Aluminum(III) Cations [(NHC) ⋅ AlMes2]+: Synthesis,Characterization, and Application in FLP-Chemistry

The three-coordinate aluminum cations ligated by N-heterocyclic carbenes (NHCs) [(NHC) ⋅ AlMes₂]⁺[B(C₆F₅)₄]⁻ (NHC=IMe^Me 4 , IiPr^Me 5 , IiPr 6 , Mes=2,4,6-trimethylphenyl) were prepared via hydride abstraction of the alanes (NHC) ⋅ AlHMes₂ (NHC=IMe^Me 1 , IiPr^Me 2 , IiPr 3 ) using [Ph₃C]⁺[B(C₆F₅)₄]⁻ in toluene as hydride acceptor. If this reaction was performed in diethyl ether, the corresponding four-coordinate aluminum etherate cations [(NHC) ⋅ AlMes₂(OEt₂)]⁺ [B(C₆F₅)₄]⁻ 7 – 9 (NHC=IMe^Me 7 , IiPr^Me 8 , IiPr 9 ) were isolated. According to a theoretical and experimental assessment of the Lewis-acidity of the [(IMe^Me) ⋅ AlMes₂]⁺ cation is the acidity larger than that of B(C₆F₅)₃ and of similar magnitude as reported for Al(C₆F₅)₃. The reaction of [(IMe^Me) ⋅ AlMes₂]⁺[B(C₆F₅)₄]⁻ 4 with the sterically less demanding, basic phosphine PMe₃ afforded a mixed NHC/phosphine stabilized cation [(IMe^Me) ⋅ AlMes₂(PMe₃)]⁺[B(C₆F₅)₄]⁻ 10 . Equimolar mixtures of 4 and the sterically more demanding PCy₃ gave a frustrated Lewis-pair (FLP), i.e., [(IMe^Me) ⋅ AlMes₂]⁺[B(C₆F₅)₄]⁻/PCy₃ FLP-11 , which reacts with small molecules such as CO₂, ethene, and 2-butyne.     

The Synthesis of the Arene Clusters Ru6C(CO)14(η6-Arene) (Arene = C6H5CHMe2, C6H5C4H9, C6H5C3H7, and C6H5C3H5)

On reaction with Ru₃(CO)₁₂, isopropenylbenzene and 4-phenyl-l-butene undergo hydrogenation, to yield the clusters, Ru₆C(CO)₁₄(⁶-C₆H₅CHMe₂) 1 and Ru₆C(CO)₁₄(⁶-C₆H₅C₄H₉) 2, respectively. With allylbenzene, both hydrogenation and isomerization occurs affording Ru₆C(CO)₁₄(⁶-C₆H₅C₃H₇) 3 and Ru₆C(CO)14(⁶-C₆H₅C₃H₅) 4. The structures of 1 and 2 have been established by single crystal X-ray diffraction. One of the Ru–Ru bond lengths in 2 is unusually long and extended Hückel molecular orbital calculations have been used in an attempt to rationalize this feature.     

[(C6H5 NO2)Pr(H2O)4](CrMo6O24H6)·(C6H5NO2)·2.5H2O的合成与晶体结构

用常规合成方法制备了基于Anderson结构阴离子的二维层状化合物[(C6H5NO2)2Pr(H2O)4](CrMo6O24H6)·2.5H2O,通过红外光谱和X射线单晶衍射对其进行了表征.结果表明,该化合物属于单斜晶系,C2/c空间群.a=2.3442(9)nm,b=1.3291(5)nm,c=2.458(1)nm,β=103.08(1)°,V=7.460(5)nm3,R1=0.0727,wR2=0.1903.结构分析表明,[CrMo6O24H6]3-阴离子通过端氧担载一个配位的Pr3+离子形成中性的(C6H5NO2)Pr(H2O)4(CrMo6O24H6)基团,相邻的中性基团在Ot—Pr—Ot桥联下形成一维链,链与链又通过异烟酸的桥联形成二维层状结构.     

