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1.
Reaction of cis-[RuCl2(dppm)2] (dppm = 1,2-bis(diphenylphosphino)methane) with PhCCH and NaPF6 utilising methanol as solvent results in the formation of the η3-butenynyl complex [Ru(η3-PhCCCCHPh)(dppm)2][PF6] in good yield. Similar reactions with ButCCH and PrnCCH resulted in the corresponding alkyl-substituted complexes and all three of these compounds have been characterised by NMR spectroscopy and X-ray crystallography. The mechanism of this reaction has been probed by employing labelling experiments with both PhCCD and PhC13CH allowing the identity of possible intermediates in the reaction to be determined. Furthermore, [Ru(η3-PhCCCCHPh)(dppm)2][PF6] has been shown to be an effective regio- and stereo-selective catalyst for the dimerisation of PhCCH to Z-PhCCCHCHPh in the absence of solvent. In contrast, no evidence for the formation of alkyne coupling was obtained from the reaction of cis-[RuCl2(dppe)2] (dppe = 1,2-bis(diphenylphosphino)ethane) with PhCCH and NaPF6.  相似文献   

2.
The synthesis of the new complexes Cp*(dppe)FeCC2,5-C4H2SR (Cp* = 1,2,3,4,5-pentamethylcyclopentadienyl; dppe = 1,2-bis(diphenylphosphino)ethane; 2a, R = CCH; 2b, R = CCSi(CH3)3; 2c, R = CCSi(CH(CH3)2)3; 3a, R = CC2,5-C4H2SCCH; 3c, R = CC2,5-C4H2SCCSi(CH(CH3)2)3) is described. The 13C NMR and FTIR spectroscopic data indicate that the π-back donation from the metal to the carbon rich ligand increases with the size of the organic π-electron systems. The new complexes were also analyzed by CV and the chemical oxidation of 2a and 3c was carried out using 1 equiv of [Cp2Fe][PF6]. The corresponding complexes 2a[PF6] and 3c[PF6] are thermally stable, but 2a[PF6] was too reactive to be isolated as a pure compound. The spectroscopic data revealed that the coordination of large organic π-electron systems to the iron nucleus produces only a weak increase of the carbon character of the SOMO for these new organoiron(III) derivatives.  相似文献   

3.
Copper-mediated cross-coupling reactions of the 12-vertex and 10-vertex para carboranes, 1,12-C2B10H12 and 1,10-C2B8H10, with trans-1-iodo-2-chloroethene gave the bis(trans-2-chloroethenyl) carboranes, 1,12-(ClCHCH)2-1,12-C2B10H10 and 1,10-(ClCHCH)2-1,10-C2B8H8, respectively, in good yield. The molecular structures of both compounds were determined by X-ray crystallography, verifying the trans disposition of the chloride and carboranyl substituents across the double bonds. These vinyl carboranes can be converted to bis(ethynyl) carboranes, 1,12-(RCC)2-1,12-C2B10H10 and 1,10-(RCC)2-1,10-C2B8H8 (R = H or Me3Si), easily, and in high yields. These findings provide the most convenient routes to bis(ethynyl) carboranes from the commercially available carboranes, 1,12-C2B10H12 and 1,10-C2B8H10 reported to date.  相似文献   

4.
In the thermolysis of the silaterazolines silatetrazoline tBu2SiNSiCltBu2 · tBu3SiN3 the silanimine tBu2SiNSiCltBu2 and the silyl azide tBu3SiN3 are formed quantitatively. The silanimine tBu2SiNSiCltBu2 has been trapped with Et3NHF, Me3NHCl, water, 1-butene, 2,3-dimethyl-1,3-butadiene, isobutene, methylvinyl ether, and tBu2SiClN3. The structure of the disiloxane (tBu2SiCl-NH-SitBu2)2O and of the bis(di-tert-butylchlorsilyl)-substituted silatetrazoline tBu2SiNSiCltBu2 · tBu2SiClN3 has been determined by X-ray structure analysis.  相似文献   

