Synthesis,characterization and reactions of the transition metal halogenoalkyl carbocation complexes [Cp(CO)2M{η2-CH2CH(CH2)nX}]PF6 (n = 1–8, 10, M = Fe; n = 3, 4 M = Ru; X = Br,I)

The halogenoalkyl complexes [Cp(CO)₂M{(CH₂)_nX}] (n = 3–10, 12, M = Fe; n = 5, 6, M = Ru, X = Br, I) react with Ph₃CPF₆ in dry CH₂Cl₂ to give the corresponding carbocation complexes [Cp(CO)₂M{η²-(CH₂CH(CH₂)_n?2X}]PF₆ in high yields. NMR evidence indicates that the metals form metallacyclopropane type structures with the carbocation ligand. The reactions of some of the cationic complexes with NaI, PPh₃, Na[Cp(CO)₂Fe] and Et₃N are discussed. NaI and Na[Cp(CO)₂Fe] displace the halogeno-olefin, while PPh₃ adds at the β-CH^δ+ giving the unstable phosphonium adducts [Cp(CO)₂Fe{CH₂CH(PPh₃)(CH₂)_n?2X}]PF₆ which decompose to the halogeno-olefins and the cationic PPh₃ complex [Cp(CO)₂Fe(PPh₃)]⁺. Et₃N causes allylic deprotonation forming internal olefin complexes of the type [Cp(CO)₂Fe{CH₂CHCH(CH₂)_n?3X}]PF₆.     

Diels-Alder reaction with cyclopentadiene and electronic structures of (η5-cyclopentadienyl)M(CO)x(η1-N-maleimidato) (M = Fe,Mo, W,x = 2 or 3)

Diels-Alder reaction of (η⁵-cyclopentadienyl)M(CO)_x(η¹-N-maleimidato) complexes (M = Fe, Mo, W, x = 2 or 3) with cyclopentadiene has been studied. The observed order of reactivity was: N-ethylmaleimide > W complex > Mo complex > Fe complex. The X-ray structures of the adducts have been determined for M = W and Fe. DFT calculations on the starting complexes have been performed to explain the observed reactivity order.     

Rare-Earth Substituted Polyoxoanions: [{La(CH3COO)(H2O)2(α2-P2W17O61)}2]16− and [{Nd(H2O)3(α2-P2W17O61)}2]14−

The lanthanum-substituted polyoxometalate [{La(CH₃COO)(H₂O)₂( ₂-P₂W₁₇O₆₁)}₂]^16– (1) and the neodymium-substituted species [{Nd(H₂O)₃( ₂ -P₂W₁₇O₆₁)}₂]^14– (2) have been synthesized and characterized by IR spectroscopy and elemental analysis. Single-crystal X-ray analysis was carried out on K₁₆[{La(CH₃COO)(H₂O)₂( ₂ -P₂W₁₇O₆₁)}₂]36H₂O, which crystallizes in the triclinic system, space group P¯1, with a=12.3863(6) Å, b=12.8934(6) Å, c=31.7285(14) Å, =84.2000(10)°, =81.2300(10)°, =61.6500(10)°, and Z=1; K_6.5Nd_2.5[{Nd(H₂O)₃( ₂-P₂W₁₇O₆₁)}₂]55H₂O, which crystallizes in the monoclinic system, space group P2 ₁ /n, with a=17.5030(9) Å, b=23.7842(12) Å, c=19.1869(10) Å, =100.6610(10)°, and Z=1. The head-on, trans-oid dimer 1 consists of two ( ₂ -P₂W₁₇O₆₁)^10– fragments connected by a lanthanum-acetate dimer, (La₂(CH₃COO)₂(H₂O)₄)⁴⁺. Each La³⁺ ion is nine-coordinated in a monocapped, square-antiprismatic fashion. The neodymium-derivative 2 is also a trans-oid dimer, but the mode of binding is different from 1 and is best described as side-on. Each Nd³⁺ ion is eight-coordinated in a square-antiprismatic fashion with three terminal water molecules.     

