Synthesis and structure of a high-nuclearity oxomolybdenum(V) complex, [Mo12O28(OC2H5)4(C6H7N)8]

(PyH)[MoOBr₄(H₂O)]·2/3PyHBr (PyH⁺=pyridinium cation, C₅H₅NH⁺) yielded upon the solvothermal reaction with ethanol and 4-methylpyridine (4-MePy, C₆H₇N) a novel oxoethoxomolybdenum(V) cluster, [Mo₁₂O₂₈(OC₂H₅)₄(4-MePy)₈] 1. Molybdenum atoms are grouped into six Mo^V₂ pairs linked by single metal–metal bonds. Three crystallographically independent Mo–Mo distances are 2.5578(14), 2.5981(14) and 2.6489(16) Å.     

Synthesis,crystal structure,and optical property of a one-dimensional selenidostannate: [AEPPH2]2[Sn5Se12] (AEPP = N-aminoethylpiperazine)

A one-dimensional (1-D) selenidostannate, [AEPPH₂]₂[Sn₅Se₁₂] (AEPP = N-aminoethylpiperazine) (1), has been prepared under solvothermal condition and characterized. Single crystal X-ray analysis reveals that compound 1 crystallizes in the triclinic space group P-1, a = 10.6351(7) Å, b = 10.6850(7) Å, c = 10.7771(7) Å, α = 61.3440(10)°, β = 62.4420(10)°, γ = 67.4680(10). With distinct linkage modes between SnSe₄ tetrahedrons and SnSe₆ octahedrons, a secondary building unit (SBU) [Sn₅Se₁₄] is formed. Compound 1 contains infinite bead-like chains built up by the [Sn₅Se₁₄] SBUs, and the protonated [AEPPH₂]^2 + cations are located between the chain spaces. A pseudo 3-D network is formed through C–H···Se and N–H···Se hydrogen bonds between adjacent chains. Its optical property and theoretical band structure and density of state (DOS) calculations have also been studied.     

3D supramolecular open-framework constructed by inorganic [B5O6(OH)4]− and organic [CH3COO]− anions

A borate compound [Ni(en)₃][B₅O₆(OH)₄][CH₃COO] (1) has been synthesized under mild hydrothermal conditions. The newly synthesized compound was characterized by single-crystal X-ray diffraction, elemental analysis and thermogravimetry. The three-dimensional (3D) supramolecular open-framework of compound 1 is constructed by inorganic [B₅O₆(OH)₄]⁻ building units and organic [CH₃COO]⁻ anions through hydrogen bonds, and the charge-balancing [Ni(en)₃]^2 + cations are located in 3D channels. It is very interesting that there exist two helical chains formed by [B₅O₆(OH)₄]⁻ building units and organic [CH₃COO]⁻ anions through hydrogen bonds in compound 1 along different axes. Magnetic measurement indicates that compound 1 exhibits paramagnetic behavior down to 4 K.     

Cost efficient synthesis of bismuth aminoalkoxides from bismuth oxide: Molecular structure of [Bi2(mdea)2(mdeaH)2](mdeaH2)2

Functional Bi alkoxides were prepared by reaction between the oxide and diols such as N-methyldiethanolamine (mdeaH₂), diethanolamine (deaH₂) and triethanolamine (teaH₃) in refluxing toluene in high yields. Similar reactions with polyols without N-donor site lead to oxo species. The derivative obtained with N-methyldiethanolamine was characterised by X-ray diffraction as a dimer [Bi₂(mdea)₂(mdeaH)₂] associated as chains through H-bonding with neutral diol molecules giving the title compound. Bismuth is pseudo 7-coordinate. Bi–O bond distances range from 2.150(5) to 3.093(5) Å with three short ones, whereas the transannular Bi–N bond distances are 2.737 Å av. Thermolysis and hydrolysis reactions are reported.     

Synthesis and crystal structures of two new inorganic–organic hybrid polyoxomolybdate complexes: [Himi]4[{Co(imi)2(H2O)2}Mo7O24] · 4H2O and [Zn(imi)4]2[(imi)2Mo8O26] · 6H2O

The two new inorganic–organic hybrid polyoxomolybdate complexes [Himi]₄[{Co(imi)₂(H₂O)₂}Mo₇O₂₄] · 4H₂O (1) and [Zn(imi)₄]₂[(imi)₂Mo₈O₂₆] · 6H₂O (2) (imi = imidazole) have been prepared by conventional aqueous solution synthesis. Compound 1 consists of heptamolybdate anions [Mo₇O₂₄]⁶⁻ covalently linked by [CoN₂O₄]²⁺ octahedra into one-dimensional zigzag-shaped chains. The zigzag-shaped chains are further linked together via the hydrogen-bonding interactions to form a 2D supramolecular framework. Compound 2 is build up of an imidazole-coordinated octamolybdate anion, two imidazole coordinating zinc cations and lattice water molecules to form a three-dimensional framework via complex hydrogen-bonding.     

