Syntheses and X-ray Characterization of Novel [M4(H2O)2(XW9O34)2] n− (M=CuII, X=CuII; and M=FeIII, X=FeIII) Polyoxotungstates

Two novel examples of sandwich type heteropolyanions were synthesized and characterized by X-ray crystal structure and elemental analysis as well as infrared spectroscopy. Na₁₃[H₃Cu₄(H₂O)₂(CuW₉O₃₄)₂]39H₂O (1) and Na₉K[Fe₄(H₂O)₂(FeW₉O₃₄)₂]32H₂O (2) were prepared in aqueous solution by reaction of sodium tungstate with Fe^III and Cu^II cations, respectively. 1 crystallizes in the monoclinic space group P2₁/n (a=13.054(3) Å, b=17.729(4) Å, c=20.998(4) Å, =93.50(3)°), while 2 is triclinic, space group P¯1 (a=12.316(2) Å, b=13.716(3) Å, c=14.925(3) Å, =99.36(3)°, =104.21(3)°, =101.55(3)°). Each anion consists of two [XW₉O₃₄] ^n– moieties (X=Fe^III, n=11 (1) and Cu^II, n=12 (2)) which can be described as -B-isomers of the defect Keggin anion. These units are linked via a belt of four Fe^IIIO₆ or Cu^IIO₆ groups. Two transition metal atoms fill their octahedral coordination sphere with one additional water ligand.     

[M(dap)3]2(Sb2Se5)·xH2O(M=Ni,x=2;M=Zn,x=0)的溶剂热合成及晶体结构

利用溶剂热法合成了2种新的有机杂化锑硒化合物[Ni(dap)3]2(Sb2Se5)].2H2O(1)和[Zn(dap)3]2(Sb2Se5)](2)(dap=1,2-丙二胺),单晶X射线衍射分析结果表明,1属于三方晶系,P3121空间群,晶胞参数为a=10.7574(14),b=10.7574(14),c=31.672(4),γ=120.00°,z=4。2属于单斜晶系,P21空间群,晶胞参数为a=10.772(2),b=16.391(3),c=11.704(2),β=100.912(4)°,z=4。在2种化合物中,Ni2 与Zn2 离子分别与3个dap配体螯合形成畸变八面体几何构型,其中dap配体的N原子是无序的,而二聚[Sb2Se5]2-阴离子是由2个SbSe3三角锥共用1个Se原子连接而成。     

Homoleptic diphosphacyclobutadiene complexes [M(η(4)-P2C2R2)2]x- (M = Fe, Co; x = 0, 1)

The preparation and comprehensive characterization of a series of homoleptic sandwich complexes containing diphosphacyclobutadiene ligands are reported. Compounds [K([18]crown-6)(thf)(2)][Fe(η(4)-P(2)C(2)tBu(2))(2)] (K1), [K([18]crown-6)(thf)(2)][Co(η(4)-P(2)C(2)tBu(2))(2)] (K2), and [K([18]crown-6)(thf)(2)][Co(η(4)-P(2)C(2)Ad(2))(2)] (K3, Ad = adamantyl) were obtained from reactions of [K([18]crown-6)(thf)(2)][M(η(4)-C(14)H(10))(2)] (M = Fe, Co) with tBuC[triple bond]P (1, 2), or with AdC[triple bond]P (3). Neutral sandwiches [M(η(4)-P(2)C(2)tBu(2))(2)] (4: M = Fe 5: M = Co) were obtained by oxidizing 1 and 2 with [Cp(2)Fe]PF(6). Cyclic voltammetry and spectro-electrochemistry indicate that the two [M(η(4)-P(2)C(2)tBu(2))(2)](-)/[M(η(4)-P(2)C(2)tBu(2))(2)] moieties can be reversibly interconverted by one electron oxidation and reduction, respectively. Complexes 1-5 were characterized by multinuclear NMR, EPR (1 and 5), UV/Vis, and M?ssbauer spectroscopies (1 and 4), mass spectrometry (4 and 5), and microanalysis (1-3). The molecular structures of 1-5 were determined by using X-ray crystallography. Essentially D(2d)-symmetric structures were found for all five complexes, which show the two 1,3-diphosphacyclobutadiene rings in a staggered orientation. Density functional theory calculations revealed the importance of covalent metal-ligand π bonding in 1-5. Possible oxidation state assignments for the metal ions are discussed.     

