N-heterocyclic dithiocarbamate platinum(II) complexes: Unexpected transformation of dithiocarbamate to oxodithiocarbonate in phosphinoplatinum complexes in solution

[PtCl₂(dppe)] (dppe = 1,2-bis(diphenylphosphino)ethane) reacts with pyrazol-1-yl- (L1), 3,5-dimethylpyrazol-1-yl- (L2), and indazol-1-yl- (L3) dithiocarbamate to form [Pt(L1)₂(dppe)] (1), [Pt(L2)₂(dppe)] (2) and [Pt(L3)₂(dppe)] (3). These complexes readily transform into [Pt(S₂CO)(dppe)] (4) in chloroform and dichloromethane at room temperature. Stability of the bis(dithiocarbamate)platinum complex from L2, [Pt(L2)₂] (5) suggests that the transformation of 1–3 to 4 is facilitated by the phosphine ancillary ligand.     

Synthesis and structural characterization of [(μ-H)Ru3(CO)8{μ-S(CH2)3SH}(μ-dppe)] and [Ru3(CO)5{μ2-S(CH2)3S}2(η2-dppe)] (dppe=Ph2PCH2CH2PPh2)

The reaction of 1,3-propanedithiol with [Ru₃(CO)₁₀(μ-dppe)] (2) at 66°C afforded the thiolate complexes [(μ-H)Ru₃(CO)₈{μ-S(CH₂)₃SH}(μ-dppe)] (6) and [Ru₃(CO)₅{μ₂-S(CH₂)₃S}₂(η²-dppe)] (7) in 25 and 23% yields respectively. Compound 6 is formed by simple oxidative addition of one of the S–H bonds of 1,3-propanedithiol while the structurally unique 7 consists of an open triruthenium cluster with four terminal and one asymmetrically bridged carbonyl groups, two doubly bridged propanedithiolate ligands and a chelating dppe ligand.     

The reaction between Pt- and Pd-cis di-chloro complexes and 4,4′-diethynylbiphenyl: synthesis and characterisation of a ‘zigzag’ metal/poly-yne polymer

The synthesis of poly-yne polymers containing transition metals inserted in the main chain has been attempted by reacting a dialkyne molecule, 4,4′-diethynylbiphenyl (or DEBP), with [PtCl₂(dppe)] and [PdCl₂(dppe)], the platinum- and palladium-cis square-planar di-chlorine complexes containing diphenylphosphine ethane (dppe) as bidentate ligand. The aim of this work was to obtain organometallic polymers ([Pt(dppe)DEBP]_n and [Pd(dppe)DEBP]_n, respectively) having an all-cis ‘zigzag’ structure, by formation of a σ-acetylide bond between the transition metal complexes and the dialkyne molecule. When [PtCl₂(dppe)] was reacted with DEBP, the formation of a chlorine-terminated [Pt(dppe)DEBP]_n oligomer was evidenced; in the reaction involving the Pd(II) complex, on the other hand, [PdCl₂(dppe)] seems to catalyse the polymerisation of DEBP via opening of the triple bond, producing a poly-DEBP polymer containing Pd(II) atoms inserted in the main chain.     

Square helix versus zigzag chain of group 12 metal coordination polymers with 1,2-bis(diphenylphosphino)ethane (dppe)

A novel 1D square-helical coordination polymer [ZnI₂(μ₂-dppe)]_n (1) was synthesized by the reaction of ZnI₂ with 1,2-bis(diphenylphosphino)ethane (dppe), while zigzag chains [MX₂(μ₂-dppe)]_n were obtained by using smaller anions (Cl^? and Br^?) and larger metal ions (Cd²⁺ and Hg²⁺).     

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.     

First hexanuclear manganese(II) μ6-Cl centered carboxylate anion: Synthesis,structure and magnetic properties

Reaction of manganese(II) polymer [Mn₅Cl(OH)(Piv)₈(MeCN)(HPiv)(H₂O)]_n (1, HPiv is pivalic acid) and 2-benzoylpyridine (L) in MeCN produces the ionic complex [Mn₃(Piv)₅L₂(MeCN)]⁺[Mn₆Cl(Piv)₁₂]⁻ · MeCN (3) containing the unusual hexanuclear {Mn₆(μ₆-Cl)} anion. An analogous anion was also observed in the complex [Mn₆Cl(Piv)₁₂]⁻(NEt₄)⁺ · 5MeCN (4) prepared by the reaction of the polymer [Mn(Piv)₂(EtOH)]_n (2) with NEt₄Cl in MeCN. Complexes 3 and 4 were characterized by the X-ray diffraction and magnetic susceptibility.     

