Synthesis,Crystal Structure,and Physical Properties of a ­Barium(II) Benzene‐1, 2, 3‐tricarboxylic Acid Complex

A coordination polymer [Ba₁₂(btc)₈(H₂O)₂₃] ( 1 ) was obtained by self‐assembly of the corresponding metal carbonate with benzene‐1, 2, 3‐tricarboxylic acid ligand (H₃btc), and its structure was determined by single‐crystal X‐ray diffraction studies. The results revealed that complex 1 has a three dimensional structure. In 1 , the btc^3– anions adopt four different conformation and coordination modes. Bridging btc^3– anions and μ₂‐bridging water molecules connect Ba^II ions to generate a two dimensional layer. Further, μ₂‐bridging coordinated water molecules connect the Ba^II ions of neighboring layers to form a three dimensional structure. Additionally, the luminescent property and thermal stability of 1 were investigated.     

Synthesis,Crystal Structure,and Physical Properties of a Barium(II) p‐(Carboxyl‐methyloxy)‐benzenecarboxylic Acid Complex

A coordination polymer [Ba(pcmb)(H₂O)_2.5] ( 1 ) was obtained by self‐assembly of the corresponding metal carbonate with a flexible ligand, p‐(carboxyl‐methyloxy)‐benzenecarboxylic acid (H₂pcmb), and its structure was determined by single‐crystal X‐ray diffraction studies. The result revealed that complex 1 has a three‐dimensional structure, in which the barium(II) atom takes a distorted eight‐coordinate bicapped anti‐prism arrangement. The pcmb^2– anion acts as a μ₄‐bridge ligand, in which carboxylate groups adopt monodentate and μ₃‐η²:η¹‐bridging two different coordination models to generate a three‐dimensional network structure. The luminescence property and thermal stability of 1 were investigated.     

Zinc(II), Cadmium(II), and Mercury(II) Complexes with the 2, 2′‐Diamino‐4, 4′‐bithiazole (DABTZ) Ligand — Syntheses and X‐Ray Crystal Structure of [Hg(DABTZ)(SCN)2]

Reaction of the ligand 2, 2′‐diamino‐4, 4′‐bithiazole (DABTZ) with Zn(ClO₄)₂, CdCl₂, and Hg(SCN)₂ gives complexes with composition [Zn(DABTZ)₂](ClO₄)₂, [Cd(DABTZ)₂Cl₂], and [Hg(DABTZ)(SCN)₂]. The complexes were characterized by elemental analyses and infrared spectroscopy. The crystal structure of the [Hg(DABTZ)(SCN)₂] was determined by X‐ray crystallography. The complex is built up of a monomeric Hg(SCN)₂ unit with one 2, 2′‐diamino‐4, 4′‐bithiazole ligand coordinated to the Hg atom via the two N atoms giving rise to a five‐member chelate ring in a distorted tetrahedral environment. There is π‐π stacking interaction between the parallel aromatic rings belonging to adjacent chain as planar species in which the mean molecular planes are close to parallel and separated by a distance of ～ 3.5Å, close to that of the planes in graphite. The coordinated 2, 2′‐diamino‐4, 4′‐bithiazole molecule is involved in hydrogen bonding acting as hydrogen‐bond donors with N atoms from the SCN ligand as potential hydrogen‐bond acceptors. The hydrogen bonding yields infinite chains parallel to the crystallographic vectors a and b. Each molecule is bonded to three neighbours. Both amine H atoms are hydrogen bonded to N atoms.     