Interactions of M(z)-X complexes (M = Cu, Ag, and Au; X = He, Ne, and Ar; and z = ±1)

The coupled cluster singles and doubles method with perturbative treatment of triple excitations is applied to calculate the potentials of M(z)-X complexes (M = Cu, Ag, and Au; X = He, Ne, and Ar; and z = ±1). The bond functions and the basis set superposition errors are considered to obtain accurate interaction energies. The potential energy curves of all complexes are obtained. The vibrational energy levels and the spectroscopic parameters for these complexes are determined. The analytical potential energy functions are also fitted based on the potential energies.     

氧心羧桥异三核过渡金属簇合物[Fe2MO(CH3COO)6Py3].Py(1,M=Mn;2,M=Co;3,M=Ni)和[Fe2MO(CCl3COO)6(THF)3](4,M=Mn;5,M=Co;6,M=Ni)电子光谱的研究

The UV/VIS spectra for pyridine solution of complexes [Fe_2MO(CH_3COO)_6Py_2]·Py and THF solution of complexes Fe_2MO(CCl_3COO)_6(THF)_3 were studied. The d-d transitions were assigned and the ligand field parameters(B,D_q,β) were calculated for the related metal ions according to ligand field theory (Tanabe-Sugano diagram) in terms of O_h symmetry and reasonably good fits were obtained for the calculated and observed frequencies. The calculated results show that (1) the larger the ionic potential for M~(2+) ion, the larger the values of B, D_q for Fe~(3+) ion (2) the ligand field parameters of metal ions vary in parallel with the electronagativity of R in RCOO~-.     

氧心羧桥异三核过渡金属簇合物[Fe_2MO(CH_3COO)_6Py_3]·Py(1,M=Mn;2,M=Co;3,M=Ni)和[Fe_2MO(CCl_3COO)_6(THF)_3](4,M=Mn;5,M=Co;6,M=Ni)电子光谱的研究

氧心羧桥三核物通式为[M_3O(RCOO)_6L_3]~(n+)(n=1,0)虽然它在三十年代就已合成出来,但是引起人们广泛兴趣的还是近年来发现的它所具有的特殊稳定性和不寻常的物理化学性质。我们测定了不同M~(2+)离子,两种羧桥的铁系列异三核标题簇合物的晶体结构和有关物理性质。该类型化合物的结构可以看成由共享μ_3-O顶点的三个金属离子的配位八面体组     

Synthesis and characterization of cobalt(II) and manganese(II) xylaratogermanates: The molecular and crystal structures of the [M(H2O)6][Ge(μ3-L)2{M(H2O)2}2] · 4H2O · nCH3CN Complexes (M = Co, n = 0; M = Mn, n = 1)

