Synthesis and crystal structure of [W3S4(Acac)3(PPh3)3]PF6 · 0.5CHCl3 and [W3S4(Hfac)3(PPh3)2Br] · 2CHCl3

New cluster complexes [W₃S₄(Acac)₃(PPh₃)₃]PF₆ · 0.5CHCl₃ (Acac = CH₃C(O)CHC(O)CH₃) (I) and [W₃S₄(Hfac)₃(PPh₃)₂Br] · 2CHCl₃ (Hfac = CF₃C(O)CHC(O)CF₃) (II) were synthesized. Their molecular and crystal structures were determined by X-ray diffraction. The cis-cis type of coordination of acetylacetonate and hexafluoroacetylacetonate ligands in I and II, respectively, was established, and the PPh₃ ligands were found in the trans-positions with respect to the “capping” sulfide ligand (μ³-S).     

Heterogeneous single-cluster catalysts(Mn3,Fe3,Co3,and Mo3)supported on nitrogen-doped graphene for robust electrochemical nitrogen reduction

Electrochemical nitrogen reduction reaction(NRR)is one of the most promising alternatives to the traditional Haber-Bosch process.Designing efficient electrocatalysts is still challenging.Inspired by the recent experimental and theoretical advances on single-cluster catalysts(SCCs),we systematically investigated the catalytic performance of various triple-transition-metal-atom clusters anchored on nitrogen-doped graphene for NRR through density functional theory(DFT)calculation.Among them,Mn₃-N4,Fe₃-N4,Co₃-N4,and Mo₃-N4 were screened out as electrocatalysis systems composed of non-noble metal with high activity,selectivity,stability,and feasibility.Particularly,the Co₃-N4 possesses the highest activity with a limiting potential of-0.41 V through the enzymatic mechanism.The outstanding performance of Co₃-N4 can be attributed to the unique electronic structure leading to strong π backdonation,which is crucial in effective N₂ activation.This work not only predicts four efficient non-noble metal electrocatalysts for NRR,but also suggest the SCCs can serve as potential candidates for other important electrochemical reactions.     

Novel chromium trinuclear trifluoroacetate complexes Cr3(μ3-O)(CF3COO)6(CH3COOH)2(CF3COO) and Cr3(μ3-O)(CF3COO)6(CH3COOH)2(THF): Synthesis and crystal structure

Novel anhydrous trinuclear ₃-oxo complexes of Cr(III), Cr₃(₃-O)(CF₃COO)₆(CH₃COOH)₂(CF₃COO) (I) and of Cr(III,III,II), Cr₃(₃-O)(CF₃COO)₆(CH₃COOH)₂(THF) (II) (where THF is (CH₂)₄O) are synthesized by anodic dissolution of metallic chromium in solutions of trifluoroacetic acid in acetonitrile and in tetrahydrofuran and their structures are studied by X-ray diffraction analysis. Complex I forms orthorhombic crystals with space group Pna2₁, a = 9.778(1) , b = 16.042(2) , c = 22.851(4) , Z = 4, R ₁ = 0.0332; complex II crystallizes in monoclinic system: space group P2₁/c, a = 9.866(1) , b = 17.895(2) , c = 21.167(4) , = 100.75(2)°, Z = 4, R = 0.0422. The average Cr-(₃-O) distances in compounds I and II are almost equal (1.943(3) and 1.927(3) ). An average length of the Cr-O bond in octahedral surrounding of metal atoms is different in complexes I and II (1.985(4) and 2.003(3) , respectively), which is specified by different oxidation states of the metal atom. The CrCr distances lie in an interval of 3.366(1)–3.337(1) .__________Translated from Koordinatsionnaya Khimiya, Vol. 31, No. 4, 2005, pp. 266–272.Original Russian Text Copyright © 2005 by Glazunova, Boltalin, Troyanov.     