Synthesis,Crystal Structure and Photoluminescence Property of Zinc(II), Cadmium(II), and Lead(II) Complexes with Bidentate Ligand: 1‐(1‐Imidazolyl)‐4‐(imidazol‐1‐ylmethyl)benzene (IIMB)

Assembly of bidentate ligand 1‐(1‐imidazolyl)‐4‐(imidazol‐1‐ylmethyl)benzene (IIMB) with varied metal salts of Zn^II, Cd^II and Pb^II provide three new complexes, [Zn(IIMB)₂](ClO₄)₂·2H₂O ( 1 ), [Cd(IIMB)₂(SCN)₂] ( 2 ) and [Pb(IIMB)₂(SCN)](SCN) ( 3 ). Single crystal X‐ray diffraction studies revealed that complexes 1 and 2 display a similar one‐dimensional double stranded chain structure, while complex 3 is a slight distorted rhombohedral grid network with (4,4) topology. The results indicate that the coordination geometry of the metal ion and the counter anion have great impact on the structure of the complexes. In addition, the photoluminescence properties of ligand IIMB and complexes 1 – 3 were studied in the solid state at room temperature.     

Synthesis,Structures, and Properties of Cadmium(II) and Nickel(II) Coordination Polymers Based on a 4,4′‐Biphenyl‐Containing Ligand and Aliphatic Carboxylic Acids

The coordination polymers [Cd₂(bbmb)₂(L₁)(HL₁)_0.5(H₂O)]_n ( 1 ), [Cd₂(bbmb)₂(L₂)₂(H₂O) · (H₂O)]_n ( 2 ), and [Ni(bbmb)₂(L₃)]_n ( 3 ), were synthesized by the hydrothermal reaction of 4,4′‐bis(benzimidazol‐1‐ylmethyl)biphenyl (bbmb) with Cd^II/Ni^II ions in the presence of three flexible aliphatic acids [tricarballylic acid (H₃L₁), succinate (H₂L₂), and adipate (H₂L₃)]. Complexes 1 – 3 were structurally characterized by elemental analysis, IR spectroscopy and single‐crystal and X‐ray powder diffraction analyses. Complex 1 presents a 3D 3‐nodal (3,4,4)‐connected net with 3 , 4 , 4T78 topology, 2 exhibits a 3D network with 6⁶‐ dia topology, whereas 3 is a chain structure and further extended by hydrogen bonding interactions to form a 2D supramolecular network. Structural diversity of these complexes indicates that these frameworks could be tuned by the conformation of bbmb ligand and the different coordination modes of the aliphatic carboxylate co‐ligands. The thermal and fluorescence properties, the catalytic activities of complexes 1 – 3 in a Fenton‐like process were investigated.     

Two Coordination Polymers based on 2‐Ethyl‐1H‐imidazole‐4,5‐dicarboxylic Acid and 1,3‐Bis(4‐pyridyl)propane: Synthesis,Crystal Structures,and Photoluminescent Properties

Two coordination polymers, [Cd(Heidc)(bpp)]_n ( 1 ) and [Zn₃ (eidc)₂(bpp)(H₂O)₂] · 2H₂O}_n ( 2 ) (H₃eidc = 2‐ethyl‐4,5‐imidazole dicarboxylic acid, bpp = 1,3‐bis(4‐pyridyl)propane) were hydrothermally synthesized and characterized by elemental analysis, IR, spectroscopy single‐crystal X‐ray diffraction, and thermogravimetric analyses. Compound 1 features a 2D layer formed by C–H ··· π stacking interactions between adjacent chains, whereas compound 2 shows a 3D (8³)₂(8⁵.10)‐tfc framework constructed of the 2D (6,3) layer. The result demonstrates that the central metal atoms play a key role in governing the coordination motifs. Moreover, solid‐state properties such as thermal stabilities and photoluminescence of 1 and 2 were also investigated.     