A synthetic procedure was developed, and heteropolynuclear coordination compounds—the products of the interaction of germanium tetrachloride with xylaric (trihydroxyglutaric) acid HOOC-CH(OH)-CH(OH)-CH(OH)-COOH (H₅L) and the acetates of the 3d metals Mn(II) and Co(II)—were prepared. The compounds were characterized by elemental analysis, thermogravimetry, and IR spectroscopy. The X-ray diffraction analysis of the [M(H₂O)₆][Ge(μ₃-L)₂{M(H₂O)₂}₂] · 4H₂O · nCH₃CN complexes, where M = Co, n = 0 (I) and M = Mn, n = 1 (II), was performed. The crystals of I are monoclinic, a = 10.752(2) Å, b = 11.830(2) Å, and c = 10.772(2) Å, β = 94.741(3)°, V = 1365.4(5) ų, Z = 2, space group P2₁/n, R1 = 0.0309 for 3200 reflections with I > 2σ(I). The crystals of II are triclinic, a = 9.5330(17) Å, b = 9.7415(17) Å, and c = 10.3935(18) Å, α = 115.024(2)°, β = 97.580(3)°, γ = 111.535(3)°, V = 764.9(2)ų, Z = 1, space group $P\bar 1$ , R1 = 0.0621 for 3028 reflections with I > 2σ(I). The bimetallic anions [Ge(μ₃-L)₂{M(H₂O)₂}₂]^2?, the cations [M(H₂O)₆]²⁺, and crystal water molecules form the basis of compounds I and II (the acetonitrile molecule is also a constituent of compound II). In the centrally symmetrical trinuclear complex anion, the Ge(1) atom is bound to two M(1) atoms through two completely deprotonated bridging ligands. The Ge(1) atom is coordinated to the six alcohol oxygen atoms of two ligands L^5? at the apexes of a distorted octahedron (the average Ge(1)-O distances in I and II are 1.8858(14) and 1.892(3)Å, respectively). The coordination polyhedron of the M(1) atom in the complex anion is a strongly distorted octahedron. The base of the coordination polyhedron is formed by the two bridging alcohol oxygen atoms (the average M(1)-O distances in I and II are 2.1756(14) and 2.255(3) Å, respectively) of two L^5? ligands and by the oxygen atoms of two water molecules (the average M(1)-O distances in I and II are 2.0693(17) and 2.175(4) Å, respectively). In the centrally symmetrical complex cation, the coordination polyhedron of the M(2) atom is a somewhat distorted octahedron. The M(2)-O(H₂O) bond lengths in I and II vary in the ranges of 2.0137(17)-2.1555(17) and 2.140(5)-2.172(4) Å, respectively (the average lengths are 2.0375(17) and 2.166(4) Å, respectively). The cations and anions are joined by a branched system of hydrogen bonds.     

Stable π-π dependent electron conduction band of TPP[M(Pc)L2]2 molecular conductors (TPP = tetraphenylphosphonium; M = Co, Fe; Pc = phthalocyaninato; L = CN, Cl, Br)

The partially-oxidized TPP[M(Pc)L(2)](2) molecular conductors exhibit variable electronic and magnetic transport bulk materials properties due to central metal and axial ligand molecular modifications. The controllable electrical conductivity and giant negative magnetoresistance can be mainly attributable to the varying ligand field energy and physical bulkiness of the axial ligands which cause modulation in the intra-molecular π-d (Pc-M) and inter-molecular π-π (Pc-Pc) interactions in the TPP[M(Pc)L(2)](2) system, respectively. Characterization of the electronic conduction band utilizing one-dimensional (1-D) tight-binding approximation from infrared reflectance and thermoelectric power profile reveal consistent band widths of 0.43 eV-0.62 eV for the Co series (L = Br < Cl < CN) and 0.44-0.56 eV for the Fe series (L = Br < Cl < CN). The fixed band width suggests that stable electron conduction bands (transport pathway) can be constructed which can withstand the molecular π-d interaction modifications that severely alter the bulk electronic and magnetic materials properties of the TPP[M(Pc)L(2)](2) molecular conductors.     

Synthesis and Crystal Structure of [Cu3(dmpzm)4(μ-1,3-dca)2(dca)4]·2H2O (dmpzm = 1,1·-Methylenebis-(3,5-dimethyl-1H-pyrazole), dca = dicyanamide)

The title compound, [Cu3(dmpzm)4(μ-1,3-dca)2(dca)4]·2H2O (dmpzm = 1,1'-methyle- nebis(3,5-dimethyl-1H-pyrazole), dca = dicyanamide) 1·2H2O, was synthesized via the reaction of CuCl2·2H2O with dmpzm and Na(dca), and characterized by elemental analysis and IR spectra. 1·2H2O crystallizes in the monoclinic system, space group C2/m with a = 13.578(3), b = 16.769(3), c = 14.769(3)(A),β=104.10(3)°, V = 3261.4(11)(A)3, Z = 2, Dc = 1.466 g/cm3, T = 153(2) K, C56H68N34O2Cu3, Mr = 1440.09, F(000) = 1490, μ(MoKα) = 1.040 mm(1, S = 1.150, R = 0.0553 and wR = 0.1123 for 2744 observed reflections with I > 2σ(I). The central copper atom is chelated by two dmpzm ligands and coordinated by two bridging dca anions, forming a slightly distorted octahedral geometry. The two external copper atoms adopt a square-pyramidal coordination geometry, coor- dinated by one chelating dmpzm ligand and one bridging and two terminal dca anions. Two inter- molecular hydrogen bonding interactions result in the formation of a 2D (4,4) hydrogen-bonded network.     

