Syntheses,crystal structures,and fluorescent properties of two d10 metal complexes based on 2-(benzoimidazol-yl)methyl)-1H-1,2,4-triazole and 1,3,5-benzenetricarboxylate

Two d¹⁰ metal complexes, {[Zn(Hbtc)(bmt)]·DMF·5H₂O} _n (1) and {[Cd(Hbtc)(bmt)]·0.5DMF·0.5H₂O} _n (2) (H₃btc?=?1,3,5-benzenetricarboxylic acid, bmt?=?2-((benzoimidazol-yl)methyl)-1H-1,2,4-triazole), have been synthesized under solvothermal conditions by employing bmt and H₃btc. Single-crystal X-ray diffraction shows that Zn(II) ions are connected by bmt with bidentate-bridging coordination and by 1,3,5-benzenetricarboxylate with bis-monodentate coordination leading to the 2D structure of 1. Complex 2 exhibits a 2D layer structure, in which bmt coordinate tridentate-bridging to Cd(II) and 1,3,5-benzenetricarboxylates coordinate to Cd(II) unidentate/chelating. Photoluminescence and thermogravimetric analyses of the two complexes are investigated.     

Syntheses,crystal structures,and photophysical properties of two 2-D coordination polymers

Two coordination polymers, [Mn(dipt)(m-BDC)₃] _n (1) and [Pb(mip)(1,4-NDC)] _n (2) [dipt?=?2-(2,4-dichlorophenyl)-1H-imidazo[4,5-f][1,10]phenanthroline, mip?=?2-(3-methoxyphenyl)-1H-imidazo[4,5-f][1,10]phenanthroline, m-BDC?=?isophthalic acid, 1,4-NDC?=?naphthalene-1,4-dicarboxylic acid], have been synthesized by hydrothermal reactions and characterized by elemental analysis, thermogravimetric analysis, infrared spectrum, and single-crystal X-ray diffraction. Single-crystal X-ray diffraction reveals that 1 and 2 have 1-D chain architecture. Complex 1 has a 2-D-layered structure constructed from C–H···O hydrogen bonds. Complex 2 has a 2-D-layered structure constructed from N–H···O hydrogen bonds and π–π interactions. TG analyses suggest 1 and 2 have excellent thermal stabilities from hydrogen bonds and π–π interactions. Mn(II) in 1 has trigonal bipyramidal geometry surrounded by three carboxylate oxygen atoms from three monodentate bridging m-BDC and two nitrogen atoms from one dipt. Pb(II) has [:PbN2O4] pentagonal bipyramidal geometry in 2. The luminescent properties for dipt, mip, 1, and 2 are also presented.     

Two coordination polymers based on 2,2′-biimidazoles and d10 metal ions: syntheses,structures, and luminescence

Two d¹⁰ metal coordination polymers, [Zn(µ-Me₂biim)Cl₂] _n (1) and [Cd₃(MeHbiim)₂(1,4-BDC)₃] _n (2) (Me₂biim?=?N,N′-dimethyl-2,2′-biimidazole, MeHbiim?=?N-methyl-2,2′-biimidazole, 1,4-BDC?=?1,4-benzenedicarboxylate), were synthesized under hydrothermal conditions and characterized by elemental analysis, infrared spectroscopy, thermogravimetric analysis, and single-crystal X-ray crystallography. Complex 1 features an infinite neutral zigzag 1-D chain. Interchain hydrogen-bonding interactions further extend the 1-D arrangement to generate a 2-D supramolecular architecture. Complex 2 features a 3-D coordination polymer with α-Po net topology, based on linear trinuclear {Cd₃O₁₄N₄} clusters. Both complexes have high thermal stability and exhibit strong luminescence at room temperature.     