Synthesis and structural characterization of two chain complexes of Mn(II) containing 2-aminopyridinium

The 2-aminopyridine ligand has been exploited in preparation of divalent metal complexes of the formulae [H(2-ampy)][MnCl₃(H₂O)] 1 and [H(2-ampy)]₂[Mn₂Cl₆(2-ampy)₂] 2, where 2-ampy is 2-aminopyridine. Their crystal structures have been determined by X-ray crystallography. Both complexes self-assemble through similar hydrogen bonding motifs which involve three N–H⋯Cl interactions between the 2-aminopyridinium cation and the chloride atoms. Each repeating unit of complexes 1 and 2, [MnCl₃(H₂O)]⁻ and [Mn₂Cl₆(2-ampy)]²⁻, respectively, is doubly edge-sharing to form one-dimensional chains which are cross-linked by hydrogen bonding to the [H(2-ampy)]⁺ cations. In complex 2, two different 2-aminopyridine molecules were observed. One bridges the Mn atoms directly, while the other, through hydrogen bonding interaction, bridges Mn atoms via the chloride atoms. The structural role of the 2-aminopyridinium cation on the aggregation of the metal ions is discussed.     

Preparation and characterization of three types of dinuclear iron(III) complexes with H2salbn,N,N′-disalicylidene-1,4-diaminobutane

By the reaction of the tetradentate Schiff base ligand H₂salbn, N,N^′-disalicylidene-1,4-diaminobutane with Fe^IIICl₃·6H₂O in the presence of Et₃N in MeOH a dinuclear iron(III) complex, [Fe^III(salbn)(μ-OMe)]₂ (1), has been obtained, whereas in EtOH, dinuclear complexes, [Fe^III(μ-salbn)]₂(μ-O) (2) and [Fe^III(salbn)]₂(μ-salbn) (3), are obtained. The structure of the complex 1 consists of two Fe(III) centers with one tetradentate salbn ligand (N₂O₂) which are bridged by two methoxo groups to yield a planar Fe₂O₂ core. On the other hand, in the complex 2, each of the two Fe(III) ions has a five-coordinate structure in which both salbn ligands act as a bridging didentate ligand and one oxygen atom bridges two Fe(III) ions to form a μ-oxo structure. The structure of the complex 3, which was obtained by accompanying with complex 2, consists of two six-coordinate Fe(III) centers in which each Fe(III) ion is coordinated by a tetradentate salbn ligand (N₂O₂) and one bridging salbn ligand (NO).     

Self-assembly through hydrogen-bonding and C–Hπ interactions in metal complexes of N-functionalised glycine

The complex [Ni(L1)₂(py)₂]. toluene (L1 is N-phthaloylglycinato and py is pyridine) was prepared from solid state reaction whereas co-crystals having composition 2[Ni(L1)₂(py)₃(H₂O)] · [Ni(L1)₂(py)₂(H₂O)₂] · 2py · 2H₂O was obtained from solution state reaction.     

Three 3D Cu(II) coordination polymers constructed from 1,2,4,5-benzenetetracarboxylate acid and three positional isomeric ligands

Based on 1,2,4,5-benzenetetracarboxylate acid (H₄btc), and mixed with three isomeric dipyridyl ligands, three novel 3D Cu(II) coordination polymers [Cu₂(btc)(4,4′-bpt)]·2H₂O (1) [4,4′-bpt = 1H-3,5-bis(4-pyridyl)-1,2,4-triazole], [Cu(btc)_0.5(3,4′-bpt)]·0.5H₂O (2) [3,4′-bpt = 1H-3-(3-pyridyl)-5-(4-pyridyl)-1,2,4- triazole] and [Cu(btc)_0.5(3,3′-bpt)]·2H₂O (3) [3,3′-bpt = 1H-3,5-bis(3-pyridyl)-1,2,4-triazole] have been synthesized and characterized, respectively. 1 is a 3D pillared double-layer complex containing a novel bilayer unit; 2 is a 3D pillared-layer architecture with (4,4)-sql layer; 3 exhibits a 3D structure containing 3D [Cu(btc)]_∞ motif and 1D [Cu(bpt)]_∞ chain. The topological analysis shows that 1 can be simplified to a (4,6)-connected network with the Schläfli symbol of (4²·6⁴)₂(4⁸·6⁷), 2 a (4,6)-connected network with the symbol of (4⁴·6²)(4⁴·6¹⁰·8), and 3 a four-connected topology with the symbol of (3²·10³·11)₂(3²·10⁴).     

