离子液体作为溶剂/催化剂用于卤代烃对胺的选择性烷基化反应

在三乙胺存在下,在离子液体([bmim]I和[bmim]PF6)中进行了各种卤代烃对胺类化合物中氨基的选择性烷基化反应.反应在相对温和的条件下进行,转化率和选择性优异.离子液体可以回收并重复使用.     

Chemistry of iron complexes. Part V. Electron spin resonance spectra of some iron(III) complexes and X-Ray diffraction (powder) data of iron(II) complexes employing tertiary phosphine/arsine oxides

Summary Electron spin resonance spectra (X-band, 9.3 GHz) of iron(III) chloride complexes with tri-p-tolylarsine oxide (T₃AO), methylenebis(diphenylphosphine oxide) (mdpo) and 1,4-tetramethylenebis(diphenylphosphine oxide) (tmdpo) support their structures as [Fe(L-L)₂Cl₂][FeCl₄] (L-L=mdpo or tmdpo) and [Fe(T₃AO)₂Cl₂(OH₂)₂][FeCl₄]2H₂O. The x-ray powder diffraction patterns of some iron(II) iodide complexes with mdpo, tmdpo, dmdpo, dmdao and tmdao [dmdpo-1,2-dimethylenebis(diphenylphosphine oxide); dmdao and tmdao are the arsine analogs of dmdpo and tmdpo] show that the complexes are crystalline but not isomorphous.     

Imidazolium Based Probes for Recognition of Biologically and Medically Relevant Anions

The imidazolium derivatives due to their positive charge possess one of the most polarized and positively charged proton at C2‐H to form strong ionic hydrogen bond (also termed as double ionic hydrogen bond) with anions and also provide opportunities for anion – π interactions with electron‐deficient imidazolium ring. In the present review article, imidazolium based molecular probes for their ability to recognize inorganic anions like halides, cyanide, perchlorate, carboxylic acids, phosphate, sulfate etc. and their derived molecules viz. nucleotides, DNA, RNA, surfactants, proteins, etc have been discussed. The review covers the literature published after year 2009 and has > 130 references. The previous literature has already been discussed by Yoon et al. in two review articles published in Chem. Soc. Rev. 2006 and 2010.     

Scattering and absorption differential cross sections for double photon Compton scattering

The scattering and absorption differential cross sections for nonlinear QED process such as double photon Compton scattering have been measured as a function of independent final photon energy. The incident gamma photons are of 0.662 MeV in energy as produced by an 8 Ci¹³⁷Cs radioactive source and thin aluminum foils are used as scatterer. The two simultaneously emitted photons in this process are detected in coincidence using two Nal(T1) scintillation detectors and a slow-fast coincidence set-up of 30 nsec resolving time. The measured values of scattering and absorption differential cross sections agree with theory within experimental estimated error.     

Reaction of 2-phenyl-4-methyl-Δ2-oxazolin-5-one with imines. A convenient synthesis of 3-amido-β-lactams

Azlactone 3a reacted with furan-2-aldehyde and thiophene-2-aldehyde imines to give corresponding 3-amido-β-lactams in good yields.     

Model for predicting the composition of copolyesters: Polymerization of terephthalic acid, 2,2′-oxydiethanol,and 2,2-dimethyl-1,3-propanediol

Copolyesters of two glycols and a dicarboxylic acid moiety are frequently made to obtain specific physical properties. In the synthesis of these polymers an excess of glycol is used in the ester-exchange reaction and then removed during the polycondensation reaction to form a high-molecular-weight product. A model has been developed to predict the final polymer composition. The derivation is based on equilibria of reaction species (free glycol, polymer chain ends, and ester links) and the relative vapor pressures of the two reacting glycols. Calculated results are compared with experimental results of poly(2,2′-oxydiethylene: 2,2-dimethyl-1,3-propylene terephthalate)s. There is good agreement between calculated and experimental compositions. The model can be used to calculate the glycol concentrations that must be used to make a specific polymer composition. This model should also be useful in the calculation of other mole ratios of glycol to dicarboxylic acid that will make the same composition.     

Picosecond transient absorption spectra and kinetics of salicylidenaniline

Using the picosecond time-resolved absorption spectroscopic technique, the transient absorption spectra of salicylidenamline have been investigated and the room-temperature kinetic data are presented. A possible mechanism of the formation of the photochromic products of salicylidenamlme is proposed.     

Ligating properties of tertiary phosphine/arsine sulphides or selenides—VI. Addition compounds of zinc(II), cadmium(II) and mercury(II) with sulphides or selenides of triphenyl- and tri- -tolylphosphines and 1,3-trimethylenebis (diphenylphosphine)

Post-transition elements react with ligands, triphenylphosphine sulphide or selenide (Ph₃PS or Ph₃PSe), tri-p-tolylphosphine sulphide or selenide (T₃PS or T₃PSe) and 1,3-trimethylenebis-(diphenylphosphine sulphide or selenide) (PDPS or PDPSe) in suitable organic solvents forming complexes of compositions: MX₂. L(M = Zn, X = I, L = all except Ph₃PS: M = Cd, X = I, L = T₃PS, T₃PSe, M = Hg, L = T₃PSe, X = Cl, Br, I); ZnI₂·2Ph₃PS, Hg(NO₃)₂·2Ph₃PS, CdBr₂·3T₃PSe and 3Hg(NO₃)₂·4Ph₃PSe. All these have been characterized through elemental analyses, ir spectra (4000−200 cm⁻¹) and molar conductance (nitrobenzene). Complexes are essentially nonelectrolytes. Tetrahedral structures have been assigned to all except a 1 : 3 complex which has been assigned a bridged octahedral structure.     

Thiopegan derivatives—XXI A mechanism for the formation of 9:10 and 10:11 thiopegan derivatives

Reactions between -haloketones and o-carbethoxy phenyl thiourea have been discussed; a mechanism for the observed exclusive formation of 9:10-thiopega-2:10-diene-4-ones in the case of -haloalkaryl ketones has been advanced and a number of intermediates isolated in case of chloro acetone.     

Interaction of photons with some solutions

The linear attenuation coefficients in aqueous solutions of some chlorides and sulphates, viz. MgCl₂·6H₂O, CaCl₂, SrCl₂·6H₂O, BaCl₂·2H₂O, Na₂SO₄, K₂SO₄ and MgSO₄·7H₂O were determined at 81, 356, 511, 662, 1173 and 1332 keV by the γ-ray transmission method in a good geometry setup. From the precision measured densities of these solutions, mass attenuation coefficients were then obtained which varied systematically with the corresponding changes in the concentrations (g/cm³) of these solutions. A comparison between experimental and theoretical values of attenuation coefficients has shown that the study has potential application for the determination of attenuation coefficients of solid solutes from their solutions without obtaining them in pure crystalline form.