Cyanide-bridged complexes based on dinuclear Cu(II)-M(II) [M = Pb and Cu] building blocks: Synthesis, crystal structures and magnetic properties

Four cyanide-bridged heterometallic complexes {[CuPb(L 1 )][Fe III (bpb)(CN) 2 ]} 2 ·(ClO 4 ) 2 ·2H 2 O·2CH 3 CN (1), {[CuPb(L 1 )] 2 [Fe II (CN) 6 ](H 2 O) 2 }·10H 2 O (2), {[Cu 2 (L 2 )][Fe III (bpb)(CN) 2 ] 2 }·2H 2 O·2CH 3 OH (3) and {[Cu 2 (L 2 )] 3 [Fe III (CN) 6 ] 2 (H 2 O) 2 }·10H 2 O (4) have been synthesized by treating K[Fe III (bpb)(CN) 2 ] [bpb 2-=1,2-bis(pyridine-2-carboxamido)benzenate] and K 3 [Fe III (CN)] 6 with dinuclear compartmental macrocyclic Schiff-base complexes [CuPb(L 1 )] (ClO 4 ) 2 or [Cu 2 (L 2 )]·(ClO 4 ) 2 , in which H 2 L 1 was derived from 2,6-diformyl-4-methyl-phenol, ethylenediamine, and diethylenetriamine in the molar ratio of 2:1:1 and H 2 L 2 from 2,6-diformyl-4-methyl-phenol and propylenediamine in the molar ratio of 1:1. Single crystal X-ray diffraction analysis reveals that compound 1 displays a cyclic hexanuclear heterotrimetallic molecular structure with alternating [FeⅢ (bpb)(CN) 2 ]- and [CuPb(L 1 )] 2+ units. Complex 2 is of a neutral dumb-bell-type pentanuclear molecular configuration consisting of one [Fe(CN)6] 4- anion sandwiched in two [CuPu(L 1 )] 2+ cations, and the pentanuclear moieties are further connected by the hydrogen bonding to give a 2D supramolecular framework. Heterobimetallic complex 3 is a tetranuclear molecule composed of a centrosymmetric [Cu 2 (L2)] 2+ segment and two terminal cyanide-containing blocks [FeⅢ (bpb)(CN)2 ]- . Octanuclear compound 4 is built from two [Fe(CN)6]3- anions sandwiched in the three [Cu 2 L 2 ] 2+ cations. Investigation of their magnetic properties reveals the overall antiferromagnetic behavior in the series of complexes except 2.     

Syntheses,structures and luminescent properties of four d-metal coordination polymers based on the 2,4,5-tri(4-pyridyl)-imidazole ligand

Four d¹⁰-metal coordination polymers based on the 2,4,5-tri(4-pyridyl)-imidazole ligand (Htpim), {[Zn₂(Htpim)₄Cl₄] · 8H₂O}_n (1), {[Cd(tpim)₂(H₂O)₂] · 4CH₃OH}_n (2), {[Cu₂(Htpim)(PPh₃)₂I₂] · CH₃CN}_n (3) and {[Ag(Htpim)](NO₃) · CH₂Cl₂}_n (4), have been synthesized and characterized by elemental analyses, IR, thermogravimetric and X-ray structural analyses. Both complexes 1 and 2 show one dimensional ribbon-like structures. Via intermolecular hydrogen bonds, a 2D supramolecular network and 3D framework are formed for 1 and 2, respectively. Complex 3 shows a 1D zigzag chain with a CuI₂Cu rhomboid dimer. Complex 4 shows a 1D ladder-like polymer with two different metallacycles. The luminescent properties of all the complexes have been studied in the solid state.     

Synthesis, crystal structures and fluorescence properties of four mixed-ligands Zn(Ⅱ) and Cd(Ⅱ) coordination compounds

Four new coordination compounds, [Zn(dba)(bpy)]n (1), {[Zn(dba)(phen)]·2H2O}n (2), [Cd(dba)(bpy)(H2O)2] (3) and [Cd2(dba)2(phen)2]n (4) (H2dba = 2,5-dihydroxy-p-benzenediacetic acid, bpy = 2,2′-bipyridine, phen = 1,10-phenanthroline) have been prepared via solvothermal method and characterized by sin-gle-crystal X-ray diffraction, infrared spectroscopy, elemental analysis and powder X-ray diffraction. 1 and 2 possess 1D infinite chain structures. Complex 3 exhibits a mononuclear structure. Complex 4 owns bi...     