Energy decomposition analysis of the metal-imine bond in [(CO)4M–SB] (M = Cr,Mo, W; SB: RHCN–CH2CH2–NCHR)

The electronic and molecular structures of the metal-Schiff base complexes [(CO)₄M–SB] (M: Cr, Mo, W; SB: RHCN–CH₂CH₂–NCHR, R = C₆H₅, C₆F₅, Ortho-, Meta- and Para-XC₆H₄ (X = F, Cl, Br,CH₃)) have been investigated at the DFT level using the exchange correlation functional BP86. The nature of the TM?Schiff base interactions was analyzed with charge and energy decomposition methods. The octahedral equilibrium geometries have C_2v symmetry. The (CO)₄M–SB bond dissociation energies vary little for different substituents R. The calculated values indicate rather strong bonds which exhibit the trend for the different metals M = Mo (D_e = 59.8–65.4 kcal/mol) < Cr (D_e = 62.3–67.8 kcal/mol) < W (D_e = 69.9–75.8 kcal/mol). The energy decomposition analysis suggests that the (CO)₄M–SB attractive interactions come mainly from electrostatic attraction which provide ～60% to ?E_int while ～40% come from orbital interactions. The latter term arises mainly (～70%) through (CO)₄M ← SB σ donation from the nitrogen lone-pair orbitals while a much smaller part (～20%) comes from (CO)₄M→SB π backdonation. The transition metals carry large negative partial charges between ?2.3 e for M = Cr and ?1.1e for M = W.     

Zur addition des thiomethyl-kations an die Wolfram-Kohlenstoff-Doppelbindung in [Cp(CO)(PMe3)WC(Tol)PR2][PF6]

Carbonyl(η⁵-cyclopentadienyl)(trimethylphosphine)[η²-(dimethylphenylphosphino-4-methylphenylcarbene]tungsten hexafluorophosphate reacts with dimethyl(methylthio)sulfonium tetrafluoroborate to yield the dicationic complexes tungstaphosphathiabicyclo[1.1.0]butane.     

Helical chains of [MO5Cl] octahedra – Three compounds in the new family AEM2Te3O8Cl2 (AE = Ca,Sr and M = Co,Ni)

The compounds CaCo₂Te₃O₈Cl₂, SrCo₂Te₃O₈Cl₂ and SrNi₂Te₃O₈Cl₂ were synthesized via solid–gas reactions and investigated using single-crystal X-ray diffraction. While the compound CaCo₂Te₃O₈Cl₂ formed large enough single crystals to allow for a detailed structural analysis, crystals of the Sr-containing compounds yielded evidence that they are isostructural. CaCo₂Te₃O₈Cl₂ crystallizes in the monoclinic system, space group P2₁/c, a = 6.537(2) Å, b = 9.088(2) Å, c = 19.500(9) Å, β = 113.36(4)°, Z = 4. It exhibits [CoO₅Cl] helical chains along the [010] direction, connected by [CaO₈] polyhedra, [TeO₃E] tetrahedra and [TeO₄E] trigonal bipyramids (the lone pair of electrons on Te^IV is designated as E) to form a layer. The layers are held together only by weak van der Waals forces; the shortest interlayer distance is a Te?Cl contact of 3.432(4) Å.     

Tetracarbonyliron adducts of Cp2Cr2(CO)4(μ-η2-P2). Syntheses and crystal structures of Cp2Cr2(CO)4P2[Fe(CO)4] m (m=1 and 2)

Cp₂Cr₂(CO)₄( - ² - P₂), 1, reacts with one molar equivalent of Fe₂(CO)₉ in THF to yield the mono- and di-iron complexes, Cp₂Cr₂(CO)₄P₂[Fe(CO)₄], 2, (16.5% yield) and Cp₂Cr₂(CO)₄P₂[Fe(CO)₄]₂, 3, (16.9% yield), as dark magenta brown and dark greenish brown crystals, respectively. Both complexes were characterized by single-crystal X-ray diffraction analysis. Crystal data –2: space group =P2₁/c,a=17.024(1) Å,b=8.180(1) Å,c=30.891(2) Å, =100.953(5)°,V=4223.4(7)ų,Z=8, 3743 observed reflections,R _F=0.033; 3: space group P1,a=10.209(2) Å,b=10.212(2) Å,c=15.989(3) Å, =106.93(1)°, =91.87(1)°, =119.50(1)°,V=1356.5(4) ų,Z=2, 3489 observed reflections,R _F=0.029.     