Synthesis and structural characterization of a triosmium carbonyl cluster containing a 9-anthracenecarbonitrile ligand derived from 9-anthraldehyde oxime

Treatment of [Os₃(CO)₁₁(MeCN)] with 1 equivalent of 9-anthraldehyde oxime in refluxing chloroform afforded a new triosmium cluster [Os₃(CO)₁₁(C₁₄H₉CN)] 1 in moderate yield. Dehydration of oxime and the formation of metal-bound nitrile were observed. Crystal structure analysis revealed that cluster 1 consists of a triangular metal skeleton, with the anthracenecarbonitrile ligand terminally bonded to an osmium atom. Molecular orbital calculations were carried out to gain further insight into the electronic structure of 1. Cluster 1 was also obtained in a higher yield by the reaction of [Os₃(CO)₁₁(MeCN)] with 9-anthracenecarbonitrile.     

The structure of the bismuth ethoxide ethanol solvate. A new structural type for octameric alkoxides

The octanuclear complex of bismuth ethoxide ethanol solvate, [Bi(OEt)₃]₈·(7+x)EtOH (1) has been isolated on crystallization from the ethanol solution of the products from the BiCl₃ metathesis with NaOEt. The molecule of 1 is a [Bi₈] cycle with a crown shape (analogous to that of S₈ in the elementary sulfur), and is built up of seven [Bi(μ-OEt)₄(OEt)] tetragonal pyramids and one [Bi(μ-OEt)₄(OEt)(EtOH)] octahedron. The ring is surrounded by EtOH molecules forming hydrogen bonds with the terminal OEt-groups.     

Oxidation of cobalt(II) to cobalt(III) in the presence of phosphorus and sulphur donors via –O–C bond cleavage: synthesis and structure of [CoIII(dppe)(EtOCS2)(COS2)] (dppe=1,2-bis(diphenyl phosphino)ethane)

An ethanolic solution of cobalt(II) reacts with dppe (1,2-bis(diphenyl phosphino)ethane) and etxant (ethyl xanthate) affording an intensely coloured Co^III complex, [Co^III(dppe)(etxant)(COS₂)], by eliminating [EtOC(S)(SEt)] via –O–C bond rupture. The structure of the cobalt(III) complex has been confirmed by X-ray crystallography, NMR and mass spectrometry.     

Structural diversity of chlorido methoxido- and ethoxido-oxidovanadium(V) complexes: Two-dimensional network,dimer, and unusual syn-oriented V=O functionality

The syntheses and structural characterization of methoxido- and ethoxido-vanadium complexes [VOCl₂(OMe)(HOMe)₂] (1), [VOCl(OMe)₂]₂ (2), and [{VOCl(OEt)₂}₂(THF)] (3) are described. The effects of the reactant ratio, starting materials, and reaction media on the formation of the alkoxido oxidovanadium and their molecular structures are reported. Complex 1 was prepared by reaction of VOCl₃ with three equiv of MeOH in pentane. In the solid state, each molecule of 1 is linked with four symmetry related molecules through four O–H···Cl interactions resulting in the formation of a 2D infinite network. Reaction of VOCl₃ with 2 equiv of NaOMe in pentane yields the dimeric complex 2, which features a pair of methoxido bridges in the molecular structure. In THF, reaction of VOCl₃ with 2 equiv of NaOEt results in a very thermolabile [{VOCl(OEt)₂}₂(THF)] (3), which adopts a butterfly conformation in the molecular structure and features an interesting alkoxido oxidovandium with syn-orientated V=O functionality.     

Gallium(III) chloride-benzotriazole chemistry: variation of product as a function of metal-to-ligand reaction ratio; preparation,structure and properties of a tetrahedral adduct and the first example of a GaX3L2 trigonal-bipyramidal complex

The 1:1 and 1:3 reactions of GaCl₃ with benzotriazole (Hbta) in toluencce-diethyl ether afforded the pseudotetrahedral adduct [GaCl₃(Hbta)] (1) and the novel trigonal-bipyramidal species [GaCl₃(Hbta)₂] (2), respectively, crystal structures of which have been determined. Some spectroscopic properties of the prepared complexes are also discussed.     