Thiolate-bridged heterometallic complexes of manganese and platinum: Synthesis and molecular structures of (CO)4Mn(μ-SPh)Pt(PPh3)2, (CO)3(PPh3)Mn(μ-SPh)Pt(PPh3)(CO), and (CO)3Mn(μ-SPh)Pt(PPh3)(Dppm)

A reaction of the dimer [Mn(CO)₄(SPh)]₂ with (PPh₃)₂Pt(C₂Ph₂) gave the heterometallic complex (CO)₄Mn(μ-SPh)Pt(PPh₃)₂ (I) and its isomer (CO)₃(PPh₃)Mn(μ-SPh)Pt(PPh₃)(CO) (II). A reaction of complex I with a diphosphine ligand (Dppm) yielded the heterometallic complex (CO)₃Mn(μ-SPh)Pt(PPh₃)(Dppm) (III). Complexes I–III were characterized by X-ray diffraction. In complex I, the single Mn-Pt bond (2.6946(3) ?) is supplemented with a thiolate bridge with the shortened Pt-S and Mn-S bonds (2.3129(5) and 2.2900(6) ?, respectively). Unlike complex I, in complex II, one phosphine group at the Pt atom is exchanged for one CO group at the Mn atom. The Mn-Pt bond (2.633(1) ?) and the thiolate bridge (Pt-S, 2.332(2) ?; Mn-S, 2.291(2) ?) are retained. In complex III, the Mn-Pt bond (2.623(1) ?) is supplemented with thiolate (Pt-S, 2.341(2) ?; Mn-S, 2.292(2) 0?) and Dppm bridges (Pt-P, 2.240(1)?; Mn-P, 2.245(2) ?). Apparently, the Pt atom in complexes I–III is attached to the formally double bond , as in Pt complexes with olefins.     

Synthesis and structural characterisation of the palladium N-heterocyclic carbene cluster complexes [Pd3(μ-CO)3(NHC)3] and [Pd3(μ-SO2)3(NHC)3]

The reduction of trans-[Pd(NHC)₂Cl₂] (NHC = IMes, 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene; IⁱPr₂ = 1,3-bis-isopropylimidazol-2-ylidene) with potassium graphite under an atmosphere of CO affords the palladium NHC carbonyl clusters [Pd₃(μ-CO)₃(NHC)₃] (NHC = IMes, 1; IⁱPr₂, 3). Treatment of 1 with SO₂ at room temperature yields the bridging SO₂ complex [Pd₃(μ-SO₂)₃(IMes)₃] (4) in quantitative yield. Complexes 1, 3 and 4 have been structurally characterised by X-ray crystallography.     

trans-dinitro- and trans-dinitratoruthenium complexes [RuNO(NH3)2(NO2)2(OH)] and [RuNO(NH3)2(H2O)(NO3)2]NO3·H2O

Methods for the synthesis of trans-diammino complexes [RuNO(NH₃)₂(NO₂)₂(OH)] (I) and [RuNO(NH₃)₂(H₂O)(NO₃)₂](NO₃)·H₂O (II) are suggested. The compounds were studied by IR spectroscopy and X-ray phase and X-ray structural analyses. Crystal data: space group P-1; a = 6.2328(2) ?, b = 11.0488(3) ?, c = 11.0981(4) ?, α = 71.942(1)°, β = 83.291(1)°, γ = 86.877(1)° (I); space group P2₁; a = 6.6290(2) ?, b = 13.4389(5) ?, c = 7.0180(2) ?, β 114.281(1)° (II). Complex II readily lost some part of crystal water on storage in open air. Original Russian Text Copyright ? 2009 by M. A. Il’in, E. V. Kabin, V. A. Emel’yanov, I. A. Baidina, and V. A. Vorob’yov __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 50, No. 2, pp. 341–348, March–April, 2009.     

Phenyltellurenyl halide complexes of ruthenium and rhenium (CO)2RuBr2(PhTeBr)2 and (CO)3Re(PhTeI)3(μ3-I): Synthesis and crystal and molecular structures

Reactions of Ru₃(CO)₁₂ with PhTeBr₃ and of Re(CO)₅Cl with PhTeI in benzene give the stable complexes (CO)₂RuBr₂(PhTeBr)₂ (I) and (CO)₃Re(PhTeI)₃(μ³-I) (II) containing two and three ligands PhTeX (X = Br or I), respectively. The bonds between these ligands and the central metal atom are fairly shortened (on average, Ru-Te, 2.608 ?; Re-Te, 2.7554(12)-2.7634(13) ?). The Te-X bonds in the ligands PhTeBr (2.5163(5) ?) and PhTeI (2.7893(15) ?) are not lengthened appreciably. In complex II, the iodide anion is not coordinated by rhenium, yet being attached through weak secondary bonds to three Te atoms of the three ligands PhTeI.     