Cp Me5P6C5[M(CO)5]3: Ungewöhnliche reaktion des tricyclischen hexaphosphans Cp2P6 mit M(CO)5thf (M = Cr,W)

3,4-Bis[pentamethylcyclopentadienyl]tricyclo-[3.1.0.0^2,6] hexaphosphane 1 reacts with Cr(CO)₅thf or W(CO)₅thf to give the zwitterionic chromium complex 1,9,10-tris(pentacarbonylchromium)−3,4,5,6,11-pentamethyl-7-pentamethylcyclopentadienyl-3,4,5,6,11-pentacarba-penta-cyclo-[6.1. 1.^1,8.1^3,6.O^2,7.0^10,11 ]-4-en-7-ium-9-id-undeca-phosphane 2 and the analogous tungsten compound 3, respectively. The basic structures of 2 and 3 are similar to the cunean-moiety of the Hittorf-modification of phosphorus.     

Relative permittivity increments for {xCH3OH + (1 − x)CH3OCH2(CH2OCH2)3CH2OCH3} fromT = 283.15 K toT = 323.15 K

Relative permittivities of { CH₃OH  +  CH₃OCH₂(CH₂OCH₂)₃CH₂OCH₃(2,5,8,11,14-pentaoxapentadecane, tegdme)} at temperatures from 283.15 K to 323.15 K and atmospheric pressure, were measured over the whole composition range. Experimental relative permittivities were fitted by a polynomial function in mole fraction. Values of relative permittivity were measured using a HP4284A precision LCR Meter together with the measuring cell HP16452A at 1 MHz. Relative permittivity increments were determined from experimental data and fitted to a variable-degree polynomial function. Different theoretical models were used to predict the permittivity of this mixture. The predictions are better when the volume change on mixing is considered.     

Three K[M(salen)(CN)2]-based trinuclear sandwich-like heterobimetallic M(III)–Cu(II) (M = Fe,Cr, Co) complexes: synthesis,crystal structures,and magnetic properties

Transition Metal Chemistry - Three trans-dicyanoiron(III) precursors K[M(salen)(CN)2] (M&nbsp;=&nbsp;Fe, Cr or Co; H2salen&nbsp;=&nbsp;N,N′-bis(salicyl)ethylenediamine) and...     

New triosmium–iridium clusters: Synthesis and molecular structure of [Os3Ir2(Cp1)2(μ-OH)(μ-CO)2(CO)8Cl] (1), [Os3IrCp1(μ-OH)(CO)10Cl] (2), [Os3IrCp1(μ-H)(μ-Cl)(η3,μ3-C5H2N(NH2)Br)(CO)9] (3) and [Os3IrCp1(μ-Cl)2(η2,μ3-C5H3N(NH)Br)(CO)7] (4)

The trinuclear osmium carbonyl cluster, [Os₃(CO)₁₀(MeCN)₂], is allowed to react with 1 equiv. of [IrCp¹Cl₂]₂ (Cp¹ = pentamethylcyclopentadiene) in refluxing dichloromethane to give two new osmium–iridium mixed-metal clusters, [Os₃Ir₂(Cp¹)₂(μ-OH)(μ-CO)₂(CO)₈Cl] (1) and [Os₃IrCp¹(μ-OH)(CO)₁₀Cl] (2), in moderate yields. In the presence of a pyridyl ligand, [C₅H₃N(NH₂)Br], however, the products isolated are different. Two osmium–iridium clusters with different coordination modes of the pyridyl ligand are afforded, [Os₃IrCp¹(μ-H)(μ-Cl)(η³,μ₃-C₅H₂N(NH₂)Br)(CO)₉] (3) and [Os₃IrCp¹(μ-Cl)₂ (η²,μ₃-C₅H₃N(NH)Br)(CO)₇] (4). All of the new compounds are characterized by conventional spectroscopic methods, and their structures are determined by single-crystal X-ray diffraction analysis.     

