Synthesis, spectral and X-ray structural studies of Ni(II) complexes of N′-acylhydrazine carbodithioic acid esters containing ethylenediamine or o-phenanthroline as coligands

The new complexes [Ni(Hbstbh)₂(en)] (1) and [Ni(Hpchce)(o-phen)₂]Cl·CH₃OH·H₂O (2) with N′-benzoyl hydrazine carbodithioic acid benzyl ester (H₂bstbh) and [N′-(pyridine-4-carbonyl)-hydrazine]-carbodithioic acid ethyl ester (H₂pchce) have been synthesized, containing ethylenediamine (en) or o-phenanthroline (o-phen) as coligands. The ligands and their complexes have been characterized by elemental analyses, IR, magnetic susceptibility and single crystal X-ray data. [Ni(Hbstbh)₂(en)] (1) and [Ni(Hpchce)(o-phen)₂]Cl·CH₃OH·H₂O (2) crystallized in the monoclinic and triclinic systems, space group C2/c and P-1, respectively. The (N, O) donor sites of the bidentate ligands chelate the Ni(II) center and form a five-membered CN₂ONi ring. The resulting complexes are paramagnetic and have a distorted octahedral geometry.     

Nickel(II), copper(II), and cobalt(II) complexes derived from a new unsymmetrical ONS donor Schiff base ligand: synthesis,characterization, crystal structure,and catalytic activities

Ni(II), Cu(II), and Co(II) complexes, ML₂, with a new thioether containing ONS donors were synthesized, where L = deprotonated Schiff base. The analytical, spectral (FTIR, ¹H NMR, and UV-vis), conductivity, and magnetic studies show that the metal complexes possess octahedral geometry and are non-electrolytes. The coordination mode of ligand, 1, and nickel(II) complex, NiL₂, 2, was determined by single-crystal X-ray diffraction studies. Here, the nickel is coordinated to two oxygens, two nitrogens, and two sulfurs of two tridentate ligands with slightly distorted octahedral environment around nickel. The copper complex shows very good catalytic activities towards oxidation of organic thioethers to the corresponding sulfoxide predominantly using H₂O₂ as the oxidant.     

Nickel(II) and copper(II) complexes of allyl 2-(thiophen-2-ylmethylene)hydrazinecarbodithioate: synthesis,X-ray crystal structures,and theoretical study

We report allyl 2-(thiophen-2-ylmethylene)hydrazine-carbodithioate (HL) and its Ni(II) and Cu(II) complexes, [ML₂]. The compounds were fully characterized by elemental analysis, IR, ¹H-NMR, UV-Vis, and molar conductivity. The crystal structure analysis indicates that the metal is four-coordinate square planar and that a parallel stacking of the molecular planes is present in the crystals, with stacking distances of 3.642 and 3.676?Å for the Ni(II) and Cu(II) complexes, respectively. Gas phase DFT computations indicate that the thione tautomeric form of the free ligand is more stable than the thiol form by 14.52?kJ?mol^–1. For HL and ML₂, comparison between the computed and experimental data shows good agreement.     

Novel thiocyanate complexes of cadmium(II) - Synthesis, spectroscopic characterization, X-ray studies and DFT calculations

Three novel thiocyanate cadmium(II) compounds [Cd(ind)₂(SCN)₂]_n (1), [Cd(dpa)Cl(SCN)]_n (2) and [Cd(terpy)(SCN)₂] (3) were synthesized and characterized by spectroscopic and crystallographic methods. Thiocyanate ions of 1 act as bridging ligands generating a one-dimensional chain constructed of Cd(SCN)₂Cd units and expanding along the crystallographic direction [1 0 0]. The Cd(II) ions of 2 are bridged by alternating di-μ-Cl and di-μ_1,3-NCS bridges to one-dimensional chain running along the crystallographic direction [0 1 0]. [Cd(terpy)(SCN)₂] (3) is a square pyramidal mononuclear compound.The fluorescence properties of the complexes 1 and 2 were examined in solid state, whereas fluorescence spectra of 3 were recorded in both solid state and solution. All they were compared with the fluorescence properties of the free ligands. Additionally, the electronic spectrum of 3 were investigated at the TDDFT level employing B3LYP functional in combination with LANL2DZ.     