Synthesis,X-ray crystal structure and thermal decomposition of two peroxovanadium complexes with coordinated ammonia molecules: [{VO(O2)2(NH3)}2{μ-Cu(NH3)4}] and [Zn(NH3)4][VO(O2)2(NH3)]2

The compounds [{VO(O₂)₂(NH₃)}₂{μ-Cu(NH₃)₄}] (1) and [Zn(NH₃)₄][VO(O₂)₂(NH₃)]₂ (2) were prepared and characterized by elemental analysis and infrared spectra. The single crystal X-ray study revealed that the structure of 1 consists of trinuclear complex molecules [(NH₃)OV(O₂)₂{μ-Cu(NH₃)₄}(O₂)₂VO(NH₃)] with a rare heterobimetalic peroxo bridge: copper(II)–peroxo ligand–vanadium(V). The structure of 2 is composed of tetraamminezinc(II) cations and ammineoxodiperoxovanadate(V) anions. In course of thermal decomposition of 1 performed up to 620 °C, the following intermediate products: [Cu(NH₃)₂(VO₃)₂], and subsequently a mixture of V₂O₅ with monoclinic β-Cu₂V₂O₇, were gradually formed. The final product of decomposition is Cu(VO₃)₂. The thermal decomposition of 2 is a two-step process. In the first stage, [Zn(NH₃)₃(VO₃)₂] as supposed intermediate was formed, which transformed at higher temperatures by release of ammonia molecules to the monoclinic modification of Zn(VO₃)₂.     

Addition and/or oxidation in the reaction of a tricobalt cluster with silver(I) salts: synthesis, structure and solution properties of [Co3Cp3(μ3-CPh)2{μ-Ag(X)}] (X=CF3CO2, NO3) and [Co3Cp3(μ3-CPh)2{μ-Ag(NCMe)}]PF6

Reactions of the benzylidyne-capped tricobalt cluster [Co₃Cp₃(μ₃-CPh)₂] (1) with various silver salts have been examined. The salts of weakly- or non-coordinating anions (e.g., BF₄⁻ and PF₆⁻) oxidize 1 in CH₂Cl₂ to form its cationic radical, 1⁺. Reactions with salts of strongly coordinating anions (e.g., CF₃CO₂⁻ and NO₃⁻) yield the silver(I) adducts of 1, [Co₃Cp₃(μ₃-CPh)₂{μ-Ag(X)}] (for X=CF₃CO₂⁻: 2 and NO₃⁻: 3). Even with AgBF₄ or AgPF₆, the reaction in MeCN produces a silver(I) adduct, [Co₃Cp₃(μ₃-CPh)₂{μ-Ag(NCMe)}]⁺ (4⁺). The Co₃Ag skeleton in the structures of 2, 3, and 4⁺ is similar in each compound. The Co-Co bond bridged by the Ag atom (for 2, Co-Co=2.4785(8) Å, for 3, Co-Co=2.4837(9) Å, and for 4⁺, Co-Co=2.4578(7) Å) is longer than the average Co-Co bond length in 1 where 〈Co-Co〉_av=2.382(8) Å. The other Co-Co bonds in the compounds are slightly shorter than those in 1. The Co₂Ag triangle is not coplanar with the Co₃ triangle; the dihedral angles between these triangles for 2, 3 and 4⁺ are 162.7°, 157.7°, and 151.6°, respectively. Dissolution of 4PF₆ in CH₂Cl₂ leads to the formation of 1⁺ and the deposition of Ag metal. The ¹H NMR spectra of 2 and 3 in CD₂Cl₂ indicate that the AgX group moves over the three Co-Co bonds. The ESR spectra in frozen acetonitrile solutions of 2, 3, and 4PF₆ show the existence of a small amount of 1⁺, but the deposition of Ag metal was not observed.     