Ternary mutual diffusion coefficients of aqueous {l-dopa (1) + β-CD (2)} solutions at T = 298.15 K

Ternary mutual diffusion coefficients (D₁₁, D₂₂, D₁₂ and D₂₁) measured by the Taylor dispersion method are reported for aqueous solutions of {levodopa (l-dopa) + β-cyclodextrin (β-CD)} solutions at T = 298.15 K and concentrations up to 0.007 mol · dm⁻³. Significant effects on the diffusion were observed, suggesting interactions between this carbohydrate and l-dopa. Support for this came from ¹H NMR spectroscopy, which shows that these effects are due to formation of 1:1 (β-CD:l-dopa) complexes.     

First Examples of Electrophilic Addition to a Fe2Q Face of [Fe3(μ3-Q)(CO)9]2− (Q=Se, Te)—Synthesis and Characterisation of [MFe3(μ4-Q)(CO)9Cp*] and [IrFe2(μ3-Q)(CO)7Cp*] (M=Rh, Ir; Cp*=η5-C5(CH3)5)

The reaction of [Et₄N]₂[Fe₃(μ ₃-Q)(CO)₉] (Q=Se ([Et₄N]₂[1b]), Te ([Et₄N]₂[1c])) with [Cp*M(CH₃CN)₃][CF₃SO₃]₂ (M=Rh, Ir) leads to the addition of a Cp*M²⁺ unit to a Fe₂Q face of the initial cluster. In this way four new heteronuclear clusters [MFe₃(μ ₄-Q)(CO)₉Cp*] (M=Rh (2b, c); M=Ir (3b, c)) were obtained possessing a butterfly-shaped cluster core bridged by a μ ₄-Q unit. Furthermore, reaction with the Ir starting complex leads to the metal-substituted derivatives [IrFe₂(μ ₃-Q)(CO)₇Cp*] (4b, c) in lower yields, whose structures consist of a triangular metal core capped by a μ ₃-Q ligand. The products were comprehensively characterised by spectroscopic methods and the molecular structures of 2b, 3c, and 4c were established by single crystal X-ray diffraction measurements.     

[Na·6THF][Cp_3Nd(μ-H)NdCp_3]·2THF配合物的合成与分子结构

Rossmanith报导,无水NdCl_3和萘锂在THF溶液中可生成NdCl_2·2THF。我们在研究这一类型化合物时考察了NdCl_3·2THF和CpNa(Cp为环戊二烯)在THF中的反应,分离出一种氢化物——[Na·6THF][Cp_3Nd(μ-H)NdCp_3]·2THP。这个配合物性能非常活泼,可以与含活泼氢的有机化合物作用使C-C及C-H键断裂。本文报导此配合物的合成及其分子结构,应当指出,1986年Schumann等人曾合成[Na·6THF][Cp3Lu(μ-H)LuCp3]·2THF,发现该配合物极不稳定,无法进行元素分析,对H桥的特征吸收峰亦未进行确切的归属。本文的标题化合物也有同样的问题。     

Synthesis and Crystal Structure of [Cis-1,10phenanthroline-palladium(Ⅱ)(THF)_2]dinitrate (THF = Tetrahydrofuran)

1 INTRODUCTION The coordination chemistry of Pd(Ⅱ) com- plexes with didentate nitrogen coordination ligands has been extensively studied for a few decades[1]. Pd(Ⅱ) trends to bond to the didentate nitrogen in cis-mode and such complexes have potential usage in the emerging area of self-assembly[2]. We will report herein the synthesis and crystal structure of a cis-coordinated mononuclear Pd(Ⅱ) complex with one 1,10-phenanthroline and two THF as ligands, 1. 2 EXPERIMENTAL 2. …     

Reactions of [WI2(CO)(NCMe)(η2-RC2R)2] (R = Me or Ph) with carbon monoxide to give either [WI2(CO)2(η2-MeC2Me)2] or [W(-I) I(CO) (η2-PhC2Ph)2]2. Crystal structure of [WI2(CO) 2( η2-MeC2Me)2]

The complexes [WI₂(CO)(NCMe)(η2)-RC₂R)₂] (R = Me and Ph) react in CH₂Cl₂ with an excess of carbon monoxide to give initially the acetonitrile substituted products [WI₂(CO)₂(η²-RC₂R) ₂]. For R= Me, the complex [WI₂(CO)₂(η²- MeC₂Me)₂] (1) was isolated and its structure determined by X-ray crystallography. However, for R = Ph, dimerisation occurs to give the iodide-bridged compound [W(μ-I)I(CO)(η²-PhC₂Ph)₂]₂ (2) with loss of carbon monoxide. These reactions are reversible as 1 and 2 react with acetonitrile to give [WI₂(CO)(NCMe)(η²-RC₂R)₂]. The ¹³C NMR spectra of I and 2 indicate that the two alkyne ligands donate a total of six electrons to the tungsten in these complexes.     