5.
The review describes a class of versatile bidentate phosphines having a homochiral 1,2-disubstituted cyclopentane backbone, the use of such ligands in coordination chemistry, and their application in transition metal-catalyzed synthesis, including CH activation, CC coupling, CC hydrogenation, and hydroformylation. In particular, the synthetic potential of the multi-purpose PH and PCl reagents (R,R)- and (S,S)-C5H8(PX2)2 (X = H, Cl) is highlighted, since these open up the possibility to incorporate virtually any other PO-, PN- or PC-bonded residue (“module”) into the homochiral bis(phosphine) framework. The resulting chelate ligands allow access to transition metal catalysts with stereodiscriminating properties determined by parameters such as (i) the presence of P-substituents that are equal or pairwise different in steric demand, (ii) the spatial orientation of such substituents with respect to the coordination plane of the catalyst complex, and (iii) the combination of C- and P-chirogenic stereoelements in matched (or mismatched) fashion. A comparative discussion of the crystal structures that are currently available for the free ligands and their transition metal complexes is also presented.  相似文献   

6.
The reaction of VOF3 with (C2H5)4NF, (CH3)4NCl and (C4H9)4NBr salts in anhydrous CH3CN produced new complexes with the anion general formula [VOF3X] in that (X = F, Cl, Br). These were characterized by elemental analysis, IR, UV/Visible and 19F NMR spectroscopy. The optimized geometries and frequencies of the stationary point are calculated at the B3LYP/6-311G level of theory. Theoretical results showed that the VX (X = F, Cl, Br) bond length values for the [VOF3X] in compounds 1-3 are 1.8247, 2.4031 and 2.5595 Å, respectively. Also, the VF5 bond length values in [VOF3X] are 1.824, 1.812 and 1.802 Å, respectively. These results reveal that the bond order for VX bonds decrease from compounds 1 to 3, while for VF5 bonds, the bond orders increase. It can be concluded that the decrease of VX bonds lengths and the increase of VF5 bond lengths in compounds 1-3 result from the increase of the hyperconjugation from compounds 1 to 3. Harmonic vibrational frequencies and infrared intensities for VOF4, VOF3Cl and VOF3Br are studied by means of theoretical and experimental methods. The calculated frequencies are in reasonable agreement with the experiment values. These data can be used in models of phosphoryl transfer enzymes because vanadate can often bind to phosphoryl transfer enzymes to form a trigonal-bipyramidal structure at the active site.  相似文献   

7.
A series of heterobinuclear ferrocene-ruthenium complexes Fc(CHCH)nRuCl(CO)(PMe3)3 (n = 1, 3; n = 2, 12), Fc(CHCH)RuCl(CO)(Py)(PPh3)2 (4), and trimetallic Fc(CHCH)RuCl(CO)(PPh3)2(Py-E-(CHCH)Fc) (6) have been prepared. The length of the molecular rods is extended by successive insertion of CHCH spacers in the bridging ligands or the ancillary ligands. The respective products have been fully characterized and the structures of 3 and 12 have been established by X-ray crystallography. Electrochemical studies have revealed that ethenyl heterobimetallic complexes display two successive one-electron processes, and that intermetallic electronic communication between the two endgroups is attenuated with the increase of the length of the conjugated bridge. The electrochemical behavior of the trimetallic complex reveals strong electronic communication between ruthenium and ferrocene transmitted through the ethenyl bridge, however, it also reveals a very weak interaction between ruthenium and ferrocene transmitted through the (E)-CHCH-Py bridge.  相似文献   

