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1.
The reactions of the Me n C6H6−n M(CO)3 (M=Cr, Mo, W;n=3, 5, 6) and C5R5M(CO)3 (M=Mn, Re; R=H, Me) complexes with propargyl alcohol in acidic media under UV irradiation were studied. Novel Me n C6H6−n M(CO)23-C3H3)BF4 (M=Mo, W;n=3, 5, 6) and C5R5Re(CO)23-C3H3)CF3SO3 complexes with the 3ē-propargyl ligand were synthesized, and their properties compared with those of similar η3-allyl derivatives. The structure and dynamic propeties of the compounds obtained are discussed. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1796–1803, September, 1999.  相似文献   

2.
The molecular structure of the previously reported compound [Mo(CO)3(η6-P3C3But3)] has been determined by a single-crystal X-ray diffraction study. Syntheses and molecular structures are also described for the structurally related compounds [Mo(CO)3(η5-P3C3But3)(Me)(Bun)], [Mo(CO)3(η5-P3C3But3)(H)(Bun)] and [Mo(CO)3(η4-P3C3But3(Me)(Bun)(H)(O)Li(THF)3]. Density functional calculations at the B3LYP/cc-pVDZ(-PP) and BP86/cc-pVDZ(-PP) levels have been carried out on the above complexes and the nature of the bonding between the different rings and molybdenum is discussed. 31P NMR spectroscopic evidence is presented for the existence of the novel complex [Mo(CO)3(η6-P3C3But3)PtCl2(PEt3)] in which the triphosphabenzene ring acts as an overall 8-electron donor to the two metal centres.  相似文献   

3.
11NTRODUCT1ONWeattemptedtosynthesizeanextractant(1)bythereactionofadipylchloridewithcyclopentanonepiperidineenamineaccordingtoHunig'sprocedure"',however,wemainlyobtainedthetitlecompound,whichmaybepossiblyapotentialmedicinet2'3i.Itsmolecularstructurewasfinallyconfirmedbythesingle-crystalstructuredeterminationafterconventionalUV,IR,lHNMR,MSandelementana-lyticalworks.2EXPER1MENTALSECT1ON2.1SynthesisToastirredsolutioncontaining8Omlofchloroform,2.8mloftri-ethylamineand1.51g(O-Olmol)…  相似文献   

4.
The reactions of terpene nitrosochlorides derived from 3-carene, ??-pinene, and limonene, with simplest azaheterocycles (imidazole, benzotriazole, and indole) were studied. On the base of these transformations, preparative procedures to access chiral oximes bearing azaheterocyclic moieties in the ??-position to the oxime fragment, namely, ??-(1H-imidazol-1-yl)-, ??-(1H-benzo-[d][1,2,3]triazol-1-yl)-, and ??-(1H-indol-3-yl)-substituted terpenic oximes, were developed. Transformations of the studied monoterpene nitrosochlorides into ??-substituted oximes proceeded stereoselectively to give in the moderate yields (30?C60%) the only stereoisomer arising from the attack of the heterocyclic anion from the less hindered side of the intermediate nitroso olefin generated in situ from nitrosochloride.  相似文献   

5.
The reaction of 4-(2R-1-chloro-2-oxoethylidene)-substituted imidazolidine-1-oxyl with sodium azide gives monoimines of -diketones, derivatives of 3-imidazoline nitroxides. Reactions of these products with nitrogen binucleophiles were used to prepare various heterocyclic compounds containing an imidazoline nitroxide moiety.  相似文献   

6.
7.
Wenhua Huang  Jingyi Li  Lihua Ou 《合成通讯》2013,43(13):2137-2143
Isoquinoline, β‐carbolines, and 3‐deazapurines were prepared in 52–81% yields via oxidative decarboxylation of cyclic α‐amino acids using ammonium persulfate as an oxidant in the presence of catalytic silver.  相似文献   

8.
Diuridine 3', 5'-boianophosphate has been synthesized. Its diastereomers were separated and their configurations were tentatively assigned based on the selective snake venom phosphodiesterase (SVPDE) hydrolysis. It is found that, compared to the unmodified parent compound diuridine phosphate, the nucleophilicity and the stability of the modified compounds to SVPDE are significantly enhanced.  相似文献   