Synthesis,structural and spectroscopic characterization of a new cadmium(II) complex containing imidazole (Im) as ligand, [Cd(Im)6](ClO4)2

Reaction between the 1,1′-carbonyldiimidazole ligand and mixtures of cadmium(II) acetate with sodium perchlorate provided the unusual crystalline material [Cd(Im)₆](ClO₄)_2, (Im?=?imidazole). This new Cd^II complex, has been characterized by elemental analysis, IR-, ¹H NMR-, ¹³C NMR and ¹¹³Cd NMR spectroscopy. The coordination number in this complex is six, CdN₆ and coordination environment around the Cd(II) may be described as distorted octahedral with a D_2h point group. There are both edge-to-face π–π stacking and C–H(Im)?···?π interactions between aromatic “Im” rings belonging to adjacent chains in this network.     

Synthesis and structural characterization of Ni(II) complexes with the chiral CpH(PNMent) tripod ligand

Treatment of NiCl₂ with the tripod ligand (L_Ment,S_C)-1H led to (L_Ment,S_C)-[Cp(PN_Ment)NiCl] in which the potentially tridentate ligand coordinated to the metal center in a bidentate way via the cyclopentadienyl system and the phosphorus atom. In the presence of NH₄PF₆ [(L_Ment,S_C)-[Cp(PN_Ment)NiCl] readily underwent Cl/PPh₃ exchange to give (L_Ment,S_C)-[Cp(PN_Ment)NiPPh₃]PF₆. Reaction of (L_Ment,S_C)-[Cp(PN_Ment)NiCl] with 0.5 eq. of dppe afforded [{(L_Ment,S_C)-[Cp(PN_Ment)Ni]}₂dppe](PF₆)₂. (L_Ment,S_C)-[Cp(PN_Ment)NiPPh₃]PF₆ and [{(L_Ment,S_C)-[Cp(PN_Ment)Ni]}₂dppe](PF₆)₂ were characterized by NMR and MS spectroscopy, and also by single crystal X-ray diffraction. The cyclopentadienyl ligand of (L_Ment,S_C)-[Cp(PN_Ment)NiPPh₃]PF₆ shows a distortion intermediate between the ene-allyl and diene types, while the two cyclopentadienyl ligands of [{(L_Ment,S_C)-[Cp(PN_Ment)Ni]}₂dppe](PF₆)₂ have intermediate and diene distortions, respectively. According to the temperature dependent NMR spectra of (L_Ment,S_C)-[Cp(PN_Ment)NiPPh₃]PF₆ and [{(L_Ment,S_C)-[Cp(PN_Ment)Ni]}₂dppe](PF₆)₂ two different conformations of the tether in the Cp(PN_Ment)Ni system could be frozen out at low temperatures.     

Synthesis, spectroscopic characterization and X-ray studies of two novel double open cubane-like cadmium(II) complexes

Two novel azide cadmium(II) compounds [Cd₄(dafone)₄Cl₂(μ_1,1-N₃)₄(μ_1,1,1-N₃)₂] (1) and [Cd₄(dafone)₄(N₃)₂(μ_1,1-N₃)₄(μ_1,1,1-N₃)₂] (2) were synthesized and characterized by spectroscopic and crystallographic methods. They are first cadmium(II) complexes adopting double open cubane-like structure. The fluorescence properties of the complexes 1 and 2 were examined both in solid state and solution, and compared with the free ligand. Additionally, the electronic spectra of 4,5-diazafluoren-9-one and 1 were investigated at the TDDFT level.     

Synthesis,spectroscopic and X-ray structural studies of mercury(II) halide complexes of 4-methoxybenzoylmethylenetriphenylphosphorane

The reactions of the title ylide {(C₆H₅)₃PCHCOC₆H₄OCH₃)} (MBPPY) with mercury(II) chloride and mercury(II) bromide in equimolar ratios using methanol as the solvent produces crystals of [(MBPPY) · HgCl₂]₂ (1) and [(MBPPY) · HgBr₂]₂ (2), respectively. Single crystal X-ray analyses reveal the presence of centrosymmetric dimeric structures containing the ylide and HgX₂ (X = Cl or Br) in both cases. The IR and NMR data of the product [(MBPPY) · HgI₂]₂ (3), formed by the reaction of mercury(II) iodide with the same ylide, are similar to those of 1 and 2. Analytical data indicate a 1:1 stoichiometry between the ylide and Hg(II) halide in each of the three products.     