The crystal structure of Yb2(SO4)3·3H2O and its decomposition product, β-Yb2(SO4)3

Yb₂(SO₄)₃·3H₂O, synthesised by hydrothermal methods at 220(2) °C, has been investigated by single crystal X-ray diffraction. Yb₂(SO₄)₃·3H₂O crystallises in space group Cmc2₁ and is isostructural with Lu₂(SO₄)₃·3H₂O. The crystal structure has been refined to R₁=0.0145 for 3412 reflections [F_o>3σ(F)], and 0.0150 for all 3472 reflections. The structure of Yb₂(SO₄)₃·3H₂O is a complex framework of YbO₆ octahedra, YbO₈ and YbO₅(H₂O)₃ polyhedra and SO₄ tetrahedra. Thermal data shows that Yb₂(SO₄)₃·3H₂O decomposes between 120 and 190 °C to form β-Yb₂(SO₄)₃. The structure of a twinned crystal of β-Yb₂(SO₄)₃ was solved and refined using an amplimode refinement in R3c with an R₁=0.0755 for 8944 reflections [F_o>3σ(F)], and 0.1483 for all 16,361 reflections. β-Yb₂(SO₄)₃ has a unique structural topology based on a 3D network of pinwheels.     

A laser flash photolysis, matrix isolation, and DFT investigation of (η-C6H5Y)Cr(CO)3 (Y = NH2, OCH3, H, CHO, or CO2CH3)

The quantum yield for arene displacement from (η⁶-C₆H₅Y)Cr(CO)₃ was measured in 1,1,2-trifluorotrichloroethane (Y = NH₂, OCH₃, H, CHO, or CO₂CH₃). Values of 0.24, 0.27, 0.15, 0.17, and 0.32 were obtained respectively (λ_exc. = 355 nm). These values are significantly higher than those measured for photoinduced arene loss in hydrocarbon solvents using the same excitation wavelength. Laser flash photolysis of (η⁶-C₆H₅Y)Cr(CO)₃ in 1,1,2-trifluorotrichloroethane (λ_exc. = 355 nm) resulted in the rapid formation (<10 ns) of Cr(CO)₆. Matrix isolation experiments on (η⁶-C₆H₅Y)Cr(CO)₃ (Y = H or CHO) at 12 K in CH₄ or CO-doped CH₄ matrixes using monochromatic irradiation confirmed the presence of two discrete excited states, one leading to CO-loss and the other to arene-loss. The results correlate with the calculated electron drift in the excited state derived from density functional theory and time dependent density functional theory calculations.     

Synthesis and crystal structure of new one-dimensional copper(II) complex [Cu4(En)2(μ1,1-N3)4(μ1,1,1-N3)2(μ1,3-N3)2]n

A new polymer azido-bridged copper(II) complex [Cu₄(En)₂(μ_1,1-N₃)₄(μ_1,1,1-N₃)₂(μ_1,3-N₃)₂] _n (I) (En = ethylenediamine) has been synthesized and crystallography characterized. Complex I shows one-dimensional coordination polymeric structure based on a tetranuclear cluster unit [Cu₄(En)₂(μ_1,1-N₃)₄(μ_1,1,1-N₃)₂(μ_1,3-N₃)₂], in which the azido ions display three different bridging modes.     

Two new zincophosphates, (H3NCH2CH2NH3)2[Zn(μ-PO4)2] and (NH4)[(H3N)Zn{(μ-PO4)Zn}3]: Crystal structures and relationships to similar open framework zinco- and aluminophospates

Two new zincophosphates, bis(ethylenediammonim) catena-bis(μ-phosphato)zincate, (H₃NCH₂CH₂NH₃)₂[Zn(μ-PO₄)₂] (1), and ammonium ammine-tris(μ-phosphato)tetrazincate, (NH₄)[(H₃N)Zn{(μ-PO₄)Zn}₃] (2), were synthesized under hydrothermal conditions and their crystal structures were determined by single-crystal X-ray diffraction analysis. The crystal structure of 1 consists of infinite macroanionic ZnP₂O₈⁴⁻ chains, running along the [0 0 1] direction, and diprotonated ethylenediammonium cations, H₂en²⁺. The crystal structure of 2 is built up from ZnO₄, Zn(NH₃)O₃ and PO₄ vertex-sharing tetrahedra connected to form an open 3D framework. The ammonium groups, NH₄⁺, are located in the channels formed by 8M-rings extending along [1 0 0]. In order to study vibrational behavior of H₂en²⁺ and NH₄⁺ cations, NH₃ molecules in 1 and 2, single-crystal Raman spectra were obtained. Structural, chemical and topological similarities to the other open framework zinco- and aluminophosphates incorporating different guest species are discussed.     