Syntheses,crystal structures,and photophysical properties of two 2-D coordination polymers with different geometries of lead(II)

Two complexes constructed from aromatic acid and N-heterocyclic ligands have been synthesized by hydrothermal reaction: [Pb(cipt)(NDC)]_n (1) [cipt?=?2-(3-chlorophenyl)-1H-imidazo[4,5-f][1,10]phenanthroline, NDC?=?naphthalene-1,4-dicarboxylic acid] and [Pb(ipm)(BDC)₂]_n (2) [BDC?=?terephthalic acid, ipm?=?5-(1H-imidazo[4,5-f][1,10]phenanthrolin-2-yl)-2-methoxyphenol]. Single-crystal X-ray analysis shows that 1 exhibits an interesting arm-shaped chain structure. 1-D ladder chain structure is formed by N–H···O bonding interactions and further into a 2-D network by N–H···O hydrogen bonds and interchain π–π stacking interactions. Complex 2 shows a 2-D butterfly wings structure, which has been rarely reported. The structure in 2 has intermolecular N–H···O interactions, which help in construction of the 3-D framework. In 1, the coordination sphere of Pb(II) is hemi-directed, whereas the Pb(II) geometry in 2 is holo-directed. The solid-state fluorescence spectra of 1 and 2 are also investigated, as well as the ligands cipt and ipm.     

Complex Formation of 1,10-Dibenzyl-1,10-diaza-18-crown-6 with Ni2+, Cu2+, Ag+ and Cd2+ Metal Cations in Acetonitrile–dimethylformamide Binary Solutions

Conductance measurements are reported for nickel(II), cupper(II), silver(I) and cadmium(II), salts in acetonitrile (AN)–dimethylformamide (DMF) binary solvents containing macrocyclic ligand, 1,10-dibenzyl-1,10-diaza-18-crown-6 (DBDA18C6) at different temperatures. The changes in molar conductance caused by addition of DBDA18C6 to solutions were analyzed by non-linear least squares to give stability constants of 1:1 metal cation–DBDA18C6 complexes. The results show that the stabilities of the complexes are sensitive to solvent composition and in some cases the sequence of stabilities is changed with changing the composition of the mixed solvents. The values of thermodynamic quantities (ΔH°c and ΔS°c) for formation of DBDA18C6-Ni²⁺, DBDA18C6-Cu²⁺, DBDA18C6-Ag⁺ and DBDA18C6-Cd²⁺ complexes were obtained from temperature dependence of the stability constants and the results show that the values of ΔH°c and ΔS°c for these complexes are sensitive to the nature and composition of AN–DMF binary solutions, but they do not vary monotonically with the solvent composition.     

[Boranato-bis(dimethylphosphonium-methylid)]-Komplexe der do- und d10-Metalle: Li,Be, Mg,Zn, Cd,Hg, Al und Ga

Dehydrohalogenation and metallation of boranato-bis-trimethylphosphonium salts (1), using two equivalents of a lithiumalkyl in tetrahydrofuran, leads to a solvated organolithium reagent H₂B[(CH₃)₂PCH₂]₂Li (3) which can be converted into a 1:1n1-complex with tetramethylethylenediamin (4).3 reacts with anhydrous metal(II) halides to form spirocyclic coordination compounds of the type H₂B[(CH₃)₂PCH₂]₂ M[CH₂P(CH₃)₂]₂BH₂ (5–9,M=Be, Mg, Zn, Cd, Hg). The reaction of [(CH₃)₃PBH₂P(CH₃)₃]Br (1) with lithium tetramethylmetalates Li[M(CH₃)₄],M=Al, Ga, on heating in the absence of a solvent affords the metallocycles H₂B[(CH₃)₂PCH₂]₂ M(CH₃)₂ (10, 11) with evolution of methane. The products can be sublimed from the reaction mixture. The proposed structures of the new compounds, with tetrahedrally coordinated central atoms and strong covalent metal-carbon interactions, are supported by mass, IR and¹H,⁷Li,¹¹B,¹³C, and³¹P NMR spectra. Compound9 represents a rare case of a tetracoordinate organomercurial, compound5 is the first nonionic tetraalkylberyllate.