Synthesis,structural analysis,and thermal and spectroscopic studies of methylmalonate-containing zinc(II) complexes

The synthesis, crystal structure, thermal analysis and spectroscopic studies of five zinc(II) complexes of formulae [Zn(Memal)(H₂O)]_n (1) and [Zn₂(L)(Memal)₂(H₂O)₂]_n (2-5) [H₂Memal = methylmalonic acid, and L = 4,4′-bipyridine (4,4′-bpy) (2), 1,2-bis(4-pyridyl)ethylene (bpe) (3), 1,2-bis(4-pyridyl)ethane (bpa) (4) and 4,4′-azobispyridine (azpy) (5)] are presented here. The crystal structure of 1 is a three-dimensional arrangement of zinc(II) cations interconnected by methylmalonate groups adopting the μ₃-κ²O:κO’:κO”:κO”’ coordination mode to afford a rare (10,3)-d utp-network. The structures of the compounds 2-5 are also three-dimensional and they consist of corrugated square layers of methylmalonate-bridged zinc(II) ions which are pillared by bis-monodentate 4,4′-bpy (2), bpe (3), bpa (4) and azpy (5) ligands. The Memal ligand in 2-5 adopts the μ₃-κO:κO′:κO′′:κO′′′ coordination mode. Each zinc(II) ion in 1-5 is six-coordinated with five (1)/four (2-5) methylmalonate-oxygen atoms, a water molecule (1-5) and a nitrogen atom from a L ligand (2-5) building distorted octahedral environments. The rod-like L co-ligands in 2-5 appear as useful tools to control the interlayer metal-metal separation, which covers the range 8.4311(5) Å (2) – 9.644(3) Å (5). The influence of the co-ligand on the fluorescence properties of this series of compounds has been analyzed and discussed by steady-state and time resolved spectroscopy on all five compounds in the solid state.     

Topological diversification of two new Cd(II) photoluminescent coordination polymers via auxiliary N-donor ligands

Two new cadmium(II) coordination polymers, [Cd₂(nda)₂(L₁)] _n (1) and [Cd(nda)(L₂)_0.5] _n (2), were hydrothermally synthesized with 1,4-naphthalenedicarboxylic acid (H₂nda) and auxiliary N-donor coligands [L₁?=?1,5-bis(2-methyl-imidazol-1-yl)pentane and L₂?=?4,4′-bis(2-methyl-imidazol-1-ylmethyl)biphenyl]. Single-crystal X-ray diffraction analyses showed that the topological networks are different when the N-donor ligands are changed. Compound 1 showed a (4¹⁶.6⁵) topology and 2 showed a twofold interpenetrating pcu topology.     

Heterobimetallic Mn(II)-Hg(II) polynuclear complexes containing Hg(SCN)4 unit - Synthesis, spectroscopic investigations, X-ray studies and magnetic properties

Two novel heterobimetallic coordination polymers with Hg(SCN)₄²⁻ as a linker have been synthesized and characterised by means of IR, EPR, magnetic measurements and single crystal X-ray. The compounds [Mn(bpzm)Hg(SCN)₄]_n (1) and [Mn(bdmpzm)₂Hg(SCN)₄]_n (2) form supramolecular framework structures. The compound 1 creates a three-dimensional coordination polymer and compound 2 has one-dimensional chain structure extending along the crystallographic direction [1 0 0]. Variable-temperature magnetic susceptibility measurements show very weak antiferromagnetic interactions between the paramagnetic Mn(II) centres of structures 1 and 2.     

