate for Cu(II). The tetrahedral arrangement is proposed for most investigated complexes. The biological investigation displays the toxic activity of Hg(II) and UO₂(II) complexes, whereas the ligand displays the lowest inhibition activity toward the most investigated microorganisms.     

Organic–inorganic hybrid complexes based on a Keggin-type polyoxoanion

Two organic?Cinorganic hybrid complexes based on a Keggin-type polyoxoanion, namely [Ni₂(H₂O)₂(bipy)₄(Hbipy)][AlW₁₂O₄₀]·7H₂O 1 and [Ni₂Cl₂(bipy)₃(Hbipy)₂][SiW₁₂O₄₀]·2.5H₂O 2 (bipy?=?4,4??-bipy), have been synthesized and characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, and single-crystal X-ray diffraction. Complexes 1 and 2 possess similar 2D layer structures, constructed from 1D zigzag chains {Ni(bipy)} _n ²ⁿ⁺ and alternatively arranged Keggin anion and bipy linkers. Photocatalytic investigations indicate that both 1 and 2 exhibit photocatalytic activity for the degradation of Rhodamine B.     

Structure and inclusion property of supramolecular host framework [H2 L1][XCl4], L1 = N,N,N′,N′-tetra-p-methoxybenzyl-ethylenediamine; X = Fe, Co, Pd

In this paper, we have used the hydrogen-bonding interactions, combining the designed diamine ligands and anionic metal chlorides, into the construction of a series of new pillar-layered supramolecular complexes. The flexible molecule N,N,N′,N′-tetra-p-methoxybenzyl-ethylenediamine (L1) bearing doubly protonated H-bond donors, has been synthesized and reacted with the metal chlorides (such as [PdCl₄]^2?, [FeCl₄]^? and [CoCl₄]^2?) via weak C–H···Cl interactions, yielding crystal products [H₂ L1]²⁺·Cl^?·[FeCl₄]^? (1), 0.5H₂O ? [H₂ L1]²⁺·Cl^?·0.5[PdCl₄]^2? (2) and [2-hydroxy naphthyl]_1.5 ? 2[H₂ L1]²⁺·2Cl^?·[CoCl₄]^2? (3). The 3-D networks are organic double layers formed by the self-assembly of the ligands through extensive hydrogen-bonding interactions (C–H···O or C–H···π interactions) and further interconnected by [PdCl₄]^2?/[FeCl₄]^?/[CoCl₄]^2? in a pillar fashion, constructing into pillar-layered networks with channels accessible to various guest molecules. The inclusion property of [H₂ L1][CoCl₄] was studied, varieties of guest molecules, such as 2-hydroxy naphthyl, phenanthrene and hydroquinone, can be included in the framework.     

Synthesis,spectral, antimicrobial,and thermal properties of Ce(III), Gd(III), Nd(III), Tb(III), and Er(III) gliclazide complexes

The complexation between the lanthanide metal ions Ce(III), Gd(III), Nd(III), Tb(III), and Er(III) and gliclazide produced 1 : 1 molar ratio metal: gliclazide (Glz) complexes coordinated in a monodentate fashion via the OH group and having the general formulas [M(Glz)Cl₃(H₂O)]·xH₂O (M = Ce, Gd, Nd and x = 1, 3, 4, respectively) and [M(Glz)(H₂O)₄]Cl₃·yH₂O (M = Tb, Er and y = 1, 2, respectively). The structure of the synthesized lanthanide gliclazide complexes was assigned by IR, ¹HNMR, and UV-Vis spectroscopy. Thermal analysis and kinetic and thermodynamic parameters gave evidence for the thermal stability of the Glz complexes. The latter showed a significant antimicrobial effect against some bacteria and fungi.     