[(CO)2(C5H5)Fe]2C60的合成与表征

有关 C6 0 取代的金属羰基化合物的研究方兴未艾 .C6 0 作为一个特殊的烯烃 ,以六元环间的碳碳双键提供电子对 ,与过渡金属羰基化合物形成诸如 η2 ,η4 ,η6等结构新颖的化合物约有 40多例 [1～ 5] ,但只有一例是以 Fe为中心原子的 C6 0 取代的金属羰基化合物 ( η2 - C6 0 ) Fe( CO) 4 [1] .本文报道了第一例 C6 0配位的 Fe的双核金属羰基化合物 [( CO) 2 ( C5H5) Fe]2 (η2 - C6 0 ) ,并通过元素分析 ,IR,1H NMR,13CNMR和 XPS进行表征 .1　实验部分[Fe( CO) 2 ( C5H5) ]2 购自 Aldrich公司 .C6 0 纯度为 99% .其余试剂均…     

Synthesis of the first anionic derivatives of Hf(CO)7: [(C5h5)Hf(CO)4]− and [(C5Me5)Hf(CO)4]−

Potassium naphthalenide reductions of [(C₅R₅)HfCl₃] (R  H, Me) in 1,2-dimethoxyethane at −60°C followed by carbonylation at atmospheric pressure provide 25–50% isolated yields of the first examples of carbonyl anions of hafnium(0), [(C₅H₅)Hf(Co)₄]⁻ and [(C₅Me₅)Hf(CO)₄]⁻. These were isolated as tetraethylammonium salts as well as K(cryptand-2.2.2) and K(15-Crown-5)₂⁺ salts for the latter anion and now represent two of only four presently known Hf⁰ carbonyls. They were characterized by elemental analyses, IR and ¹H and ¹³C NMR spectra.     

Tieftemperatur-flüssigphasefluorierung von pentafluorphenyl-element-Verbindungen. Darstellungen und eigenschaften von (C6F5)3AsF2, (C6F5)3SbF2, (C6F5)2SeF2, (C6F5)2SeO,C6F5TeF3 und Cs[(C6F5)3EF3] (E = As,Sb) [1]

The fluorination reactions of (C₆F₅)₃E (E = As, Sb) with elemental flourine yield (C₆F₅)₃EF₂ in high yields. From the reactions of (C₆F₅)₃EF₂ with CsF the new salts Cs[(C₆F₅)₃EF₃] are obtained. (C₆F₅)₂SeF₂ and C₆F₅TeF₃ are formed for the first time by reacting (C₆F₅)₂SeF and (C₆F₅)₂TeF₂ with elemental flourine and XeF₂, respectively. (C₆F₅)₂SeF₂ rapidly reacts with glass, and the new compound (C₆F₅)₂SeO is isolated. The preparations, properties and ¹⁹F NMR spectra of the new compounds are described.     

Why are [P(C6H5)4](+)N3- and [As(C6H5)4](+)N3- ionic salts and Sb(C6H5)4N3 and Bi(C6H5)4N3 covalent solids? A theoretical study provides an unexpected answer

A recent crystallographic study has shown that, in the solid state, P(C(6)H(5))(4)N(3) and As(C(6)H(5))(4)N(3) have ionic [M(C(6)H(5))(4)](+)N(3)(-)-type structures, whereas Sb(C(6)H(5))(4)N(3) exists as a pentacoordinated covalent solid. Using the results from density functional theory, lattice energy (VBT) calculations, sublimation energy estimates, and Born-Fajans-Haber cycles, it is shown that the maximum coordination numbers of the central atom M, the lattice energies of the ionic solids, and the sublimation energies of the covalent solids have no or little influence on the nature of the solids. Unexpectedly, the main factor determining whether the covalent or ionic structures are energetically favored is the first ionization potential of [M(C(6)H(5))(4)]. The calculations show that at ambient temperature the ionic structure is favored for P(C(6)H(5))(4)N(3) and the covalent structures are favored for Sb(C(6)H(5))(4)N(3) and Bi(C(6)H(5))(4)N(3), while As(C(6)H(5))(4)N(3) presents a borderline case.     