Synthesis and Crystal Structure of Diaqua bis(4‐amino‐3‐methyl‐1, 2, 4‐triazol‐5‐thione)cadmium(II) Nitrate

The reaction of 4‐amino‐5‐methyl‐1, 2, 4‐triazol‐3(2H)‐thione (HAMTT, 1 ) with cadmium(II) acetate in ethanol leads to [Cd(η²‐AMTT)₂(H₂O)₂] ( 2 ); the reaction of 2 with nitric acid in ethanol produces the single‐crystals of [Cd(η²‐HAMTT)₂(H₂O)₂](NO₃)₂ ( 3 ). 2 and 3 have been characterized by IR, Raman, ¹H NMR spectroscopy and elemental analyses; furthermore, 3 has been determined by single‐crystal X‐ray diffraction studies. 3 crystallizes in the space group Pbcn, orthorhombic with the lattice dimensions at —80 °C; a = 1604.2(1), b = 895.6(1), c = 1266.5(3) pm, Z = 4, R₁= 0.0276, wR₂= 0.0722.     

Synthesis,Crystal Structure and Spectroscopic Properties of Bis(1‐(E)‐2‐formylpyridine semicarbazone)nickel(II) Diperchlorate Monohydrate

Pale‐green crystals of the title complex were prepared by reaction of 2‐formylpyridine semicarbazone (HCSpy) and nickel(II) perchlorate in boiling ethanol. The crystals are triclinic with the nickel ion in an octahedral arrangement, coordinated by two nitrogen atoms and one oxygen donor atom from each ligand molecule. The effect of coordination on bond lengths and angles was explored by comparison with the single‐crystal structure data of the free ligand HSCpy, which was collected as well. The assumed coordination mode was supported by ¹H and ¹³C NMR spectroscopic data. A detailed analysis of the electronic properties, including semi‐empirical quantummechanical calculations is presented. Furthermore, the data obtained from magnetic susceptibility and EPR measurements are in accordance with a low‐spin d⁸ nickel(II) complex.     

Synthesis,Characterization, and DNA Binding Studies of a Nickel(II) Complex Containing the 1,3‐Bis(1‐propylbenzimidazol‐2‐yl)‐2‐oxapropane

A complex of formula [Ni(pobb)₂](pic)₂, (pobb = 1,3‐bis(1‐propylbenzimidazol‐2‐yl)‐2‐oxapropane, pic = 2,4,6‐trinitrophenol), has been synthesized and structurally characterized by physico‐chemical and spectroscopic methods. The crystals crystallize in the monoclinic system, space group C2/c, a = 25.766(11) Å, b = 14.943(7) Å, c = 19.543(14) Å, α = 90°, β = 129.722(4)°, γ = 90°, Z = 4. The coordination environment around nickel(II) atom can be described as a distorted octahedral geometry. The interactions of the ligand pobb and the nickel (II) complex with calf thymus DNA (CT‐DNA) are investigated by using electronic absorption titration, ethidium bromide‐DNA displacement experiments and viscosity measurements. The experimental evidence indicated the compounds interact with calf thymus DNA through intercalation.     

Syntheses,Structures, Electrochemistry,and Electrocatalysis of Three Copper(II) Coordination Polymers constructed from 5‐[4‐(1H‐Imidazol‐1‐yl)phenyl]‐1H‐tetrazole

Three coordination polymers (CPs) based on the 5‐[4‐(1H‐imidazol‐1‐yl)phenyl]‐1H‐tetrazole ( HL ) ligand, namely, [Cu(μ₂‐ L )(μ₄‐pbda)(H₂O)] ( 1 ), [Cu₂(μ‐Hbtc)(H₂btc)(μ₃‐OH)(μ₄‐ HL )] ( 2 ) and [Cu₅(μ₃‐ L )(μ₄‐ L )(μ₃‐ip)(μ₃‐OH)(H₂O)₂] · 2H₂O ( 3 ) (H₂pbda = 1,4‐benzenedicarboxylic acid, H₃btc = 1,3,5‐benzenetricarboxylic acid, H₂ip = isophthalic acid) were hydrothermally synthesized and structurally characterized. Complex 1 represents “weave”‐type 2D layers consisting of wave‐like 1D chains and 1D straight chains, which are further connected by hydrogen bonds to form a 3D supramolecular structure. Complex 2 exhibits a uninodal (4)‐connected 2D layer with a point symbol of {4⁴ · 6²}, in which the L ligand can be described as μ₅‐bridging and the H₂btc^– ions display multiple kinds of coordination modes to connect Cu^II ions into 1D “H”‐type Cu‐H₂btc chains. In complex 3 , 2D Cu‐ L layers with two kinds of grids and 1D “stair”‐type Cu‐ip chains link each other to construct a 3D {4¹² · 6³} framework, which contains the pentanuclear subunits. Deprotonated degree and coordination modes of carboxylate ligands may consequentially influence the coordination patterns of main ligands and the final structures of complexes 1 – 3 . Furthermore, electrochemical behaviors and electrocatalytic activities of the title complexes were analyzed at room temperature, suggesting practical applications in areas of electrocatalytic reduction toward nitrite and hydrogen dioxide in aqueous solutions, respectively.     