     

Synthesis,crystal structures and properties of two Cd(II) complexes based on Zaltoprofen

Abstract

Two metal-organic coordination complexes, [Cd(Zaltoprofen)(phen)]_n (1) and [Cd(Zaltoprofen)(btz)]_n (2) (where Zaltoprofen = 5-(1-carboxyethyl)-2-(phenylthio)phenylacetic acid, phen = 1,10-phenanthroline, btz = thiabendazole), have been synthesized by reaction of Cd(NO₃)₂ with Zaltoprofen, 1,10-phenanthroline or thiabendazole under hydrothermal conditions and characterized by single crystal X-ray diffraction, IR spectra, elemental analyses, powder X-ray diffraction (XRD), electronic spectra (UV-vis) and fluorescent properties. Compound 1 crystallizes in the monoclinic P21/c space group and 2 in the monoclinic system with space group P21/n. [Cd(Zaltoprofen)(phen)]_n (1) features a 1-D zigzag chain. The zigzag chains are linked to form a 2-D layer through π–π stacking interactions. [Cd(Zaltoprofen)(btz)]_n (2) displays a 2D net with alternately arranged left- and right-handed helical chains.     

Auxiliary aromatic-acid effect on the structures of a series of Zn coordination polymers: Syntheses, crystal structures, and photoluminescence properties

Five novel Zn^II-(pyridyl)imidazole derivative coordination polymers, [Zn(L)₂] (1), [Zn₂(μ₃-OH)L(m-BDC)] (2), [Zn₂(μ₃-OH)L(p-BDC)]·H₂O (3), [Zn₂L(BTC)(H₂O)]·2.5H₂O (4) and [Zn_3.5(μ₃-OH)L₂(BTEC)(H₂O)]·H₂O (5) (L=4-((2-(pyridine-2-yl)-1H-imidazol-1-yl)methyl)benzoic acid, p-H₂BDC=1,4-benzenedicarboxylic acid, m-H₂BDC=1,3-benzenedicarboxylic acid, H₃BTC=1,3,5-benzenetricarboxylic acid, H₄BTEC=1,2,4,5-benzenetetracarboxylic acid), were successfully synthesized under hydrothermal conditions through varying auxiliary aromatic-acid ligands and structurally characterized by X-ray crystallography. Compound 1 exhibits a 1D chain linked via double L bridges. Compound 2 features a well-known pcu topology with bent dicarboxylate ligand (m-H₂BDC) as an auxiliary ligand, while 3 displays a bcu network with linear dicarboxylate ligand (p-H₂BDC) as an auxiliary ligand. The structure of compound 4 is a novel 3D (3,5)-connected network with (4·6²)(4·6⁴·8²·10·12²) topology. It is interesting that compound 5 shows an intricate (3,4,8)-connected framework with (4·6²)(4²·6³·8)(4²·6⁴)(4²·6¹⁸·7·8⁶·10) topology. In addition, their infrared spectra (IR), X-ray powder diffraction (XPRD) and photoluminescent properties were also investigated in detail.     

A Conductometric Study of Complexation Reactions Between Dibenzo-18-Crown-6 (DB18C6) with Cu2+, Zn2+, Tl+ and Cd2+ Metal Cations in Dimethylsulfoxide–Ethylacetate Binary Mixtures

The complex formation between Cu²⁺, Zn²⁺, Tl⁺ and Cd²⁺ metal cations with macrocyclic ligand, dibenzo- 18-crown-6 (DB18C6) was studied in dimethylsulfoxide (DMSO)–ethylacetate (EtOAc) binary systems at different temperatures using conductometric method. In all cases, DB18C6 forms 1:1 complexes with these metal cations. The stability constants of the complexes were obtained from fitting of molar conductivity curves using a computer program, Genplot. The non-linear behaviour which was observed for variations of log K _f of the complexes versus the composition of the mixed solvent was discussed in terms of changing the chemical and physical properties of the constituent solvents when they mix with one another and, therefore, changing the solvation capacities of the metal cations, crown ether molecules and even the resulting complexes with changing the mixed solvent composition. The results show that the selectivity order of DB18C6 for the metal cations in pure ethylacetate and pure dimethylsulfoxide is: Tl⁺ > Cu²⁺ > Zn²⁺ > Cd²⁺ but the selectivity order is changed with the composition of the mixed solvents. The values of enthalpy changes (ΔH°_C) for complexation reactions were obtained from the slope of the van’t Hoff plots and the changes in standard enthalpy (ΔS°_C) were calculated from the relationship: ΔG°_C,298.15=ΔH°_C − 298.15 ΔS°_C. The obtained results show that in most cases, the complexes are enthalpy stabilized, but entropy destabilized and the values of ΔH°_C and ΔS°_C depend strongly on the nature of the medium.     