Heats of formation of C(6)H(5)(•), C(6)H(5)(+), and C(6)H(5)NO by threshold photoelectron photoion coincidence and active thermochemical tables analysis

Threshold photoelectron photoion coincidence has been used to prepare selected internal energy distributions of nitrosobenzene ions [C(6)H(5)NO(+)]. Dissociation to C(6)H(5)(+) + NO products was measured over a range of internal energies and rate constants from 10(3) to 10(7) s(-1) and fitted with the statistical theory of unimolecular decay. A 0 K dissociative photoionization onset energy of 10.607 ± 0.020 eV was derived by using the simplified statistical adiabatic channel model. The thermochemical network of Active Thermochemical Tables (ATcT) was expanded to include phenyl and phenylium, as well as nitrosobenzene. The current ATcT heats of formation of these three species at 0 K (298.15 K) are 350.6 (337.3) ± 0.6, 1148.7 (1136.8) ± 1.0, and 215.6 (198.6) ± 1.5 kJ mol(-1), respectively. The resulting adiabatic ionization energy of phenyl is 8.272 ± 0.010 eV. The new ATcT thermochemistry for phenyl entails a 0 K (298.15 K) C-H bond dissociation enthalpy of benzene of 465.9 (472.1) ± 0.6 kJ mol(-1). Several related thermochemical quantities from ATcT, including the current enthalpies of formation of benzene, monohalobenzenes, and their ions, as well as interim ATcT values for the constituent atoms, are also given.     

Fe3(CO)8[P[SC6H5)Cl2](μ3-S)2的合成和晶体结构

The title compound Fe_3(CO)_8 (P(SC_6H_5) Cl_2) (μ_3′-S)_2 was synthesised by reacting Fe_3(CO)_9 (μ_3-S)_2 with P (SC_6H_5) Cl_2. The crystal and molecular structure of the title compound has been determined by single crystal diffraction method. Crystal data: triclinic, space group P1, with a=0.7571(1), b=0.9097(1), c=1.7706(2) nm, α=95.03(1), β=101.79(1), γ=105.73(1)°, V =1.1359 nm, Z=2, Dc=1.935 g·cm~(-3). The structure was solved by direct method and difference Fourier synthesis, and refined by full-matrix least-squares with anisotropic thermal paramaters for non-hydrogen atoms, using 3724 observed reflections withI≥3σ(I). The final residual factor R=0.025, R_W=0.028.Fe_(CO)_8(P(SC_6H_5)Cl_2)(μ_3-s)_2 has a face-bridged 4e donors and the monosubstituted ligand is on the apical Fe atom.     

Substitution and insertion reactions of (η5-C5H5)Cr(CO)3C2H5

The complex (η⁵-C₅H₅)Cr(CO)₃Cp42 H₅ has been made and its reactions with σ donor ligands L (L = (MeO)₃P and (EtO)₃P) and with SO₂ studied. The alkyl phosphites give compounds of the composition (η⁵-C₅H₅)Cr(CO)₂LC₂H₅, and sulfur dioxide gives the corresponding S-sulfinato (η⁵-C₅H₅)Cr(CO)₃SO₂C₂H₅.     

N,N′-methylenedipyridinium Pt(II) and Pt(IV) hybrid salts: synthesis, crystal and molecular structures of [(C5H5N)2CH2] · [PtCl4] and [(C5H5N)2CH2] · [PtCl6]

The highly insoluble organic-inorganic hybrid ionic compounds N,N??-methylenedipyridinium tetrachloroplatinate(II) [(C₅H₅N)₂CH₂] · [PtCl₄] and N,N??-methylenedipyridinium hexachloroplatinate(IV) [(C₅H₅N)₂CH₂] · [PtCl₆] were obtained by the treatment of N,N??-methylenedipyridinium dichloride monohydrate [(C₅H₅N)₂CH₂]Cl₂ · H₂O with K₂[PtCl₄] or (NH₄)₂[PtCl₆], respectively, in an aqueous solution. Both complexes were isolated, purified, characterised by elemental analysis, and their molecular structures were confirmed by powder X-ray diffraction. The crystal structure of both compounds consists of separated discrete dications [(C₅H₅N)₂CH₂]²⁺ and anions [PtCl _n ]^2? (n = 4 or 6). As anticipated, the dications formed a butterfly shape consisting of two pyridine rings bound to the methylene group via their N atoms, while the Pt centre had a square planar geometry in [(C₅H₅N)₂CH₂] · [PtCl₄] and an octahedral coordination in [(C₅H₅N)₂CH₂] · [PtCl₆]. Interestingly, both crystal structures are stabilised by intermolecular C-H??Cl non-standard hydrogen bonds, ??-?? ring interactions between two pyridine rings of adjacent dications, and also by Cl-?? interactions.     