Synthesis,crystal structures,and luminescent properties of three cluster-based heterometallic and monometallic compounds

Two heterometallic cluster compounds and one monometallic cluster compound, namely [Ni₉Co₆(PMIDA)₆(BTC)₂(H₂O)₁₂]·6H₂O (1), [Co₁₃Zn₂(PMIDA)₆(H₂O)₁₈]·6NO₃·15H₂O (2), and [Fe₁₅(PMIDA)₆(BTC)₂(H₂O)₂₂]·38H₂O (3), have been obtained under hydrothermal conditions using N-(phosphonomethyl)imino-diacetic acid (H₄PMIDA) and 1,3,5-benzenetricarboxylate acid (H₃BTC) as ligands, and structurally characterized by X-ray crystallography. Compound 1 exhibits a 3D open framework constructed from [Ni₉Co₆(PMIDA)₆(H₂O)₁₂]⁶⁺ heteronuclear clusters and BTC^3? ligands. Compounds 2 and 3 are both zero-dimensional polynuclear clusters, further extended into 3D supramolecular structures via hydrogen-bonding interactions. However, there are some differences in their crystal structures; compound 2 features an isolated spherical heteronuclear cation cluster based on PMIDA^4? ligands, such that the NO₃ ^? anions only balance the charge, whereas compound 3 is characterized as a neutral monometallic cluster incorporating two different types of organic acid ligands, namely PMIDA^4? and BTC^3?, and the two BTC^3? ligands exhibit regular distribution in each cluster. The luminescence properties of all three compounds have been investigated at room temperature.     

Synthesis and spectroscopic studies of 2,5-hexanedione bis(isonicotinylhydrazone) and its first raw transition metal complexes

New VO²⁺, Mn²⁺, Co²⁺, Ni²⁺ Cu²⁺ and Zn²⁺ complexes of 2,5-hexanedione bis(isonicotinylhydrazone) [H₂L] have been synthesized and characterized. The analyses confirmed the formulae: [VO(L)]·H₂O, [Mn₂(H₂L)Cl₂(H₂O)₆]Cl₂, [Co(L)(H₂O)₂]·2H₂O, [Ni(HL)(OAc)]·H₂O, [Cu(L)(H₂O)₂]·2H₂O, [Cu(L)]·2H₂O and [Zn(L)(H₂O)₂]. The formulae of [Ni(HL)(OAc)]·H₂O, [Zn(L)(H₂O)₂] and [Mn₂(H₂L)Cl₂(H₂O)₆]Cl₂, are supported by mass spectra. The molecular modeling of H₂L is drawn and showed intramolecular hydrogen bonding. The ligand releases two protons during reaction from the two amide groups (NHCO) and behaves as a binegative tetradentate (N₂O₂); good evidence comes from the ¹H NMR spectrum of [Zn(L)(H₂O)₂]. The ligand has a buffering range 10–12 and pK's of 4.62, 7.78 and 9.45. The magnetic moments and electronic spectra of all complexes provide a square-planar for [Cu(L)]·2H₂O, square-pyramidal for [VO(L)]·H₂O and octahedral for the rest. The ESR spectra support the mononuclear geometry for [VO(L)]·H₂O and [Cu(L)(H₂O)₂]·2H₂O. The thermal decomposition of the complexes revealed the outer and inner solvents where the end product in most cases is metal oxide.     

Infinite 1D water chains present in complexes of Co(II) and Zn(II) with 4,4′,6,6′-tetramethyl-2,2′-bipyrimidine

Two new transition metal complexes [Co(tmbpm)Cl₂(H₂O)]·2H₂O (1) and [Zn(tmbpm)Cl₂]·2H₂O (2) (where tmbpm = 4,4′,6,6′-tetramethyl-2,2′-bipyrimidine) are synthesized and characterized by IR and single crystal X-ray diffraction. The tmbpm adopts chelating coordination mode in the two mononuclear complexes. Both 1 and 2 form 2D supramolecular structures containing an infinite 1D water chain through hydrogen bonds.     