A tungstoantimonate coordinated by dmso groups, [Sb2W20(OH)2(dmso)2O66]8−

A novel dmso-coordinated heteropolytungstate [Sb₂W₂₀(OH)₂(dmso)₂O₆₆]⁸⁻ (1) has been successfully isolated as [Ru(bpy)₃]²⁺ salts by routine synthetic reaction in mixed solutions with dmso and water. The compound was characterized by spectroscopic methods as well as by X-ray single crystal structure analysis. The compound represents a tungstoantimonate framework with two W–O–S(CH₃)₂ bonds.     

The spin gap system by self-assembly of benzyl-4-ethylpyridinium and bis(maleonitriledithiolate)niclelate(III) anion

The self-assembly of [BzEtPy]⁺([BzEtPy]⁺ = benzyl-4-ethylpyridinium) cation and the [Ni(mnt)₂]^? (mnt^2? = maleonitriledithiolate) anion results in the forming of a new molecular solid [BzEtPy][Ni(mnt)₂](1), in which the anions and cations stack into columns and the Ni(III) ions form a 1D zigzag alternating chain through Ni···S and π···π interactions between [Ni(mnt)₂]^? anions with the Ni···Ni distances of 3.886 Å and 4.781 Å, and the four columns of cations create cubic-like large channel in which the [Ni(mnt)₂]^? columns are located. Magnetic susceptibility measurements show that 1 exhibits a spin gap transition around 90 K.     

A three-dimensional silver(I) coordination polymer involving a new bridging mode of saccharinate

A three-dimensional silver(I)-saccharinato (sac) coordination polymer [Ag₂(μ-sac)₂]_n has been synthesized and characterized by elemental analysis, IR and single crystal X-ray diffraction. The silver(I) ions are doubly bridged by the imino N and carbonyl O atoms of two sac ligands, leading to a dimer [Ag₂(μ-sac)₂] with a very short Ag–Ag contact of 2.8622(6) Å. The dimeric units are linked by unique Ag–C_sac (η¹) bonds into two-dimensional ladder-like layers, which are further assembled into a three-dimensional network by weak Ag?O(sulphonyl) and π(sac)?π(sac) interactions. Complex 1 is the first example of a polymeric network involving the η¹ Ag–C bonds. In addition to the new coordination mode of sac, the IR spectrum and thermal properties of the complex were discussed.     

Spontaneous magnetization in [1-(4-cyanobenzyl)pyridinium][Pt(mnt)2]: synthesis,crystal structure and magnetic property

A new complex [1-(4-cyanobenzyl)pyridinium][Pt(mnt)₂] (1), in which mnt²⁻ = maleonitriledithiolate, has been prepared and characterized. In the solid state, anions and cations of 1 form completely segregated stacking column, and the [Pt(mnt)₂]⁻ anion column behaves as one-dimensional (1-D) spaced magnetic chains. 1 spontaneously magnetizes at low temperature, which may arises from spin canting.     

Two octamolybdate-based hybrids functionalized by 1,3-bis[tris(hydroxymethyl)methylamino]propane ligand

Two octamolybdate-based organic–inorganic hybrids functionalized by 1,3-bis[tris(hydroxymethyl)methylamino]propane (H₆bthmap) Na₂H₄[γ-Mo₈O₂₆(H₅bthmap)₂]·2H₂O (1) and [NH₄]₆{[Cu(H₃bthmap)]₂(β-Mo₈O₂₆)} (2) have been synthesized through the aqueous synthetic method and structurally characterized by elemental analyses, IR spectra, UV spectra, thermogravimetric (TG) analysis and single-crystal X-ray diffraction. X-ray crystallography reveals that 1 consists of a classic [γ-Mo₈O₂₆]^4 − polyoxoanion decorated by two flexible [H₅bthmap]⁻ ligands through two O atoms from two [H₅bthmap]⁻ ligands and 2 contains a [β-Mo₈O₂₆]^4 − polyoxoanion with bisupporting [Cu(H₃bthmap)]⁻ anions via two terminal O atoms from the [β-Mo₈O₂₆]^4 − polyoxoanion. As far as we know, 1 and 2 represent the first octamolybdate-based hybrids with 1,3-bis[tris(hydroxymethyl)methylamino]propane ligands. The TG curves of 1 and 2 indicate two steps of weight loss and three steps of weight between 25 and 980 °C, respectively. Furthermore, the electrochemical and electrocatalytic properties of 1 and 2 have been investigated.     