8.
The Raman spectra of neat (C2H5)2CO (pentanone) and its binary mixtures with hydrogen donor solvent (CH3OH), [(C2H5)2CO + CH3OH] having different mole fractions of the reference system, (C2H5)2CO in the range 0.1-0.9 at a regular interval of 0.1 were recorded in the CO stretching region. In neat liquid, the Raman peak appears asymmetric. The asymmetric nature of the peak has been attributed to the CO stretching mode of the two conformers of (C2H5)2CO having C2 and C2v point groups and the corresponding bands at ∼1711 and ∼1718 cm−1, respectively. A careful analysis of the Iiso (isotropic component of the Raman scattered intensity) at different concentrations reveals that upon dilution with methanol, at mole fraction C = 0.6, an additional peak in the CO stretching region is observed at ∼1703 cm−1 which is attributed to the hydrogen bonding with methanol. A peculiar feature in this study is that upon dilution, the peak at ∼1718 cm−1 shows a minimum at C = 0.6, but on further dilution it shows a blue shift. However, the other peak at ∼1711 cm−1 shows a continuous red shift with dilution as well as a maximum at C = 0.7 in the linewidth vs. concentration plot, which is essentially due to competition between motional narrowing and diffusion phenomena. A significant amount of narrowing in the Raman band at ∼1718 cm−1 can be understood in terms of caging effect of the reference molecule by the solvent molecules at high dilution. A density functional theoretic (DFT) calculation on optimized geometries and vibrational frequencies of two conformers of neat (C2H5)2CO in C2 ad C2v forms and the complexes with one and two CH3OH molecules with both the conformers was performed. The experimental results and theoretical calculations together indicate a co-existence of two conformers as well as hydrogen bonded complex with methanol in the binary mixture, [(C2H5)2CO + CH3OH] at intermediate concentrations.  相似文献   

9.
The first luminescent rhenium(I)-gold(I) hetero organometallics, Re{phenAu(PPh3)}(CO)3Cl (3) and Re{(PPh3)AuphenAu(PPh3)}(CO)3Cl (4), have been prepared using the gold(I) complex AuCl(PPh3) (PPh3 = triphenylphosphine) and the novel rhenium(I) complexes Re(phenH)(CO)3Cl (5) (phenH = 3-ethynyl-1,10-phenanthroline) or Re(HphenH)(CO)3Cl (6) (HphenH = 3,8-bis(ethynyl)-1,10-phenanthroline). All the present rhenium(I) complexes 3-6 were revealed to possess a facial configuration (fac-isomer) with respect to the three carbonyl ligands. The main frameworks for these new gold(I) organometallics were constructed by the Au-C σ-bonding (with the η1-type coordination) between the ethynylphenanthrolines and the Au(I) phosphine unit. Re(I)-Au(I) heterometallics 3 and 4 have shown single phosphorescence from the 3MLCT excited state and this observation can be interpreted in terms of the efficient intramolecular energy transfer from the Au(I) unit to the Re(I) unit.  相似文献   

10.
11.
Trans-di(ortho-tolylethynyl)bis(dimethylphenylphosphine)palladium(II) reacts above −20 °C with the iodonium reagent IPhCl2 to give predominantly o-Tol-CC-Cl, above 15 °C with IPh2(OTf) (OTf = triflate) to give o-Tol-CC-Ph and (o-Tol-CC)2 in ca. 3:1 ratio, and above 10 °C with IPh(CCR)(OTf) (R = But, SiMe3) to give predominantly o-Tol-CC-CC-R and (o-Tol-CC)2. 31P NMR spectra provide evidence for detection of intermediates. The complexes trans-[Pd(CC-o-Tol)2(PMe2Ph)2] and trans-[PdCl(CC-o-Tol)(PMe2Ph)2] are obtained on reaction of trans-[PdCl2(PMe2Ph)2] with Li(CC-o-Tol) and o-Tol-CCH/Et3N, respectively, and have been characterised by X-ray crystallography.  相似文献   