Formation of M(4)Se(4) cuboids (M = As, Sb, Bi) via secondary pnictogen-chalcogen interactions in the co-crystals MX(3)·Se[double bond, length as m-dash]P(p-FC(6)H(4))(3) (M = As, X = Br; M = Sb, X = Cl; M = Bi, X = Cl, Br)

The reactions of the group 15 trihalides, MX(3) (M = As, Sb, Bi; X = Cl, Br), with the phosphine selenide SeP(p-FC(6)H(4))(3) result in the formation of co-crystals of formula MX(3)·SeP(p-FC(6)H(4))(3). No reaction was observed with MI(3) (M = As, Sb, Bi). The structures of MX(3)·SeP(p-FC(6)H(4))(3) (M = As, X = Br 2; M = Sb, X = Cl 3; M = Bi, X = Cl 5; M = Bi, X = Br 6) have been established, and are isomorphous, crystallising in the cubic I23 space group. All the structures feature a primary MX(3) unit, which has three weak secondary MSe interactions to SeP(p-FC(6)H(4))(3) molecules. However, each of these SeP(p-FC(6)H(4))(3) molecules bridges three MX(3) molecules, resulting in the generation of an M(4)Se(4) (M = As, Sb, Bi) distorted cuboid linked by the pnictogen-chalcogen interactions. Four opposing corners of the cuboid are occupied by the M atom (M = As, Sb, Bi) of an MX(3) pyramid, and the other four by the selenium atom of the phosphine selenide.     

Synthesis,structure, and electrochemical properties of [M(N-MeIm)6]2+ (M = Ni,Co, Cu) associated with [HgCl4]2−

Reaction of Hg(NO₃)₂ with 4 equivalent KI in water afford K₂[HgI₄]. By using K₂[HgI₄] as the precursor, three new heterobimetallic compounds [Ni(N-MeIm)₆][HgI₄] (I), [Co(N-MeIm)₆][HgI₄] (II), and [Cu(N-MeIm)₆][HgI₄] (III) have been characterized by elemental analysis, IR spectra, and the singlecrystal X-ray crystallorgraphy analysis. Three complexes are isomorphous and crystallized in monoclinic symmetry space group P2₁/c. The coordination around each center metal(II) atom is octahedral with six nitrogen atoms of N-MeIm ligand. Each structure contains one tetrahedral [HgI₄]^2? as an anion to balance the charge of the molecular. Thermogravimetry analysis indicates these complexes have the similar departure process and cyclic voltammogram exhibits a significant pair of redox peaks.     

Synthesis,Crystal Structures,and Properties of (4,4'-Hbipy)2[Sn2(C2O4)3] and (4,4'-Hmbipy)[SnX2] (X = C2O42–, m = 2; X = Cl,m = 0; bipy = bipyridine)

Three new tin coordination compounds (4,4'-Hbipy)₂[Sn₂(C₂O₄)₃] ( 1 ), (4,4'-H₂bipy)[Sn(C₂O₄)₂] ( 2 ), and SnCl₂(4,4'-bipy) ( 3 ) were synthesized under hydro-(solvo-)thermal conditions and their crystal structures were determined by single-crystal X-ray diffraction. Compound 1 exhibits a ionic structure based on discrete [4,4'-Hbipy]⁺ cations and [Sn₂(C₂O₄)₃]^2– anions. These two units are linked via N–H ··· O hydrogen bonds to form a pseudo-one-dimensional zigzag hydrogen-bonded chain. In compound 2 , four-coordinate Sn atoms form monomeric tin dioxalato complexes, which are connected to the doubly protonated [4,4'-H₂bipy]²⁺ cations through N–H ··· O hydrogen bonded to give a one-dimensional zigzag hydrogen-bonded chain. Compound 3 forms a three-dimensional hydrogen-bonded network, in which ¹_∞[SnCl₂(4,4'-bipy)] linear chains are interconnected to each other by C–H ··· Cl hydrogen bonding. The solid-state UV/Vis/NIR diffuse reflectance spectroscopy shows that three compounds are broadband semiconductors. The thermogravimetric analysis evidences the thermal stability of the three compounds up to 175, 201, and 246 °C, respectively.     