Magnesium(II), Calcium(II), and Barium(II) Coordination Compounds Constructed by 1H‐Tetrazolate‐5‐acetic Acid Ligand

Reactions of H₂tza (H₂tza = 1H‐tetrazolate‐5‐acetic acid) with Mg(NO₃)₂ · 6H₂O, Ca(NO₃)₂ · 4H₂O, or Ba(NO₃)₂ with the presence of KOH under hydrothermal conditions, produced three new coordination compounds, [M(tza)(H₂O)₂] (M = Mg ( 1 ), Ca ( 2 ), Ba ( 3 )). These compounds were structurally characterized by elemental analysis, IR spectroscopy, and single‐crystal X‐ray diffraction. Compounds 1 and 3 display 2D structures, whereas 2 reveals a 1D structure with bridging tza ligand molecules as linkers. Furthermore, the luminescence properties of 1 – 3 at room temperature in the solid state were also investigated. The results show that the nature of metal ions play an important role in governing the molecular frameworks of 1 – 3 , and the strong coordinate abilities of carboxylate and tetrazolate group, endow tza with abundant coordination modes.     

A Porous Cadmium(II) Framework: Synthesis,Crystal Structure,Gas Adsorption,and Fluorescence Sensing Properties

The Cd^II compound, namely [Cd(Tppa)(SO₄)(H₂O)]_n ( 1 ) [Tppa = tris(4‐(pyridyl)phenyl) amine], was synthesized by the reaction of CdSO₄ · 8H₂O and Tppa under solvothermal conditions. Single crystal X‐ray diffraction analysis revealed that compound 1 features a 3D porous framework based on 1D inorganic –[Cd–SO₄–Cd]_n– chains. Topological analysis reveals that compound 1 represents a trinodal (3,4,6)‐connected topological network with the point symbol of {6.7²}₂{6⁴.7.10}{6⁴.7⁵.8⁴.10²}. Gas adsorption properties investigations indicate that compound 1 exhibits moderate adsorption capacities for light hydrocarbons at room temperature. Luminescencence property studies revealed that this Cd^II compound exhibits high fluorescence sensitivity for sensing of CS₂ molecule.     

Synthesis and Structure of a New Vanadium(IV)‐Cadmium(II) Compound with the Nitrilotriacetate Ligand: {(NH4)2[(VIVO)2(μ2‐O)(nta)2Cd(H2O)2]·H2O}n

A polymeric V^IV‐Cd compound, {(NH₄)₂[(V^IVO)₂(μ₂‐O)(nta)₂Cd(H₂O)₂]·H₂O}_n (H₃nta = nitrilotriacetic acid), has been prepared and characterized by single‐crystal X‐ray diffraction. The compound crystallizes in the monoclinic space group C2/c with a = 17.3760(2) Å, b = 8.0488(1) Å, c = 17.3380(2) Å, β = 107.9690(10)°, V = 2306.55(5) ų, Z = 4, and R₁ = 0.0303 for 1958 observed reflections. The structure exhibits a heterometallic three‐dimensional network formed by polymeric [(V^IVO)₂(μ₂‐O)(nta)₂Cd(H₂O)₂]^2? anions.     