High-spin iron(III) complexes: structural,spectroscopic, and photochemical studies

Reaction of FeCl₃ with one equivalent of acac (acac = pentane-2,4-dionate) and KTp^Me2 (Tp^Me2 = hydrotris(3,5-dimethyl-pyrazol-1-yl)borate) yielded Tp^Me2Fe(acac)Cl (3), which upon reaction with methanolic solution of sodium azide resulted in the formation of a six coordinate compound Tp^Me2Fe(acac)N₃ (4) with a single azide. When the reaction of FeCl₃ and KTp^Me2 was performed with two equivalents of sodium azide and one equivalent of 3,5-dimethylpyrazole (Pz^Me2H), a six coordinate cis azide compound [Tp^Me2Fe(Pz^Me2H)(N₃)₂] (5) was obtained. These compounds were characterized by spectroscopic methods and single crystal X-ray crystallography. Electrochemical studies of 5 show that it can be irreversibly reduced at relatively lower potential than 4. The photolysis of 5 was performed at 77 K at different wavelengths (480, 419, and 330 nm) showing that 5 was photoreduced to a high-spin Fe(II) species instead of photooxidized to Fe(V).     

Cu(II), Cd(II) and Ni(II) azide complexes incorporating bis(3,5-dimethylpyrazol-1-yl)methane - Synthesis, spectroscopic characterisation, X-ray studies and magnetic properties

Three novel compounds [Cu₂(μ_1,1-N₃)₂(N₃)₂(bdmpzm)₂] (1) [Cd(N₃)₂(bdmpzm)]_n (2) and [Ni(N₃)₂(bdmpzm)₂] (3) have been synthesised and characterised structurally and spectroscopically. The structure 1 consists of a neutral dinuclear [Cu₂(μ_1,1-N₃)₂(N₃)₂(bdmpzm)₂] entities, compound 2 has one-dimensional zigzag chain structure extending along the crystallographic direction [1 0 0] with alternating di-μ_1,1-N₃ and di-μ_1,3-N₃ bridges, and 3 is a mononuclear complex. The experimental studies on the nickel(II) complex have been accompanied computationally by the density functional theory (DFT) calculations.     

Syntheses and characterization of mixed-anion cadmium(II) complexes,structural characterization of [Cd(phen)2(NO2)1.65(NO3)0.35], as a new eight-coordinate Cd(II) complex

New mixed-anion cadmium(II) complexes of 2,2′-bipyridine (bpy) and 1,10-phenanthroline (phen) ligands, [Cd(phen)₂(NO₂)_1.65(NO₃)_0.35] and Cd(bpy)(ClO₄)(CH₃COO) have been synthesized and characterized by elemental analysis, IR-, ¹H NMR-, ¹³C- NMR and ¹¹³Cd NMR spectroscopy. The single crystal X-ray data of [Cd(phen)₂(NO₂)_1.65(NO₃)_0.35] show the complex to be a monomer and that the Cd atom has an unsymmetrical eight-coordinate geometry, being coordinated by four nitrogen atoms of ‘phen’ ligands and four oxygen atoms of the nitrite and nitrate anions. There is a short π–π stacking interaction between parallel aromatic rings.     

Spectroscopic and structural studies of the 2D Mn(II) coordination polymer from a bridging Noxa, Npy bidentate ligand; tetra-n-butylammonium[5-(3-pyridyl)-1,3,4-oxadiazole-2-thiolate]

A coordination polymer {[Mn(3-pyt)₂(H₂O)₂][N(n-Bu)₄]⁺[3-pyt]⁻}_n (3) has been synthesized from the reaction of tetra-n-butylammonium[5-(3-pyridyl)-1,3,4-oxadiazole-2-thiolate] {[N(n-Bu)₄]⁺[3-pyt]⁻} and Mn(OAc)₂ · 4H₂O. The ligand and the Mn(II) complex 3 have been characterized by elemental analyses, IR, ¹H and ¹³C NMR spectroscopy, in addition 3 has also been studied crystallographically. The single crystal X-ray structure of the 3 shows that the ligand is bonded to Mn(II) via its pyridyl and oxadiazole nitrogen atoms. This bonding pattern connects the Mn(II) centres to afford an uniform two dimensional coordination frame work where the [Mn(3-pyt)₂(H₂O)₂]_n molecules are stacked in a parallel layers. The overall arrangement of molecules in crystal lattice results in open channels in which the enclosed tetra-n-butylammonium cations are stabilized by anionic oxadiazole molecules through N⁺···S⁻ ionic interactions.     