12.
Complexes M(CCCSiMe3)(CO)2Tp′ (Tp′ = Tp [HB(pz)3], M = Mo 2, W 4; Tp′ = Tp [HB(dmpz)3], M = Mo 3) are obtained from M(CCCSiMe3)(O2CCF3)(CO)2(tmeda) (1) and K[Tp′].Reactions of 2 or 4 with AuCl(PPh3)/K2CO3 in MeOH afforded M{CCCAu(PPh3)}(CO)2Tp′ (M = Mo 5, W 6) containing C3 chains linking the Group 6 metal and gold centres.In turn, the gold complexes react with Co33-CBr)(μ-dppm)(CO)7 to give the C4-bridged {Tp(OC)2M}CCCC{Co3(μ-dppm)(CO)7} (M = Mo 7, W 8), while Mo(CBr)(CO)2Tp and Co33-C(CC)2Au(PPh3)}(μ-dppm)(CO)7 give {Tp(OC)2Mo}C(CC)2C{Co3(μ-dppm)(CO)7} (9) via a phosphine-gold(I) halide elimination reaction. The C3 complexes Tp′(OC)2MCCCRu(dppe)Cp (Tp′ = Tp, M = Mo 10, W 11; Tp′ = Tp, M = Mo 12) were obtained from 2-4 and RuCl(dppe)Cp via KF-induced metalla-desilylation reactions. Reactions between Mo(CBr)(CO)2Tp and Ru{(CC)nAu(PPh3)}(dppe)Cp (n = 2, 3) afforded {Tp(OC)2Mo}C(CC)n{Ru(dppe)Cp} (n = 2 13, 3 14), containing C5 and C7 chains, respectively. Single-crystal X-ray structure determinations of 1, 2, 7, 8, 9 and 12 are reported.  相似文献   

13.
The reaction of electrophilic reagents such as halogens, nitric and sulfuric acids, and sulfur dioxide with nanosized stereoregular polyacetylene was studied. Polymers with chlorine content as much as 65% were obtained and the MW properties of the polymers were found to depend on the structure of pristine polyacetylene prepared under various conditions. The reaction between nitric acid and stereoregular polyacetylene occurred to give first [CH(NO2)CHCHCH(OH)]n while the totally nitrated product [CH(NO2)CH(ONO2)]n was obtained with nitrogen content of 18.3% after complete nitration. GPC, NMR- and IR-spectroscopy were used for structural and MWD analysis of the original polyacetylene and obtained products. The mechanism of the reaction between electrophilic reagents and polyacetylene is discussed on the basis of the experimental and literature data.  相似文献   

14.
Within the framework of polarizable continuum model with integral equation formalism (IEF-PCM), an argon matrix effect on the geometry and infrared frequencies of the agostic H2CMH2 (M = Ti, Zr, Hf) methylidene complexes was investigated at B3LYP level of theory with the 6-311++G(3df,3pd) basis set for C, H, and Ti atoms and Stuttgart/Dresden ECPs MWB28 and MWB60 for the Zr and Hf atoms. At the B3LYP/IEF-PCM level of theory, H2CTiH2 was optimized to an energy minimum having a pyramidal structure. The calculated dipole moment of this structure is 3.06 D. The B3LYP/IEF-PCM simulations gave the three complexes’ agostic angle ∠HCM (°), distance r(H?M) (Å), and CM bond length r(CM) (Å) as follows: ∠HCTi = 87.4, r(H?Ti) = 2.079, r(CTi) = 1.803; ∠HCZr = 89.3, r(H?Zr) = 2.243, r(CZr) = 1.956; ∠HCHf = 94.7, r(H?Hf) = 2.343, r(CHf) = 1.972. As a comparison, the B3LYP simulations gave the values as follows: ∠HCTi = 91.5, r(H?Ti) = 2.150, r(CTi) = 1.811; ∠HCZr = 92.9, r(H?Zr) = 2.299, r(CZr) = 1.955; ∠HCHf = 95.6, r(H?Hf) = 2.352, r(CHf) = 1.967. As far as the MH2 symmetric and asymmetric stretching and CH2 wagging frequencies are concerned, the IEF-PCM calculated values are in better agreement with the experimental argon matrix ones than those calculated based on a gas phase model.  相似文献   