Synthesis,Crystal Structure,and DNA‐Binding Properties of a New Cd(II) Complex Involving 2‐(2‐1H‐Imidazolyl)‐1H‐Imdazolium Ligand

A new Cd(II) complex of Cd(H₃biim)₂(NCS)₂Cl₂ [H₃biim=2‐(2‐1H‐imidazolyl)‐1H‐imidazolium] was synthesized and characterized by elemental analyses, FT‐IR and X‐ray single crystal diffraction. In the X‐ray crystallography structure, the cadmium(II) ion is coordinated by two nitrogen atoms of two 2‐(2‐1H‐imidazolyl)‐ 1H‐imdazolium, two nitrogen atoms of two thiocyanate ions and two Cl^?. The interaction of the complex with calf thymus DNA was investigated through electronic absorption spectroscopy, fluorescence spectroscopy, viscosity measurement, cyclic voltammetry and gel electrophoresis. These results show that the Cd(II) complex can electrostatically bind to the phosphate group of DNA backbone. Interestingly, we found that the complex can cleave the pBR322 DNA at pH=7.2 and 37°C.     

Synthesis,Crystal Structure,DNA‐binding Properties and Antioxidant Activity of a Copper(II) Complex with Naphthalimide Schiff Base

The Schiff N‐allylamine‐4‐(ethylenediamine‐5‐methylsalicylidene)‐1,8‐naphthalimide (H₂L) and its copper(II) complex, [Cu(HL)₂] · 0.5DMF, were synthesized and characterized. The crystal structure of the Cu^II complex reveals a slightly distorted square‐planar arrangement provided by two N and O donors from two deprotonated ligands. In addition, the DNA‐binding properties of the ligand and Cu^II complex were investigated by fluorescence spectra, electronic absorption, and viscosity measurements. The experimental studies of the DNA‐binding properties indicated that the ligand and Cu^II complex reacted with DNA via intercalation binding mode, and binding affinity for DNA takes the order: ligand > Cu^II complex. The antioxidant assay in vitro suggested that both exhibited potential intensely antioxidant properties, and the ligand is more effective than its Cu^II complex.     

Crystal Structures and Photoluminescence Properties of Zinc(II) and Cadmium(II) Coordination Polymers with “Y”‐Shaped Ligands

Three Zn^II and Cd^II complexes with Y‐shaped dicarboxylate ligands, namely [Zn(L₁)(2,2′‐bpy)₂(H₂O)] · 2H₂O ( 1 ), [Zn(L₁)(bpp)(H₂O)] ( 2 ), and [Cd(L₁)(H₂O)] · H₂O ( 3 ) [H₂L₁ = N‐phenyliminodiacetic acid, 2,2′‐bpy = 2,2′‐bipyridine, bpp = 1,3‐bis(4‐pyridyl)propane] were synthesized and characterized by elemental analysis, IR spectroscopy single‐crystal X‐ray diffraction, and thermogravimetric analyses. Compound 1 shows an hydrogen‐bonded 2D network, whereas compound 2 is an infinite 1D wavy chain structure, though O–H ··· O hydrogen‐bonded to form a 2D network. Compound 3 displays a 2D uninodal 3‐connected Shubnikov plane net with the point symbol of (4.8²). Moreover, the solid‐state such as thermal stabilities and fluorescence properties of 1 – 3 were also investigated.     