Interaction of uranyl monoaquadiformate with diaza-18-crown-6 in aqueous ethanol

The reaction of {[UO₂(HCOO)₂(H₂O)]} with diaza-18-crown-6 (DA18C6 = C₁₂H₂₆O₄N₂) in aqueous ethanol in the presence of formic acid yields the complexes {[DA18C6H₂]·[UO₂(HCOO)₃]₂} (I), [DA18C6H₂]·[UO₂(HCOO)₄] (II), and [DA18C6H₂]·(HCOO)₂·(H₂O)₂ (III). The complexes are characterized using IR spectroscopy, chemical analysis, and powder X-ray diffraction. From the comparison of the structural and spectral characteristics of [DA18C6H₂]·An₂·(H₂O)_2n (where An = Cl^?,NO ₃ ^? ,HCOO^?,HSO ₄ ^? ; n = 0.1), correlations are derived between the conformation of the [DA18C6H₂]²⁺ units and the conformation-sensitive frequencies. On the basis of these correlations, the conformations of the N⁺CCO and OCCO units were determined in the diazonia cations of compounds I and II and in [DA18C6H₂]·[UO₂(NO₃)₄]; the latter was prepared previously by reacting [UO₂(NO₃)₂(H₂O)₂]·(H₂O)₄ with DA18C6 in ethanol in the presence of nitric acid.     

Syntheses,crystal structures,and properties of three two-dimensional complexes constructed by flexible (2,3-pyridylmethyl)amine

Three two-dimensional coordination polymers [Cd(2,3-Pyma)Cl₂] _n (I), {[Cd(2,3-Pyma)(1,4-Chdc)] · 4H₂O}n (II) and {[Zn₂(2,3-Pyma)(1,2,4,5-Bttc)(H₂O)₄] · 6H₂O} _n (III) (2,3-Pyma = (2,3-pyridylmethyl) amine, H₂-1,4-Chdc = 1,4-cyclohexanedicarboxylic acid, and H₄-1,2,4,5-Bttc = 1,2,4,5-benzenetetracarboxylic acid) have been synthesized and structurally characterized by single crystal X-ray crystallography (CIF files CCDC nos. 989461 (I), 1055685 (II) and 1055686 (III)). Three complexes are all twodimensional layer networks bridged by the flexible 2,3-Pyma ligands or the carboxylate ligands. It is noted that the flexible 1,4-Chdc ligands bind the Cd²⁺ ions into a helical chain structure in complex II. The photoluminescence and thermal properties are investigated.     

Syntheses, crystal structures and properties of three novel coordination polymers with tripodal imidazole-containing ligands and benzenetetracarboxylate

Three novel coordination polymers, [Ni₂(tib)₂(btec)]·2H₂O (1), [Co₂(tib)₂(btec)]·2H₂O (2) and [Zn₄(tib)₂(btec)Cl₄]·2H₂O (3), have been synthesized by using mixed ligands of 1,3,5-tris(1-imidazolyl)benzene (tib) and 1,2,4,5-benzenetetracarboxylic acid (H4btec) under hydrothermal conditions. Complexes 1 and 2 have the same structure and are rare three-dimensional (3D) self-penetrating (3,4,5)-connected nets, while complex 3 is an unprecedented (3,4)-connected 3D net. The different structures of 1 (2) and 3 are ascribed to the distinct coordination geometry of the metal centers. The thermal stability and photoluminescence property of the complexes were investigated.     