A comparative study of [Co(NH3)5ONO]XY?[Co(NH3)5NO2]XY (XY=Cl2, Br2, I2, (NO3)2 Cl; NO3) solid-state isomerization kinetics

Quantitative IR investigation of solid-state [Co(NH₃)₅ONO]XY[Co(NH₃)₅NO₂]XY (XY=Cl₂, Br₂, I₂, (NO₃)₂ Cl; NO₃) linkage isomerization in KBr pellets has shown the kinetics to depend upon the outer-sphere anion. The red shift of the ₅(ONO) band during isomerization is a linear function of transformation degree.     

Crystal structure of K2[Mo3(PdPPh3)S4(C2O4)3(H2O)3]·0.5H2O

By the reaction of [Mo₃S₄(C₂O₄)₃(H₂O)₃]²⁻ with PdCl₂ and NH₄H₂PO₂ as a reducing agent, followed by the addition of PPh₃, a new oxalate cuboidal cluster complex [Mo₃(PdPPh₃)S₄(C₂O₄)₃(H₂O)₃]²⁻ is obtained. It was isolated and structurally characterized as K₂[Mo₃(PdPPh₃)S₄(C₂O₄)₃(H₂O)₃]·0.5H₂O. Original Russian Text Copyright ? 2008 by A. L. Gushchin, M. N. Sokolov, D. Yu. Naumov, and V. P. Fedin __________ Translated from Zhurnal Strukturnoi Khimii, Vol. 49, No. 4, pp. 775–778, May–June, 2008.     

Synthesis and molecular structures of the Co3(μ-OOCPh)4(μ,η2-OOCPh)2[OC(Ph)OHNEt3]2 and Co(Hdmpz)2(OOCPh)2 complexes (Hdmpz = 3,5-dimethylpyrazole)

The product of the thermal reaction between cobalt acetate hydrate and benzoic acid reacts with a triethylamine excess to form the trinuclear complex Co₃(μ-OOCPh)₄(μ,η²-OOCPh)₂[OC(Ph)OHNEt₃]₂, and its reaction with 3,5-dimethylpyrazole yields the mononuclear complex Co(Hdmpz)₂(OOCPh)₂. The compound structures are discussed on the basis of X-ray crystallographic data.     

Synthesis and Crystal Structure of the Heterovalent Copper(I,II) π-Complex Cu7Br6.48Cl1.52 ? 2C3N3(OC3H5)3

Single crystals of the heterovalent Cu^I,Cu^II π,σ-complex Cu₇Br_6.48Cl_1.52 ⋅ 2C₃N₃(OC₃H₅)₃ are synthesized by the ac electrochemical method from an ethanol solution containing 2,4,6-triallyloxy-1,3,5-triazine, CuCl₂ ⋅ 2H₂O, and CuBr₂. The unit cell parameters of the crystals are: space group , a = 8.271(3) Å, b = 11.391(3) Å, c = 11.821(3) Å, α = 67.43(1)°, β = 84.41(2)°, γ = 85.14(2)°, V = 1022(1) ų, and R(F) = 0.0714. The copper and halogen atoms form unique moieties Cu₆X₆ linked by bridging fragments [Cu²⁺ (C₃N₃(OC₃H₅)₃)₂]X₂ into infinite chains. Each inorganic moiety Cu₆X₆ is linked with four 2,4,6-triallyl- oxy-1,3,5-triazine molecules. The ligand molecule is coordinated to one Cu^II atom through the nitrogen atom of the triazine cycle and to two Cu^I atoms through the C=C bonds of two allyl groups. The Br content equal to 0.57 in the X(4) position linking the Cu^I and Cu^II atoms differs markedly from a value of 0.85–0.91 for the X(1), X(2), and X(3) positions linked only with the Cu(I) atoms.__________Translated from Koordinatsionnaya Khimiya, Vol. 31, No. 6, 2005, pp. 455–461.Original Russian Text Copyright © 2005 by Goreshnik, Schollmeyer, Mys’kiv.     