Synthesis and Solid‐state Reaction of 1‐[3′‐(Benzotriazol‐2″‐yl)‐4′ ‐hydroxybenzoyl]‐3‐methyl‐5‐pyrazolones

A new kind of UV stabilizers, 1‐(3′‐(benzotriazol‐2″‐yl)‐4′‐hydroxy‐benzoyl)‐3‐methyl‐5‐pyrazolones (1a‐d), was synthesized with the aim to bind them chemically to certain polymers. The reaction of 1d with substituted benzaldehydes 4 in the molten state at 150°C and in the solid state at room temperature produced the condensation products l‐(3′‐(5″‐chlorobenzotriazol‐2″‐yl)‐4′‐hydroxyl‐5′‐chlorobenzoyl)‐3‐methyl‐4‐arylmethylene‐5‐pyrazolones (2) and 4,4′‐arylmethylene‐bis [1‐(3′‐(5″‐chloro‐benzotriazol‐2″‐yl)‐4′‐hydroxy‐5′‐chloro‐benzoyl)‐3‐methyl‐5‐pyrazolone] s (3), respectively, as the major product. On the other hand, the reaction of 1d with 4 at 50°C in chloroform solution proceeded non‐selectively to give a mixture of 2 and 3.     

Solvothermal Syntheses,Crystal Structures,and Luminescent Properties of Two New Cadmium(II) Coordination Polymers Based on Rigid / Flexible Dicarboxylate and N,N′‐Bis(4‐pyridyl)‐1,4,5,8‐naphthalenetetracarboxydiimide

In order to investigate the effect of the organic ligands on the structures of coordination polymers, two new cadmium(II) coordination polymers based on the different dicarboxylate ligands, namely [Cd₂(bpdc)₂(DPNDI)₂] · 3H₂O · NMF ( 1 ) and [Cd(obb)(DPNDI)] ( 2 ) [H₂bpdc = biphenyl‐4,4′‐dicarboxylate, H₂obb = 4,4′‐oxybis(benzoic acid), DPNDI = N,N′‐bis(4‐pyridyl)‐1,4,5,8‐naphthalene tetracarboxydiimide, and NMF = N‐methylformamide), were synthesized under solvothermal condition and further characterized. Complex 1 shows a twofold interpenetrated pcu topology. Complex 2 possesses a two‐dimensional (2D) layer structure with –ABCD– stacking sequence. Furthermore, the luminescent properties of complexes 1 and 2 are investigated.     

Synthesis,Characterization and Crystal Structure of the Dimeric Silver(I) Complex containing 4‐Amino‐5‐methyl‐2H‐1,2,4‐triazole‐3(4H)‐thione

The reaction of 4‐amino‐5‐methyl‐2H‐1,2,4‐triazole‐3(4H)‐thione (AMTT, 1 ) with AgNO₃ and triphenylphosphane in a molar ratio 1:1:2 in ethanol led to the dimeric complex {[Ag(AMTT)(PPh₃)₂]NO₃}₂·4EtOH ( 2 ). 2 was characterized by elemental analyses, IR, ³¹P NMR spectroscopy as well as single crystal X‐ray diffraction. Crystal data for 2 at ?80 °C: space group with a = 1265.5(2), b = 1300.9(2), c = 1509.5(2) pm, α = 83.77(2)°, β = 79.22(2)°, γ = 62.89(2)°, Z = 2, R₁ = 0.0330.     

Synthesis,Characterization, and Crystal Structure of a Chromium(III)‐Complex Containing 2,6‐Pyridinedicarboxylic Acid and 1,10‐Phenanthroline

The reaction of solution 2,6‐pyridinedicarboxylic acid and 1,10‐phenanthroline ( 1 ) with CrCl₃·6H₂O led to the complex [Cr(phen)(pydc)(H₂O)][Cr(pydc)₂]·4H₂O ( 2 ) (phen is 1,10‐phenanthroline and pydcH₂ is 2,6‐pyridinedicarboxylic acid). 2 was characterized by elemental analysis, IR spectroscopy and single‐crystal structure determination. Crystal data for 2 at ?80 °C: triclinic, space group , a = 818.5(1), b = 1492.2(1), c = 1533.6(2) pm, α = 76.45(1)°, β = 84.22(1)°, γ = 77.99(1)°, Z = 2, R₁ = 0.0416.