Synthesis and crystal structure of a new oxohalide CdPb<Subscript>2</Subscript>O<Subscript>2</Subscript>Cl<Subscript>2</Subscript>

A new compound, CdPb₂O₂Cl₂, is synthesized by the method of solid-phase reactions. The compound has monoclinic symmetry, space group C2/m, a = 12.392(8) Å, b = 3.8040(14) Å, c = 7.658(5) Å, β = 122.64(5)°, and V = 304.0(3) ų. The structure contains one symmetrically independent position of the Pb²⁺ cation coordinated by three O^2? anions (Pb²⁺-O^2? = 2.29–2.34 Å) and five Cl^? anions (Pb²⁺-Cl^? = 3.35–3.57 Å). The Cd²⁺ cation has a symmetric coordination with the formation of two bonds Cd-O = 2.15 Å and four bonds Cd-Cl = 2.73 Å. The oxygen atom is tetrahedrally coordinated by three Pb²⁺ cations and one Cd²⁺ cation, which leads to the formation of oxo-centered heterometallic OPb₃Cd tetrahedra. The tetrahedra are linked together into chains through common Pb atoms and into layered complexes due to sharing of the equatorial Cd atoms. The chlorine atoms are located above the cavities of the oxo-centered layer.     

Nickel(II) thiolates derived from transmetallation reaction of [Zn(Tab)4](PF6)2 with Ni(II) ions and their catalytic activity toward the CN coupling reactions

Reactions of NiCl₂·6H₂O or Ni(ClO₄)₂·6H₂O with 2,2′-bipyridine (2,2′-bipy), or 2-bis(diphenylphosphino)ethane (dppe) or 1,4-bis(diphenylphosphino)butane (dppb) followed by addition of [Zn(Tab)₄](PF₆)₂ (1) resulted in the formation of one trinuclear cationic complex [(2,2′-bipy)₄Ni₃(μ-Tab)₄]Cl_0.5(PF₆)_5.5 (2), one mononuclear cationic complex [Ni(Tab)₂(dppe)](PF₆)₂ (3), and one dinuclear cationic complex [Ni₂(dppb)(μ-Tab)₂(Tab)₂](PF₆)₂(ClO₄)₂ (4). Complexes 2–4 were characterized by elemental analysis, IR, UV–vis, ¹H and ³¹P NMR, and single-crystal X-ray diffraction. In the [(2,2′-bipy)₄Ni₃(μ-Tab)₄]^6 + hexacation of 2, the central Ni(II) atom is connected to two [Ni(2,2′-bipy)₂]^2 + fragments by two pairs of μ-Tab ligands, forming a linear trinuclear cationic structure. The Ni(II) center of the dication of 3 is tetrahedrally coordinated by two S atoms from two Tab ligands and two P atoms of one dppe ligand. Complex 4 has a dimeric cationic structure in which two [(Tab)Ni]^2 + species are linked by a pair of μ-Tab ligands and one dppb ligand. Complexes 2–4 displayed high catalytic activity toward the cross-coupling reactions of arylboronic acids and amines to produce N-arylated amines.     

Preparation, structure and electrochemistry of a polypyrrole hybrid film with [Pd(dmit)2], bis(1,3-dithiole-2-thione-4,5-dithiolate)palladate(II)

The synthesis of a hybrid material obtained by electropolymerization of a solution of pyrrole and [NEt₄]₂[Pd(dmit)₂] (1,3-dithiole-2-thione-4,5-dithiolate, [dmit]²⁻, [C₃S₅]²⁻) in acetonitrile solution is reported. FTIR and UV-vis spectroscopy showed that the [Pd(dmit)₂]²⁻ anion had been inserted in the polypyrrole framework without modification during the electropolymerization process. Cyclic voltammetry showed that the material has electroactivity undergoing redox processes related to the conducting polymer and the counteranion. The electrochemical results also suggest that the counteranion is not trapped in the PPy matrix undergoing anion exchange during the redox cycle of PPy. The PPy/[Pd(dmit)₂]²⁻ exhibits good thermal stability and has a higher intrinsic conductivity value (4.27 × 10⁻³ S cm⁻¹) than do other PPy/dmit films previously studied.     