Synthesis,structure characterization and thermal properties of [Zr6(μ3-O)4(μ3-OH)4(OOCCH2Bu)9(μ2-OH)3]2

Oxo/hydoxo zirconium(IV) complex of the general formula [Zr₆(μ₃-O)₄(μ₃-OH)₄(OOCCH₂^tBu)₉(μ₂-OH)₃]₂ has been isolated, when Zr(OⁱPr)₄ reacted with a 2-fold excess of 3,3-dimethylbutyric acid. Single crystal X-ray diffraction data, collected at 103 and 153 K, showed that the studied compound crystallizes in hexagonal system (P6₃/m (no. 176)). Structure consists of dimers composed of [Zr₆(μ₃-O)₄(μ₃-OH)₄(OOCCH₂^tBu)₉] sub-units, linked by six μ₂-OH bridges. Infrared spectroscopic studies proved the presence of hydroxo groups in the structure of studied clusters and formation of different types of oxo/hydroxo bridges. The application of variable temperature infrared spectroscopy and differential scanning calorimetry revealed that the structure of this complex undergoes the phase transitions at 143–183 and 203–293 K. Comparison of spectral and crystallographic data suggests that these phase transitions might be related to changes in the strength of Zr–O bonds of μ₂-OH bridges linking complex sub-units, and change in symmetry of the crystal lattice (from hexagonal to trigonal). Analysis of thermogravimetric data showed that decomposition of [Zr₆(μ₃-O)₄(μ₃-OH)₄(OOCCH₂^tBu)₉(μ₂-OH)₃]₂ proceeds with complete conversion to ZrO₂ (monoclinic form) between 603 and 803 K.     

Complexes of technetium(I) (Tc, Tc) pentacarbonyl core with π-acceptor ligands (tert-butyl isocyanide and triphenylphosphine): Crystal structures of [Tc(CO)5(PPh3)]OTf and [Tc(CO)5(CNC(CH3)3)]ClO4

A procedure was developed for preparing [^99mTcX(CO)₅] (X = Cl, Br, I) in a reasonable yield by high-pressure carbonylation with CO of ^99mTcO₄⁻ in aqueous solutions. In the synthesis, the substantial part of the target product is accumulated in the gas phase and can be transferred from the autoclave into various solvents when relieving the pressure. Compounds [^99mTcX(CO)₅] (X = Cl⁻, Br⁻, I⁻) are stable in solutions for several hours, but in the course of longer storage they gradually decompose to give the tricarbonyl species. Substitution of the halide ligands in [⁹⁹TcX(CO)₅] and [^99mTcX(CO)₅] with tert-butyl isocyanide and triphenylphosphine was studied. The structures of the complexes [Tc(CO)₅(PPh₃)]OTf and [Tc(CO)₅(CNC(CH₃)₃)]ClO₄ are presented.     

Investigations on the thermal behaviour of [Ni(NH3)6](NO3)2 and [Ni(en)3](NO3)2 using TG–MS and TR-XRD under inert condition

Thermal behaviour of hexaamminenickel(II) nitrate and tris(ethylenediamine)nickel(II) nitrate have been investigated by means of simultaneous thermogravimetry/DTA coupled online with mass spectral (MS) studies and temperature resolved X-ray diffraction (TR-XRD) techniques under inert atmospheric condition. Both the complexes produce highly exothermic reactions during heating due to the oxidation of the evolved ammonia or ethylenediamine by the decomposition products of Ni(NO₃)₂. Evolved gas analysis by MS studies detected fragments like NH₂ and NH ions with weak intensity. The decomposition of nitrate group generates N, N₂, NO, O₂ and N₂O species. Ethylenediamine (m/z 60) is fragmented to H₂ (m/z 2), N (m/z 14), NH₃ (m/z 17) and CH₂=CH₂/N₂ (m/z 28) species. The formation of the intermediates was monitored by in situ TR-XRD. The residue of thermal decomposition for both the complexes was found to be crystalline NiO in the nano range.