New electron-deficient alkene and alkyne derivatives of Ru5(μ5-C)(CO)15: The syntheses and crystal structure analyses of Ru5(μ5-C)(CO)13 [C2H2(CO2Me)2] and Ru5(μ5-C)(CO)15 [C2(CO2Me)2]

Treatment of carbido cluster Ru₅(μ ₅-C)(CO)₁₅ with Me₃NO in acetonitrile solution followed by addition of dimethyl maleate or dimethyl acetylene dicarboxylate affords new clusters Ru₅(μ ₅-C)(CO)₁₃[C₂H₂(CO₂Me)₂] (1) and Ru₅(μ ₅-C)(CO)₁₅[C₂(CO₂Me)₂] (2), respectively. Single crystal X-ray structural studies reveal that both complexes contain a wingtip-bridged butterfly pentametallic skeleton. In complex1 the maleate fragment is coordinated to one wingtip Ru atom through its carbon-carbon double bond and to the adjacent Ru atom by the formation of two O → Ru dative bonding interactions, while the acetylene dicarboxylate fragment in2 is best considered as acis-dimetallated alkene, linking one hinge Ru atom and the nearby Ru atom at the bridged position. Crystal data for1: space group P 4₂/n;a=20.199(6),c=13.941(3) Å,Z=8; finalR _F=0.025,R _w=0.026 for 3963 reflections withI>2σ(I). Crystal data for2: space group P2₁/n;a=9.634(3),b=20.062(6),c=17.372(5) Å,β=90.62(2)°,Z=4; finalR _F=0 033,R _w=0.036 for 4683 reflections withI>3σ(I).     

Crystal and molecular structure of the [Nd2(H2O)8(C6F5COO)6]·2H2O Compound

A compound with the composition Nd(C₆F₅COO)₃· H₂O (I) is prepared. Single crystals are grown, and their single crystal XRD analysis of the Nd₂(H₂O)₈(C₆F₅COO)₆]·2H₂O (II) compound is performed. The crystals are triclinic: a = 7.693(2) Å, b = 9.394(2) Å, c = 18.203(4) Å, α = 81.91(3)°, β = 84.41(3)°, γ = 88.97(3)°, Z = 1, d _x = 2.223 g/cm³. The structure is composed of symmetrical molecules of the binuclear [Nd₂(H₂O)₈(C₆F₅COO)₆] complex and crystallization water molecules. The C₆F₅COO^- ligands are monodentate and tridentate bridging- chelating, which results in a closure of two four-membered chelate cycles NdO₂C and a four-membered metal cycle Nd₂O₂. The NdO₉ polyhedron is a distorted one-capped tetragonal antiprism.     

Reactions of Zn bis-ferrocenyl-β-diketiminates with [Ph3C][B(C6F5)4

The ZnMe complexes of bis-ferrocenyl-β-diketiminate ligands are prepared and the reactions with [Ph(3)C][B(C(6)F(5))(4)] are found to yield the salts [H(Ph(3)C)C(MeC(N(C(5)H(4))FeCp)(2)ZnMe] [B(C(6)F(5))(4)] and [CH(2)=C(MeC(N(C(5)H(4))FeCp)(2)ZnMe][B(C(6)F(5))(4)], derived from electrophilic substitution and hydride abstraction.     

Reactions of trans-[Pt(H2){P(C6H11)3}2] with heterocumulenes. The crystal and molecular structure of trans-[Pt{P(C6H11)3}2(H){OCHC(C6H5)2}]

Trans-PtH₂(PCy₃)₂ (1) reacts with phenylisocyanate (2) and with diphenylketene (3) to yield the formamido complex (4) and the vinyloxo complex (5), respectively. The structure of 5 has been determined by X-ray diffraction.     

Fourier-transform Raman and infrared spectra and normal coordinate analysis of (C6H5)2BiCl and [N(CH3)4]+[(C6H5)2BiCl2]−

The vibrational properties of the diphenylbismuth(III) chloride compounds (C₆H₅)₂BiCl and [N(CH₃)₄]⁺[(C₆H₅)₂BiCl₂]⁻ have been investigated. A comprehensive assignment of the fundamental modes in the measured Fourier-transform Raman and infrared spectra has been carried out. Normal coordinate calculations of these compounds based on new X-ray crystal structure data have been performed to identify the BiCl stretching and bending vibrations of both compounds. For [N(CH₃)₄]⁺[(C₆H₅)₂BiCl₂]⁻ in the solid state, the ν_s(BiCl₂) and ν_as(BiCl₂) occur at 215 cm⁻ (Raman) and 237 cm⁻ (Raman), respectively, in good agreement with the calculated wavenumbers. The force constant calculation yields a BiCl stretching force constant of 0.89 × 10² N m⁻¹.     