Dendrimer-like cyanoruthenate anions with high potential connectivity derived from a [Ru(bpym)3]2+ core

Reaction of [Ru(bpym)₃]²⁺ (bpym = 2,2′-bipyridmidine) with hexacyanoruthenate under forcing conditions affords a mixture of the trinuclear species [(bpym)Ru{(µ-bpym)Ru(CN)₄}₂]^2?, [1]^2?, and the tetranuclear species [Ru{(µ-bpym)Ru(CN)₄}₃]^4?, [2]^4?, in which two or three (respectively) of the peripheral vacant bpym binding sites of [Ru(bpym)₃]²⁺ are occupied by {Ru(CN)₄}^2? fragments. Thus, [1]^2? and [2]^4? have eight and twelve externally-directed cyanide groups respectively for use in forming high connectivity coordination networks. The crystal structure of HK[1]·2MeOH·6.5H₂O reveals a one-dimensional ladder structure in which [1]^2? anions are connected by (i) cyanide/K⁺ and (ii) bpym/K⁺ coordination interactions.     

The first example of half-sandwich cobalt(III) complex with hydrotris(pyrazolyl)borate ligand

This paper presents the synthesis, crystal structure and spectroscopic properties of a novel half-sandwich mononuclear cobalt(III) complex with hydrotris(3,5-dimethylpyrazolyl)borate ligand and thiocyanate [Tp^*Co(Hpz^*)(NCS)₂]·H₂O·CH₃OH (Tp^*: hydrotris(3,5-dimethyl- pyrazolyl)borate, Hpz^*: 3,5-dimethylpyrazole). The structure was determined by X-ray diffraction. The complex crystallizes in the monoclinic system, space group C_c, a=18.591(6) Å, b=10.536(3) Å, c=17.568(5) Å, β=11.284(5)°, Z=4, R₁=0.0501, wR₂=0.1179. The cobalt(III) ion in the complex is six-coordinated with nitrogen atoms, three from Tp^*, two from pyrazole and two from two thiocyanates, to form octahedral environment. The hydrogen atoms of O(2) of water molecule are connected by hydrogen bonds with S atoms of two adjacent complex molecules to form 1-D chains. The hydrogen atom of N(8) of complex molecule is connected by hydrogen bond with methanol. The spectroscopic results are consistent with the crystallographic study.     

Syntheses and structures of eight-semi-coordinate M(II) (M = Mn,Fe, Co,Ni, Cu,Zn) complexes and density functional theory study of bond dissociation energies for the MO semi coordinate bonds

Six new complexes 1–6 with the common formula [M(NiL)₄][M(NCS)₄] (M = Mn, Fe, Co, Ni, Cu and Zn for 1, 2, 3, 4, 5 and 6, respectively; the same below) were synthesised and structurally characterised by X-ray single crystal analysis. NiL acts as a complex ligand. L denotes the dianion of dimethyl 5,6,7,8,15,16-hexahydro-6,7-dioxodibenzo-[1,4,8,11]tetraazacyclotetradecine-13,18-dicarboxylate. Each M(II) centre of the [M(NiL)₄]^2 + complex cations in 1–6 adopts a distorted square-antiprism coordination geometry with a O₈ donor set. All the MO bonds in the six complexes are abnormally long (2.444–2.528 Å). M(II) complexes having such weak coordination environments have not been reported, and eight-coordinate M(II) complexes with all the eight oxygen donor atoms coming from metalloligands have also not been documented. Each M(II) centre of the [M(NCS)₄]^2 − anions in 1–6 has a distorted tetrahedral coordination environment with a N₄ donor set. Theoretical calculations for the bond dissociation energies (BDEs) of the MO semi coordinate bonds were performed using density functional theory at B3LYP level. The calculated BDE values are 23.8, 25.5, 20.0, 22.3, 19.8 and 18.2 kcal/mol for 1, 2, 3, 4, 5 and 6, respectively. The BDE values suggest that the long MnO bonds in 1 and the long CoO bonds in 3 are significantly weaker than their significantly shorter counterparts in the formerly reported [Mn(NiL)₂(NCS)₂] and [Co(NiL)₂(NCS)₂], respectively.     