15.
The cationic aniline complex [CpRh(η6-2,6-(Me2CH)2C6H3NH2)](OTf)2 (1) was prepared from either [CpRh(η2-NO3)(η1-OTf)] or [CpRh(OH2)3](OTf)2 and 2,6-diisopropylaniline. Complex 1 underwent substitution with phosphines or phosphites, indicating the labile character of the η6-aniline ligand. Complex 1 mediated cycloaddition reactions of several alkynes in refluxing ethanol: the [2 + 2] dimerization for PhCCPh and the [2 + 2 + 1] trimerization for PhCCH and CH3C6H4CCH. The unexpected cyclobutadiene complex [CpRh(η4-C4(C(O)CH3)2H(SiMe3))] was obtained from complex 1 and Me3SiCCCCSiMe3 and structurally characterized by X-ray diffraction.  相似文献   

16.
Bimetallic alkylidene complexes of tungsten (R′O)2(ArN)WCH-SiR2-CHW(NAr)(OR′)2 (R = Me (1), Ph (2)) and (R′O)2(ArN)WCH-SiMe2SiMe2-CHW(NAr)(OR′)2 (3) (Ar = ; R′ = CMe2CF3) have been prepared by the reactions of divinyl silicon reagents R2Si(CHCH2)2 with known alkylidene compounds R′′-CHMo(NAr)(OR′)2. (R′′ = But, PhMe2C) Complexes 1-3 were structurally characterized. Ring opening metathesis polymerization (ROMP) of cyclooctene using compounds 1-3 as initiators led to the formation of high molecular weight polyoctenamers with predominant trans-units content in the case of 1 and 3 and predominant cis-units content in the case of 2.  相似文献   

17.
18.
Novel fluorinated silane coupling agents with a biphenyl structure, CnF2n+1(C6H4)2CH2CH2Si(OCH3)3 (n = 4, 6, and 8), were synthesized with the aim to improve the heat-resistance, oxidation-resistance, and acid-resistance of the surface modified with a common fluorinated silane coupling agent. Alcohols, Rf(C6H4)2CH(OH)CH3, were obtained by reducing the intermediates, Rf(C6H4)2COCH3, the products of the reaction of 4-acetyl-4′-bromobiphenyl with perfluoroalkyl iodides in the presence of copper powder. The reaction of the alcohols with phosphorus tribromide gave olefins, Rf(C6H4)2CHCH2, which were then allowed to react with tetramethoxysilane in the presence of hexachloroplatinate(IV) catalyst to yield novel fluorinated silane coupling agents with a biphenyl structure. The coupling agents with four and six carbon atoms in their fluorocarbon chains were obtained as a colorless liquid while that with 8 carbon atoms was a white gel. Evaluations were made of the coupling agents using surfaces modified with them in terms of water contact angles, heat-resistance, oxidation-resistance, and acid-resistance. The agents behaved similarly to the conventional fluorinated silane coupling agents with respect to water contact angles, oxidation-resistance, and acid-resistance, whereas the former showed an extremely higher heat-resistance (up to 350 °C). In addition, C6H5C6H4CH2CH2Si(OCH3)3 and CH3(C6H4)2CH2CH2Si(OCH3)3 with no fluoroalkyl group were synthesized and the heat-resistance of glass surfaces modified with these compounds was examined.  相似文献   

19.
Mismatched molecular 1:1 complexes of C10F8 with catenated chalcogen-nitrogen compounds C6H5-X-NSN-SiMe3 (X = S, Se) were prepared and characterized by X-ray crystallography. The complexes provide examples of structurally non-rigid polyheteroatom molecules involved in non-covalent arene-polyfluoroarene π-stacking interactions. In going from homocrystals to the co-crystals, the molecular Z, E configuration of the catenated compounds changes from noticeably non-planar to perfectly planar, i.e. C10F8 acts as “molecular iron”. On the other hand, C10H8 does not produce complexes with C6F5-X-NSN-SiMe3 (X = S, Se).  相似文献   

20.
Treatment of RuHCl(CO)(PPh3)3 with (3E,5E,7E,9E,11E)-HCC-(CHCH)5- CCH produces [RuCl(CO)(PPh3)2]2[μ-(CHCH)7]. The later complex reacts with PMe3 to give [RuCl(CO)(PMe3)3]2[μ-(CHCH)7], the structure of which has been confirmed by X-ray diffraction. The through-space distance from one Ru to the other is 19.88 Å.  相似文献   

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