Syntheses,crystal structures,and magnetic properties of a series of Fe2Ln complexes

A family of phenoxo-bridged heterometallic Schiff base trinuclear complexes, [Fe₂LnL₂(C₃H₇COO)(H₂O)]·CH₃OH·CH₃CN·H₂O (Ln = Sm, 1; Gd, 2; Tb, 3; Dy, 4) is reported. Those complexes were afforded by “one-pot” reaction of a polydentate Schiff base ligand 2-hydroxy-3-methoxy-phenylsalicylaldimine (H₂L) with Fe(NO₃)₃·9H₂O, Ln(NO₃)₃·6H₂O and sodium butyrate (C₃H₇COONa) in a mixture of methanol and acetonitrile in the presence of triethylamine as a base. Single-crystal X-ray diffraction analysis reveals that the structures of the four complexes are isomorphic. In each complex, two anionic [FeL₂]^? units coordinate to the central lanthanide ion as a tetradentate ligand using its four phenoxo oxygens, forming a two-blade propeller-like molecular shape. Magnetic properties of 1–4 were investigated using variable temperature magnetic susceptibility, and weak ferromagnetic exchange between the Fe^III and Ln^III ions has been established for the Gd derivative. The Tb and Dy complexes show no evidence of slow relaxation behavior above 2.0 K.     

Interaction of cysteine with Cu2+ and group IIb (Zn2+, Cd2+, Hg2+) metal cations: a theoretical study

The structure and energetics of complexes obtained upon interaction between cysteine and Zn2+, Cd2+, Hg2+ and Cu2+ cations were studied using quantum chemical density functional theory calculations with the 6-311++G** orbital basis set and relativistic pseudopotentials for the cations. Different coordination sites for metal ions on several cysteine conformers were considered. In their lowest energy complexes with the amino acid, the Zn2+ and Cd2+ cations appear to be three-coordinated to carbonyl oxygen, nitrogen and sulfur atoms, whereas the Cu2+ and Hg2+ ions are coordinated to both the carbonyl oxygen and sulfur atoms of one of the zwitterion forms of the amino acid. Bonds of metal cations with the coordination sites are mainly ionic except those established with sulfur, which show a small covalent character that become most significant when Cu2+ and Hg2+ are involved. The order of metal ion affinity proposed is Cu>Zn>Hg>Cd.     

Syntheses,crystal structures and luminescent properties of two new Zn(II) coordination polymers based on a dicarboxylate and different imidazole-containing ligands

To investigate the effect of different imidazole-containing ligands on the structure of coordination polymers, two new Zn(II) coordination polymers based on 1,4-cyclohexanedicarboxylic acid (H₂cda) and two different imidazole-containing ligands, [Zn(cda)(bib)_0.5]_n (1) and [Zn(cda)(bmib)_0.5]_n (2) (bib = 1,4-bis(imidazol-1-yl)benzene and bmib = 1,4-bis(2-methylimidazol-3-ium-yl)benzene), have been synthesized and characterized by single-crystal X-ray diffraction. Complex 1 shows a 3-D structure with point symbol (4.8².10³).(4.8²). Complex 2 displays a 2-D layer structure with an –AB– stacking sequence.     

基于8-羟基喹啉与d10金属原位合成的双核配合物的合成、晶体结构及其光致发光性质

利用8-羟基喹啉原位反应,通过溶剂热方法制备出3种新颖的d~(10)配合物[M_2(HL)_3]NO_3·H_2O (M=Cd (1),Zn (2,3)),H_2L为1,1-(7,7′-二-(8-羟基喹啉))。单晶结构表明,3种配合物有着相同的带正电荷的结构单元[M_2(HL)_3]~+,但由于客体分子所处空间位置的不同表现为不同的空间结构,配合物1和3结晶于六方晶系(P6_3/m),配合物2结晶于三方晶系(R3)。中心金属离子以六配位的模式与来自HL-配体上的3个氧原子和3个氮原子形成一个轻微扭曲的八面体几何构型。存在于HL-配体与客体分子(NO_3~-,H_2O)间大量的弱作用力在结构空间堆积上起到了重要的作用。3种配合物均具有良好的热稳定性和绿色荧光发射性质。同时,通过从配合物1中提取出原位生成的配体H_2L,首次报道了其蓝色荧光发射性质。     