Synthesis,crystal structure,and properties of [Cu(LH)]2[M(mnt)2] [M = Ni or Cu; H2L = 3,3′-(1,3-propanediyldinitrilo)-bis(2-butanone oxime); mnt2− = maleonitriledithiolate] complexes containing bridging cyano groups

Interesting complexes containing a mnt^2– bridge, based on the reaction of [M(mnt)₂]^2– [M = Ni or Cu] with [Cu(LH)]⁺, have been prepared and characterized by e.s.m.s., i.r and u.v–vis. spectroscopic techniques and by electrochemistry. The complexes show weak antiferromagnetic interactions between magnetic centers. The X-ray analysis of the molecular structure of [Cu(LH)]₂[Ni(mnt)₂] has been completed. It structurally features the CN group of mnt^2– which can act as a bridging ligand between two transition metals.     

The photo-induced decarbonylation of Cp′M(NO)(CO)2 (M = Cr,Mo, W) with diorgano dichalcogenides (R2E2; E = S,Se; R = Me,Ph)

The photo-induced decarbonylation of CpCr(NO)(CO)₂ (1a) in MeCN solution in the presence of R₂E₂ (E = S, Se; R = Me, Ph) leads to the formation of chalcogenolato-bridged binuclear complexes Cp₂Cr₂(NO)₂(-ER)₂ [E = S; R = Me (2a), Ph (3a); E = Se, R = Me (4a), Ph (5a)] while reactions between CpM(NO)(CO)₂ [M = Mo (1b), W (1c)] and Ph₂E₂ (E = S, Se) result in mononuclear complexes CpM(NO)(EPh)₂ [M = Mo; E = S (9b), Se (10b); M = W, E = S (11c), Se (12c)]. The corresponding reactions of (1b) with Me₂E₂ (E = S, Se) yielded both mono and binuclear complexes: CpMo(NO)(SeMe)₂ (8b), Cp₂Mo₂(NO)₂(-EMe)₂ [E = S (6b), Se (7b)]. The new complexes have been characterized by i.r., ¹H-, ¹³C-n.m.r. spectra and by electron-impact mass spectrometry.     

Synthesis and characterization of one-dimensional coordination polymers, [M(sac)2(μ–pyz)(H2O)2] n [M=ZnII,CdII, pyz = pyrazine,and sac = saccharinate]

Two new coordination polymers, [M(sac)₂(μ–pyz)(H₂O)₂] _n [M=Zn^II(1), Cd^II(2), pyz =?pyrazine, and sac =?saccharinate], have been prepared and characterized by elemental analysis, FTIR spectroscopy, thermal analysis and single crystal X-ray diffraction. Both complexes are isomorphous and crystallize in the triclinic P 1 space group. The metal(II) ions are octahedrally coordinated by two sac, two aqua and two pyz ligands. The sac ligands are N-coordinated, while the pyz ligands are bridges between the metal centers, leading to one-dimensional linear chains. Intra-chain M–M separations in 1 and 2 are 7.218 and 7.498 Å, respectively. The individual chains are linked by strong OW–H ··· O(sac) hydrogen bonds into two–dimensional layers, which are further assembled into three–dimensional supramolecular networks by aromatic π(sac) ··· π(sac) stackings interactions.     