Hydrothermal Syntheses and Crystal Structures of Three Zn(II) Coordination Compounds Constructed with 3,5-Pyrazoledicarboxylic Acid

Three novel metal–organic coordination compounds, [Zn(Hdcp)(H₂O)₄]·1.5H₂O (1), [Zn(Hdcp)(H₂O)₂]_∞ (2) and [Zn₃(dcp)₂(H₂O)₅]_∞ (3) with the ligand 3,5-pyrazoledicarboxylic acid were prepared by the hydrothermal method. The complexes were structurally characterized by elemental analysis, IR spectroscopy and X-ray single-crystal diffraction. Compound 1 is a mononuclear molecule that is linked into a 3D supramolecular framework via N–H···O and O–H···O hydrogen bonds. In 2, two types of carboxylic bridges were found between Zn^II ions to form a 1D double-chain. The 1D chains were further construct into a 3D structure by hydrogen bonds. Trinuclear 3 consists of 1D bi-infinite parallelogram chains of [Zn₃(dcp)₂(H₂O)₃] trimers. In the basic trinuclear unit a further bridging mode of the ligand is seen where two dcp^3? ligands chelate three Zn^II ions by utilizing five donors of the dcp^3? ligand. The photoluminescent properties of 1, 2 and 3 were investigated.     

Synthesis,Characterization, Crystal Structures and Thermal and Fluorescence Studies of Dinuclear and Polymeric Silver(I) Complexes of 5,5-Diethylbarbiturate with 2,5-Dimethylpyrazine and Piperazine Involving Ag–Ag Interactions

Two silver(I) complexes, [Ag(dmpyz)₂][Ag(barb)₂] (1) and {[Ag(ppz)][Ag(barb)₂]·H₂O} _n (2) (barb = 5,5-diethylbarbiturate, dmpyz = 2,5-dimethylpyrazine and ppz = piperazine), have been synthesized and characterized by elemental analyses, IR, thermal analysis (TG-DTA) and single-crystal X-ray diffraction. Complex 1 consists of [Ag(dmpyz)₂]⁺ and [Ag(barb)₂]^? ions in which the silver(I) ions are linearly coordinated by two dmpyz or two barb ligands. These two ions are connected by strong Ag–Ag interactions (Ag–Ag = 2.896 (1) Å). Complex 2 is a 1D coordination polymer in which the silver(I) ions are bridged by the ppz ligands in a linear fashion, leading to a zigzag chain of [Ag(ppz)] _n ⁺ , which interacts with the [Ag(barb)₂]^? units by Ag–Ag interactions of 3.183 (1) Å. The 1D chains are further assembled to form 3D networks by strong N–H···O and OW–H···O hydrogen bonds. IR spectra and TG-DTA data are in agreement with the crystal structures. The fluorescent properties of 1 were also evaluated.     

A 2D helical coordination polymer based on Keggin-type polyoxoanion: Synthesis,crystal structure and luminescent properties

A novel two-dimensional helical coordination polymer [Ag(CH₃CN)₄][Ag₃(CH₃CN)₈(SiMo₁₂O₄₀)] (1) has been gained by the conventional self-assembly reaction, and characterized by IR, elemental analysis, UV, TG technique and X-ray single crystal diffraction. Each [SiMo₁₂O₄₀]^4? cluster interconnects with three bimetallic cation subunits through three Mo–O–Ag bridges, meanwhile, each bimetallic cation subunit is surrounded by three [SiMo₁₂O₄₀]^4? to form an unprecedented two-dimensional network structure. The metal–metal bonds between Ag(1) and Ag(2) atoms from the adjacent helical chains connects the chains together into a chiral 2D helical network. The 2D network structures are further interconnected with each other to form a 3D supramolecular network through multiform intermolecular hydrogen bonds. The luminescent properties of the coordination polymer in the solid state were investigated.     

Syntheses and Structural Characterization of Co(II) Coordination Polymers Supported by Bis(<Emphasis Type="Italic">N</Emphasis>-benzimidazolyl)methane and Bis(<Emphasis Type="Italic">N</Emphasis>-imidazolyl)methane

[Co₂(L¹)₂(NCS)₄]·4MeOH 1, [Co(L²)₂(H₂O)₂](Sal)₂·4H₂O (Sal = salicylate) 2 were obtained from self-assembly of the cobalt salts with bis(N-benzimidazolyl)methane (L¹), and bis(N-benzimidazolyl)methane (L²), and their structures were characterized by IR and X-ray diffraction analysis. Complex 1 exhibits a two-dimensional grid structure, whereas complex 2 is a coordination polymer having a one-dimensional linear chain structure. The grid in 1 lies parallel to the crystallographic ab plane and exhibits intra-grid M–M separations of 10.508 × 10.508 Å. Hydrogen bonds hold the cationic chains in 2 together leading to a three-dimensional network structure.