Revisiting the geometry of nd10 (n+1)s0 [M(H2O)]p+ complexes using four-component relativistic DFT calculations and scalar relativistic correlated CSOV energy decompositions (M(p+) = Cu+, Zn2+, Ag+, Cd2+, Au+, Hg2+)

Hartree-Fock and DFT (B3LYP) nonrelativistic (scalar relativistic pseudopotentials for the metallic cation) and relativistic (molecular four-component approach coupled to an all-electron basis set) calculations are performed on a series of six nd10 (n+1)s0 [M(H2O)]p+ complexes to investigate their geometry, either planar C2v or nonplanar C(s). These complexes are, formally, entities originating from the complexation of a water molecule to a metallic cation: in the present study, no internal reorganization has been found, which ensures that the complexes can be regarded as a water molecule interacting with a metallic cation. For [Au(H2O)]+ and [Hg(H2O)]2+, it is observed that both electronic correlation and relativistic effects are required to recover the C(s) structures predicted by the four-component relativistic all-electron DFT calculations. However, including the zero-point energy corrections makes these shallow C(s) minima vanish and the systems become floppy. In all other systems, namely [Cu(H2O)]+, [Zn(H2O)]2+, [Ag(H2O)]+, and [Cd(H2O)]2+, all calculations predict a C2v geometry arising from especially flat potential energy surfaces related to the out-of-plane wagging vibration mode. In all cases, our computations point to the quasi-perfect transferability of the atomic pseudopotentials considered toward the molecular species investigated. A rationalization of the shape of the wagging potential energy surfaces (i.e., single well vs. double well) is proposed based on the Constrained Space Orbital Variation decompositions of the complexation energies. Any way of stabilizing the lowest unoccupied orbital of the metallic cation is expected to favor charge-transfer (from the highest occupied orbital(s) of the water ligand), covalence, and, consequently, C(s) structures. The CSOV complexation energy decompositions unambiguously reveal that such stabilizations are achieved by means of relativistic effects for [Au(H2O)]+, and, to a lesser extent, for [Hg(H2O)]2+. Such analyses allow to numerically quantify the rule of thumb known for Au+ which, once again, appears as a better archetype of a relativistic cation than Hg2+. This observation is reinforced due to the especially high contribution of the nonadditive correlation/relativity terms to the total complexation energy of [Au(H2O)]+.     

Synthesis,structure and thermal properties of polynuclear complexes with a new multidentate ligand, N,N′-bis(5-ethyl-1,3,4-thiadiazol-2-yl)-2,6-pyridinedicarboxamide

Based on N,N′-bis(5-ethyl-1,3,4-thiadiazol-2-yl)-2,6-pyridinedicarboxamide (H₂L) and inorganic Zn^II and Cd^II salts, three polynuclear complexes [Zn₆(μ₄-O)₂(L)₄] (1), [Zn₃(μ₃-O)₂(L)₂(H₂L)] (2) and [Cd₅(μ₃-O)₂(L)₃(H₂L)(CH₃OH)(DMF)] (3) have been prepared and their crystal structures have been determined by single-crystal X-ray analysis. The thermal behaviors of these complexes in nitrogen and the thermal decomposition kinetics of complex 2 in the temperature range 350–540 °C have been studied, and kinetic parameters were also obtained. Kinetic results show that the decomposition of complex 2 is double-step reaction: a 1st-order reaction (F1) is followed by an nth-order reaction (Fn).     

Syntheses,crystal structures,and some spectroscopic properties of zinc(II) complexes with N2O2 ligands derived from m-phenylenediamine and m-aminobenzylamine

The reaction of bis(salicylidene)-m-phenylenediamine with zinc(II) ion affords a 2?:?2 dinuclear zinc(II) complex formulated as [Zn₂(L¹)₂]. A similar 2?:?2 dinuclear zinc(II) complex, [Zn₂(L²)₂], can be obtained by reaction of bis(salicylidene)-m-aminobenzylamine with zinc(II) ion. These two dinuclear complexes slightly differ in their crystal structures, especially coordination environments around the zinc(II) centers, depending on the dissimilar flexibilities of the two ligands. The differences between the two complexes are reflected in their diffuse reflectance and photoluminescence behaviors.