2D Cationic Metal-Organic Frameworks of Ag+ with Mixed Ligands (Semi-Rigid Dipyridyl, 3-pmpmd, and Diphosphine, dppe)

Abstract  

With the complex 1 or 2 ([Ag(3-pmpmd)]_n·n(X) (X⁻ = BF₄ ⁻, 1; X = PF₆ ⁻, 2) from the semi-rigid 3-pmpmd (N,N′-bis(3-pyridylmethyl)-pyromellitic diimide) ligand and AgBF₄ or AgPF₆ as the precursor, two new coordination polymers [Ag₂(3-pmpmd)₂(dppe)(BF₄)₂]_n·4nDMF (3) and [Ag₂(3-pmpmd)₂(dppe)(PF₆)₂]_n·4nDMF (4) with the 2D cationic MOFs (metal-organic frameworks), have been obtained in the presence of the second dppe (Ph₂P(CH₂)₂PPh₂) ligand. In the 2D layer network, the 3-pmpmd ligands show the Z _T -mode and the Z _C -mode conformations, and the bridged dppe ligands have the same anti conformation. In the meantime, the functions of the two selected ligands, together with the supramolecular interactions from counter ions and solvates molecules within, should play a key role in the construction of the 2D noninterpenetrated network.     

Structural conversion of cubane-type thallium complex to hexagon silver complex by solid-state mechanochemical reaction

Solid-state structural transformation of Tl^I supramolecular polymer comprised from cubane-type thallium complex of [Tl₄(μ₃-4-BN)₄] (1) (4-HBN = 4-hydroxy benzonitrile) to Ag^I coordination polymer with three nuclear units of [Ag₃(μ₃-4-BN)₂(μ₄-4-BN)] (2) has been studied upon mechanochemical reaction of compound 1 with AgNO₃.     

Unexpected formation of dihaloplatinum(II) and platinum(IV) complexes in the reaction of [PtMe2(bu2bpy)] with 1,2-dibromotetrachloroethane: Crystal structure of trans-[PtMe2BrCl(bu2bpy)]

The platinum(II) complex [PtMe₂(bu₂bpy)] (bu₂bpy = 4,4′-di-tert-butyl-2,2′-bipyridine) (1) reacted with 1,2-dibromotetrachloroethane in a 2:1 mole ratio of Pt(II): (CBrCl₂)₂ to afford trans-[PtMe₂BrCl(bu₂bpy)] (2) and [PtCl₂(bu₂bpy)] (3). The ¹H NMR spectroscopy shows that the Pt–Me bond cleavage is mainly involved after a fast oxidative addition reaction. Complex trans-[PtMe₂BrCl(bu₂bpy)] (2) has been characterized by X-ray diffraction which shows that platinum adopts an octahedral geometry.     

{[Cu(phen)]3Cl4}2[GeMo12O40]: Synthesis,crystal structure and magnetic property of a new trinuclear copper complex based on germanomolybdate

A new trinuclear copper complex based on germanomolybdate, {[Cu(phen)]₃(μ₂-Cl)₄}₂[GeMo₁₂O₄₀] (1) (phen = 1,10-phenanthroline), has been hydrothermally synthesized and structurally characterized by elemental analysis, IR spectroscopy, TG analysis, X-ray powder diffraction (XRPD) and single-crystal X-ray diffraction. Single crystal X-ray analysis reveals that the structural unit of 1 consists of two coordination cations {[Cu(phen)]₃(μ₂-Cl)₄}²⁺ (1a) and a saturated Keggin-type germanomolybdate polyoxoanion [GeMo₁₂O₄₀]^4?. In 1, the most intriguing feature is that each trinuclear copper cation {[Cu(phen)]₃(μ₂-Cl)₄}²⁺ is constructed from three [Cu(phen)]²⁺ cations bridged by four μ₂-Cl atoms. Magnetic measurements indicate 1 shows the ferromagnetic exchange interactions within Cu^II centers.     

Synthesis,structure and properties of the mixed-ligand tungsten(II) complex [WBr2(CO)3(tmpymt)] (tmpymt = 1,4,6-trimethylpyrimidine-2-thione)

The reaction of [{WBr(CO)₄}₂(μ-Br)₂]₂ 1 with 1,4,6-trimethylpyrimidine-2-thione (tmpymt) affords the air-sensitive complex [WBr₂(CO)₃(tmpymt)] 2. The X-ray structure of 2·C₃H₆O reveals that the geometry surrounding the tungsten(II) atom is best described as a distorted capped trigonal prism with a bromine atom Br(1) in the unique capping position. The other bromine atom Br(2), the (N,S)-chelate and one carbonyl C(41) occupy the capped quadrilateral face. The complex has been additionally characterized by IR and NMR spectroscopy. The optimized molecular structure (RHF/LanL2DZ) supports the experimental data.