Five- and six-membered palladacycles derived from [(η5-C5H5)Fe{(η5-C5H4)-CH=N-(C6H4-2-C6H5)}]

The reaction of the novel ferrocenyl Schiff base: [(η⁵-C₅H₅)Fe{(η⁵-C₅H₄)-CH=N-(C₆H₄-2-C₆H₅)}] (1) with Na₂[PdCl₄] and Na(CH₃COO)·3H₂O in a 1:1:1 molar ratio in methanol is reported. In this reaction two different di-μ-chloro-bridged cyclopalladated complexes: [Pd{[(η⁵-C₅H₃)-CH=N-(C₆H₄-2-C₆H₅)]Fe(η⁵-C₅H₅)}(μ-Cl)]₂ (2a) and [Pd{[(C₆H₄-2-C₆H₄)-N=CH-(η⁵-C₅H₄)]Fe(η⁵-C₅H₅)}(μ-Cl)]₂ (2b) can be formed depending on the experimental conditions. Compounds 2a and 2b, which differ in the nature of the metallated carbon atom (C_{sp²,ferrocene} or C_{sp²,biphenyl}, respectively), undergo cleavage of the ‘Pd(μ-Cl)₂Pd’ bridges in the presence of thallium (I) acetylacetonate, deuterated pyridine or triphenylphosphine giving the monomeric derivatives: [Pd(C^∧N)(acac)] (3a, 3b) and [Pd(C^∧N)Cl(L)] {with L=py- d₅(4a, 4b), PPh₃(5a, 5b)}. The reactions of 2 with 1,2-bis(diphenylphosphino)ethane (dppe) reveal that the two isomers (2a and 2b) exhibit different reactivity versus dppe. These results have been interpreted on the basis of steric effects.     

Reaction of Mo(CO)6 with Alkoxide: Synthesis and Structure of the Mo(0)-OR Complex [Et4N]3[Mo2(CO)6(μ-OC6H4OCH2C6H5)3]

The reaction of molybdenum hexacarbonyl with C6H5CH2OC6H4ONa and Et4NBr in CH3CN at 60 ℃ afforded the di-nuclear Mo(0) compound [Et4N]3[Mo2(CO)6(μ-OC6H4OCH2- C6H5)3] 1. 1 crystallizes in monoclinic, space group P21/c with a=15.359(2), b=18.378(3), c=24.952(2)(A), β=102.268(4)°, V=6882.3(16) (A)3, Mr=1348.34, Z=4, Dc=1.301 g/cm3, F(000)=2832 and μ= 0.424 mm-1. The final R=0.0606 and wR=0.1552 for 9396 observed reflections (Ⅰ ＞ 2σ(Ⅰ)). 1 contains a [Mo2O3]3- core in triangular bi-pyramidal configuration and each Mo atom adopts a distorted octahedral geometry with three carbon atoms from carbonyls and three μ-O atoms from C6H5CH2OC6H4O- bridging ligands. The Mo…Mo distance is 3.30(8) (A), indicating no metalmetal bonding. A formation pathway via forming a di-molybdenum(0) di-bridging OR compound [Mo2(μ-OR)2(CO)8]2- has been figured out and the reaction of Mo(CO)6 with alkoxide has also been discussed.     

The preparation of a series of ring-linked derivatives of [Fe2(η-C5H5)2(CO)2(μ-CO)2] starting from [Fe2η5,η5-C5H4CH(NMe3)CH(NMe2)C5H4}(CO)2(μ-CO)2]+ salts

The salts [Fe₂η⁵,η⁵-C₅H₄CH{NMe₃)CH(NMe₂)C₅H₄}(CO)₂(μ-CO)₂][X] (X = I or SO₃CF₃) are the synthetic precursors to a wide range of [Fe₂(η-C₅H₅)₂(CO)₂(μ-CO)₂] derivatives in which the two cyclopentadienyl ligands are joined by a two-carbon bridge.