一维链状[Mn(9-AC)2(4,4'-bpy)(H2O)2]n配位聚合物的合成及晶体结构

在水热条件下(120 ℃), 将醋酸锰、4,4'-联吡啶(4,4'-bpy)与9-蒽酸(9-HAC)反应, 得到了配位聚合物[Mn(9-AC)2(4,4'-bpy)(H2O)2]n, 通过元素分析、红外光谱、X射线单晶衍射对其进行了表征, 并用TGA研究了该配位聚合物的热稳定性. 结构解析结果表明, 该晶体属于正交晶系, Fdd2空间群, a=1.66772(12) nm, b=3.36471(16) nm, c=1.1687(4) nm, V=6.558(2) nm3, Z=8, Mr=689.60, Dc=1.397 Mg/m3, R=0.0356, wR2 = 0.0604. 在该配位聚合物中, 中心锰原子采取略微变形的八面体构型, 与两种配体共同构筑了一维直线形链结构, 链与链之间通过氢键相互作用构筑成三维超分子网络.     

Synthesis,spectroscopic and structural characterization of new complex of ruthenium(II) with Hmtpo ligand

The [(PPh₃)₂RuHCl(CO)(Hmtpo)] complex has been prepared and studied by IR, NMR, UV–VIS spectroscopy and X-ray crystallography. The complex was prepared in reactions of [RuHCl(CO)(PPh₃)₃] with 7-hydroxy-5-methyl[1,2,4]triazolo[1,5-a]pyrimidine in methanol. The electronic structure and UV–Vis spectrum of the obtained compound have been calculated using the TD–DFT method.     

Cu(II)/Cd(II) coordination polymers based on polycarboxylate and 2-(2-pyridyl)benzimidazole

Three polycarboxylate coordination polymers containing 2-(2-pyridyl)benzimidazole as co-ligand, [Cu(Bdc)(2-PyBIm)] _n (1), [Cu(HBtc)(2-PyBIm)] _n (2) and [Cd₂(HBtc)₂(2-PyBIm)₂] _n ·; nH₂O (3) (H₂Bdc?=?1,4-benzenedicarboxylic acid; H₃Btc?=?1,3,5-benzenetricarboxylic acid), have been synthesized and characterized by elemental analyses, IR spectra, TG-DSC and X-ray structural analyses. Complex 1 is a one-dimensional zigzag chain in which the Cu(II) is cis six-coordinated by two chelating carboxyl groups and a 2-PyBIm ligand. Complex 2 is a two-dimensional (4, 4) network in which H₃Btc is partially deprotonated. Complex 3 has a three-dimensional framework in which one Cd(II) is six-coordinate and the other is seven-coordinate. All 2-PyBIm groups are neutral, chelating, bidentate ligands in 1–3. These complexes are quite thermally stable. The luminescence of 3 has also been investigated.     

Preparation, crystallography and spectroscopic properties of the polymeric {(1-(E)-2-pyridinylmethylidene)semicarbazone)(aqua)copper(II)} sulphate dihydrate complex: evidence of dynamic Jahn-Teller effect

Pyridine-2-carbaldehyde semicarbazone ligand (HL) reacts with copper(II) sulphate in water solution to yield the coordination polymer [{Cu(II)(HL)(H(2)O)(SO(4))}(n)] (1). The crystals are triclinic with space group P(-1) and the metal ion is occupying a distorted octahedral geometry. EPR results show that a dynamic Jahn-Teller (J-T) effect is operative in water solutions and also support the stability of the polymeric chains as they continue to show a characteristic half-field Δm(S)=±2 transitions. UV-visible spectrum analysis allowed access to the J-T stabilization energy of 5995 cm(-1) in water. Thermogravimetric/differential thermal analysis curves showed a step-by-step decomposition of complex 1 with loss of water, release of SO(3) and oxidation of the semicarbazone ligand in the 30-422°C range.