CRYSTAL STRUCTURE OF [Cu(bpy)3] [{Cu(bpy)}2Re4Se4(CN)12]·3.5H2O

Journal of Structural Chemistry - Chain coordination polymer [Cu(bpy)3][{Cu(bpy)}2Re4Se4(CN)12]·3.5H2O (1) is obtained by the reaction of K4[Re4Se4(CN)12]·6H2O with CuCN and...     

Reaction of {HC(CMeNAr)2}Li (Ar=2,6-i-Pr2C6H3) with indium monochloride to yield the InIn bonded dimer [{HC(CMeNAr)2}InCl]2 and the hydroxide [{HC(CMeNAr)2}InCl(μ-OH)]2

The reaction of the sterically encumbered lithium β-diketiminate {HC(CMeNAr)₂}Li (Ar=2,6-i-Pr₂C₆H₃) with InCl in THF at approximately −78 °C yielded In metal and [{HC(CMeNAr)₂}InCl]₂ (1) as well as minor amounts of the hydroxide [{HC(CMeNAr)₂}In(Cl)(μ-OH)]₂, 2. The compounds 1 and 2 were characterized by ¹H, ¹³C NMR, IR spectroscopy and X-ray crystallography. The centrosymmetric structure of 1 features an InIn bond that is 2.8343(7) Å long which is well within the known range of InIn single bond distances. The metal β-diketiminate ring (i.e. C₃N₂In) is folded along the N⋯N vector and features an out of plane deviation by the indium of 0.8953 Å and a dihedral angle between the C₃N₂ and InN₂ arrays of 145.8°. This can be attributed to steric effects of the Ar groups on the β-diketiminiate ligand. The structure of the hydroxide derivative 2 is a dimer in which the indiums are bridged by hydroxides to afford a planar In₂O₂ core with an average InO distance of 2.13(2) Å. Attempted reduction of the dihalide compounds {HC(CMeNAr)₂}InX₂ (X=Cl, I) with sodium or potassium led to the formation of metallic indium and the free β-aminoimine (Ar)NC(Me₂)CHC(Me₂)N(Ar)H rather than the desired In(I) species, {HC(CMeNAr)₂}In:.     

Mixed-ligand guanidinate derivatives of rare-earth metals. Molecular structures of { (Me3Si)2NC(N-cyclo-Hex)2}Y[N(SiMe3)2]2, [{ (Me3Si)2NC(N-cyclo-Hex)2}YbI(THF)2]2, and [{(Me3Si)2N} Y(THF)(µ-Cl)]2 complexes

The insertion of N,N′-dicyclohexylcarbodiimide at one of the Y-N bonds of the [(Me₃Si)₂N]₃Y complex in toluene at 70 °C afforded the monoguanidinate diamide derivative { (Me₃Si)₂NC(N-cyclo-Hex)₂}Y[N(SiMe)₃]₂ (1) (cyclo-Hex is cyclohexyl) in 72% yield. The reaction of equimolar amounts of sodium N,N′-dicyclohexyl-N″-bis(trimethylsilyl)guanidinate, which was prepared in situ from {(Me₃Si)₂N}Na and N,N′-dicyclohexylcarbodiimide, and YbI₂(THF)₂ in THF gave the [{(Me₃Si)₂NC(N-cyclo-Hex)₂}YbI(THF)₂]₂ complex (2). An attempt to use this procedure for the synthesis of the yttrium compound { (Me₃Si)₂NC(NSiMe₃)₂}₂YCl containing the sterically more hindered guanidinate ligand unexpectedly led to the formation of the diamide chloride complex [{(Me₃Si)₂N}₂Y(THF)(µ-Cl)]₂ (3). The structures of complexes 1–3 were established by X-ray diffraction. Compound 1 is mononuclear. Complexes 2 and 3 are dinuclear and contain two µ²-bridging halide ligands.