Homo- and heteronuclear iron complexes {Fe<Subscript>2</Subscript>MO} with salicylic acid: Synthesis,structures, and physicochemical properties

A reaction of iron nitrate with magnesium salicylate and reactions of iron and cobalt chlorides with ammonium salicylate in the presence of water, methanol, DMAA, and DMF gave the trinuclear heterometallic complexes: [hexa-μ-salicylato-μ₃-oxo-0.4-dimethylacetamide-2.6-aquadiiron(III)magnesium(II)] tetra(dimethylacetamide), [Fe₂MgO(SalH)₆(DMAA)_0.4(H₂O)_2.6]·4DMAA (I); [hexa-μ]-salicylato-μ₃-oxo(dimethanol)aquadiiron(III)cobalt(II)] dimethylformamide · 2.5-hydrate, [Fe₂CoO(SalH)₆(CH₃OH)₂(H₂O)] · DMF · 2.5H₂O (II); and [hexa-μ-salicylato-μ₃-oxotriaquatriiron(III)] chloride dimethylacetamide monohydrate, [Fe₃O(SalH)₆(H₂O)₃]Cl · DMAA · H₂O (III). The X-ray study revealed that the molecular structures of complexes I and II are [Fe₂ ^IIIM^II(μ₃-O)(RCOO)₆L₃] · nSolv. The IR and Mössbauer spectra of complexes I–III were examined; their magnetochemical and thermal properties were studied. The parameters of the Mössbauer spectra (δ_Na ⁺ = 0.69 ± 0.03 mm/s, ΔE _Q = 0.76–1.08 mm/s, 300 K) suggest the high-spin state of the Fe³⁺ ions in complexes I–III (S = 5/2). The paramagnetic Fe³⁺ ions are involved in antiferromagnetic exchange interactions with the parameter J = ?44 cm^?1, g = 2.05 (for I). Complexes I–III are thermally unstable.     

Oxo-Centered Trinuclear Chromium(III) Complexes with Both Carboxylate and Amidoximate Ligands

Compounds [Cr ₃ ^III (μ₃-O)(O₂CPh)₅(H₂N-sao)(EtOH)₂]·EtOH (1·EtOH) and [Cr ₃ ^III (μ₃-O)(O₂CPh)₃(H₂N-pao)₃]NO₃·H₂N-paoH·EtOH (2·NO₃·H₂N-paoH·EtOH) have been obtained either in a sequential one-pot, two-step procedure in which Cr(NO₃)₃·9H₂O is first reacted with sodium benzoate in ethanol under reflux, followed by the addition of salicylamidoxime (H₂N-saoH₂) or pyridine-2-amidoxime (H₂N-paoH), or in a one-step protocol starting from [Cr ₃ ^III (μ₃-O)(O₂CPh)₆(EtOH)₃]NO₃. They were characterized by single-crystal X-ray diffraction, magnetometry and EPR spectroscopy. Complexes 1 and 2 are derived from the parent complex [Cr ₃ ^III (μ₃-O)(O₂CPh)₆(EtOH)₃]⁺ by replacement of one and three benzoate ligands, respectively, by oximate ligands. The salicylamidoximate and pyridine-2-amidoximate ligands display a tridentate coordination mode with the N–O oximate group bridging a pair of Cr atoms and the additional ligating atom substituting for an ethanol ligand of the parent complex. In both cases susceptibility, magnetization and EPR data reveal a S _T = 1/2 ground state with a nearly isotropic g-tensor.     

Three metal complexes based on tetrazolyl ligands: Hydrothermal syntheses,crystal structures,and fluorescence properties

Three new complexes based on 1-tetrazole-4-imidazole-benzene (Tibz), namely, [Cd(Tibz)₂(H₂O)₂] _n (I), [Mn(Tibz)₂(H₂O)₄] · 2H₂O (II) and [Co(Tibz)₂(H₂O)₄] · 2H₂O (III) have been synthesized through hydrothermal method and structurally characterized by element analyses, IR spectroscopy and single-crystal X-ray diffraction analyses (CIF files CCDC nos. 1443867 (I), 1443868 (II), 1443869 (III)). Single-crystal X-ray diffraction reveals that complex I is a 1D double-chain architecture, II and III are both mononuclear complexes. The results of single-crystal X-ray diffraction analyses indicate that the hydrogen bond and π··· π stacking exist in the complexes, which make great contribution to the stabilities of complexes I–III. The fluorescent properties of these complexes have also been studied in the solid state at room temperature.