9.
Recent studies towards understanding the molecular mechanisms of apoptosis have revealed the importance of a group of cysteinyl aspartate specific proteases, the caspases, in the programmed cell death process (Hengartner, M.O. Nature 2000, 407, 770). Caspase-3, in particular, has been characterized as the dominant effector caspase involved in the proteolytic cleavage of a variety of protein substrates including cytoskeletal proteins, kinases and DNA repair enzymes during apoptosis (Nicholson…  相似文献   

10.
Hydrogen- and lithium-bonded complexes of A-H∕Li (A = F, Cl) with the amine analogues NF(3), NH(3), and NH(2)(CH(3)) were studied at the MP2∕6-311++G(d,p) level of theory. Bond extensions and redshifts were obtained for the H-bonded complexes, while bond extensions and blueshifts were obtained for the Li-bonded species. The variation of these and other properties with the basicity of the amines was investigated and rationalized by comparing the ab initio results with predictions from a model derived from perturbation theory.  相似文献   

11.
Quantum chemical calculations using gradient-corrected density functional theory (B3LYP) and ab initio methods at the MP2 level are reported for the geometries and bond energies of the nitrido complexes Cl2 (PH3)3ReN–X (X = BH3, BCl3, BBr3, AlH3, AlCl3, AlBr3, GaH3, GaCl3, GaBr3, O, S, Se, Te). The theoretical geometries are in excellent agreement with experimental values of related complexes which have larger phosphine ligands. The parent nitrido complex Cl2(PH3)3ReN is a very strong Lewis base. The calculated bond dissociation energy of Cl2(PH3)3ReN–AlCl3 is D e = 43.7 kcal/mol, which is nearly as high as the bond energy of Me3N–AlCl3. The donor-acceptor bonds of the other Cl2(PH3)3ReN–AY3 complexes are also very strong. Even stronger N–X bonds are predicted for most of the nitrido-chalcogen complexes, which exhibit the trend X = O ≫ S > Se > Te. Analysis of the electronic structure shows that the parent compound Cl2(PH3)3ReN has a Re–N triple bond. The Re–N σ bond is clearly polarized towards nitrogen, while the two π bonds are nearly nonpolar. The Re–N σ and π bonds become more polarized toward nitrogen when a Lewis acid or a chalcogen atom is attached. Bonding in AY3 complexes should be described as Cl2(PH3)3ReE≡N→AY3, while the chalcogen complexes should be written with double bonds Cl2(PH3)3Re=N=X. The charge-decomposition analysis indicates that the nitrogen-chalcogen bonds of the heavier chalcogen complexes with X = S, Se, Te can also be interpreted as donor-acceptor bonds between the nitrido complex acting as a Lewis base and the chalcogen atom with an empty p(σ) orbital acting as a Lewis acid. The nitrido oxo complex Cl2(PH3)3 Re=N=O has a covalent N–O double bond. Received: 27 July 1998 / Accepted: 26 October 1998 / Published online: 16 March 1999  相似文献   

12.
Oxygenated volatile organic compounds (OVOCs) influence the oxidative properties of the atmosphere, and their transport from the ground may occur by scavenging by the HNO(3)-rich supercooled water droplets found in polluted convective air masses. With infrared spectroscopy, we have studied the interactions of four typical atmospheric OVOCs (acetone, hydroxyacetone, acetaldehyde and benzaldehyde) with model surfaces of water ice and of trihydrated nitric acid (NAT) ice. We show that these molecules weakly adsorb on water ice and NAT by hydrogen bonding. No chemical reaction occurs between the molecules and the NAT substrate, the OVOCs remaining intact when in contact with hydrated HNO(3) in atmospheric ice clouds.  相似文献   

13.
14.
《Fluid Phase Equilibria》1999,164(1):97-106
Near-saturation pressure, density, and temperature (P,ρ,T) and vapor-pressure measurements for NH3 are reported over a temperature range from 279 to 392 K. Liquid-phase isothermal (P,ρ,T) and bubble-point-pressure measurements for two standard mixtures of NH3+H2O (xNH3=0.8360 and 0.9057 mole fraction) are reported over a temperature range from 280 to 379 K and at pressures to 7.7 MPa. These data are compared to literature data and correlations and agree within ±3% for bubble-point pressures, ±0.005 g/cm3 for liquid densities, and ±0.0011 g/cm3 for vapor densities. A consistent data set for equation-of-state optimization at high concentrations of NH3 is proposed.  相似文献   