The preparation and spectral properties of the new ‘mixed’ complexes [MI2(CO)3(py)L] (M = Mo and W; L = PPh3, AsPh3 and SbPh3)

Abstract

Seven-coordinate complexes of molybdenum(II) and tungsten(II) have become increasingly important as homogeneous catalysts. For example, the complexes [MX₂(CO)₃L₂] (M = Mo and W; X = Cl and Br; L = PPh₃ and AsPh₃) have been shown to be catalysts for the ring-opening polymerisation of norbornene.¹ Although a wide variety of complexes of the type [MX₂(CO)₃L₂] (M = Mo and W; X = Cl, Br and I; L = nitrogen, phosphorus, arsenic and antimony donor ligands)² have been reported, until now no examples of the mixed complexes [MX₂(CO)₃(py)L] have been prepared. In this communication we wish to describe the synthesis of the new mixed pyridine/L compounds [MI₂(CO)₃(py)L] (M = Mo and W; L = PPh₃, AsPh₃ and SbPh₃).     

Carbene complexes of molybdenum and tungsten Et3E-CH=M(NAr)(OR)2 (M = Mo, W; E = Si, Ge) and π-complex of molybdenum (RO)2(ArN)Mo(CH2=CH-GeEt3). Synthesis and catalytic properties

The heteroelement-containing alkylidene imide complexes with molybdenum and tungsten Et₃SiCH=Mo(NAr)(OR)₂ (I), Et₃ ECH=W(NAr)(OR)₂ (E = Si (II), Ge (III); Ar = 2,6-i-Pr₂C₆H₃; R=CMe₂ CF₃) and π-complex (RO)₂(ArN)Mo(CH₂=CH-GeEt₃) (IV) were synthesized by the reaction of Alkyl-CH=M(NAr) (OR)₂ (M=Mo, W; Alkyl = t-Bu, PhMe₂C) with organosilicon and organogermanium vinyl reagents Et₃ECH=CH₂ (E = Si, Ge). The structure of compounds I–III was determined by X-ray diffraction (XRD). The complexes I–IV are active initiators of metathesis polymerization of cycloolefins.     

DFT evaluation of the electronic structures and spectroscopic properties of the self-assembled [Pt2M4(C ≡ CH)8] (M=Cu,Ag) clusters

Science China Chemistry - Electronic structures and spectroscopic properties of self-assembled [Pt2M4(C≡CH)8] (M=Cu, Ag) clusters have been studied by the TD-DFT (time-dependent density...     

OXO-CENTERED HETEROTRINUCLEAR TRANSITION METAL CARBOXYLATE COMPLEXES 3, SYNTHESES AND X-RAY STRUCTURAL CHARACTERISTICS OF COMPOUNDS Fe_2MO(O_2CCCl_3)_6(THF)_3 (1,M = Mn;2,M=Co;3, M = Ni;THF=TETRAHYDROFURAN)

<正> The title compounds have been synthesized and characterized by x-ray analysis. They are isomorphous, belonging to trigonal space group R3m,with crystallo-graphic parameters; (1)α =b =c= 13. 713(5) A ;α= β=γ=83. 66(3)°;V = 2535A3;Z = 2;DC=1. 80gcm-3;F(000) = 1358;M= 1373. 23;(2)α= b = c=13. 687(2) A;α = β = γ = 84. 27(1)°/;V = 2528. 0A3;Z = 2; Dc = 1. 81gcm-3; F (000)= 1362; M = 1377. 23;(3)α = b=c=13. 671(6) A ;α = β = γ=84. 12(3)°;V=2518A3;Z=2;DC = 1. 82 gcm-3;F(000)= 1364;Mr= 1376. 99.The structure of comp ound 2 has been determined with the final R= 0. 061 for 845 reflections with I≥3σ(Ⅰ).The three metal atoms are crystallographically equivalent because of the arbitrariness of orientation of the molecules,and in the sense of crystallography the molecule Fc2CoO(O2CCCl3)6(THF)3 is of C3vsymmetry with centered oxygen atom on the 3-fold axis. The atoms M,C(1~4),C1(1) and O(1) lie on the mirror. Three CC13 groups on one side the Fe2CoO plane and three terminal THF ligands are dynamically