15.
New esters of 3β,5α,6β-trihydroxysteroids and 3β,5-dihydroxy-6-ketosteroids containing 6-chloropyridine groups characteristic of the alkaloid epibatidine were synthesized by acylation with 6-chloronicotinoylchloride. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 175-179, March-April, 2009.  相似文献   

16.
n-In_2S_3 has been prepared by CVT method.The photoelectrochemical behavior of n-In_2S_3 in a polysulfide redox solution was investigated.It was found that photoetching remarkablyincreased the fill factor.The maximum quantum efficiency of carrier collection reached 95% after 12hirradiation at 100 mW/cm~2 at an applied potential of+1.2V.XPS and Auger analysis were carriedout for examining surface and bulk concentration.The photoetching effect could be satisfactorilyexplained.  相似文献   

17.
Gorokhovik I  Neuville L  Zhu J 《Organic letters》2011,13(20):5536-5539
Ketoanilides containing alkyl side chains were readily cyclized to 3-hydroxy-2-oxindoles or spirooxindoles by a single or double intramolecular Friedel-Crafts reaction in the presence of trifluoroacetic acid (TFA) at room temperature or at 45 °C. α-Iminocarboxamides, generated in situ from ketoamides, cyclized similarly to 3-aminooxindoles under identical conditions.  相似文献   

18.
The Raman spectra of the carbon—chlorine symmetric stretching mode, ν4, of the Group IVA methylmetal trichlorides (CH3MCl3, M  C, Si, Ge, Sn) were acquired in a number of solvents of varying molecular properties. Non-linear curve fitting procedures were used to separate the four band components resulting from chlorine isotope splitting.The band maxima of the two lighter members of the series were observed to shift to lower frequency with increasing solvent polarizability, indicating the predominance of solute—solvent dispersion forces. In the germanium and tin compounds, on the other hand, the peak frequencies were correlated, instead, with solvent dipole moment. This result is in contrast to earlier studies on the ν1 (CH3 symmetric stretching) vibration, for which dispersion interactions are the dominant frequency displacement mechanism in all four compounds.The bandwidths of the ν4 vibration were found to depend on dipolar interactions in the germanium and tin compounds. However, this correlation was not observed for the two lighter series members, nor for the carbon—chlorine antisymmetric stretching vibration in CH3SnCl3.  相似文献   

19.
Synthesis and structure of a supramolecular dimer and inorganic–organic cocrystal of composition [{CuIIL1?(H2O)}2(C8H6O4)] (1) are described (H2L1= N,N′-ethylenebis(3-ethoxysalicylaldimine); C8H6O4 = terephthalic acid). Crystal engineering has been utilized for the designed synthesis of the title compound. Compound 1 crystallizes in a triclinic system with P 1 space group. The structure consists of terephthalic acid and two symmetry related inclusion products [CuIIL1?(H2O)], in which the water molecule is encapsulated in the O4 compartment by forming bifurcated hydrogen bonds involving two hydrogen of water and phenolate and ethoxy oxygens of the compartmental ligand. Hydrogen bonding between encapsulated water molecules and terephthalic acid forms the supramolecular dimer. The title compound is an example of an inorganic–organic cocrystal as well. Weak interactions, such as semicoordination of phenoxo oxygen of one unit to the metal center of a symmetry related unit and C–H ··· O, and O–H ··· O hydrogen bonds result in generation of an overall 3-D topology in the title compound. The 3-D topology can be understood as interlinking of two different 2-D sheets.  相似文献   

20.
Reaction of [Ln(CH(2)SiMe(3))(2)(THF)(n)][BPh(4)] (Ln = Sc, Y, Lu ; n = 3, 4) with Li{B(NArCH)(2)}(THF)(2) (Ar = 2,6-C(6)H(3)(i)Pr(2)) formed the first group 3 and lanthanide boryl compounds, Sc{B(NArCH)(2)}(CH(2)SiMe(3))(2)(THF) and Ln{B(NArCH)(2)}(CH(2)SiMe(3))(2)(THF)(2) (Ln = Y, Lu), which contain two-center, two-electron Ln-B σ bonds. All of these systems were crystallographically characterized. Density functional theory analysis of the Ln-B bonding found it to be predominantly ionic, with covalent character in the σ-bonding Ln-B HOMO.  相似文献   

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