A facile and efficient stereoselective synthesis of highly functionalised trisubstituted alkene derivatives of ferrocenealdehyde

The reaction of the Baylis–Hillman adduct 2 of ferrocenealdehyde with various oxygen and carbon nucleophiles in the presence of montmorillonite K10 clay catalyst furnished highly functionalised trisubstituted alkene derivatives of ferrocenealdehyde in excellent yield. Synthetic use of one of products 7 has been demonstrated with the synthesis of a 1,3-diyne ether derivative of ferrocene 16 via an Eglinton coupling reaction.     

Crown-ether styryl dyes

Styryl dyes (4a,b) containing a 15-crown-5 fragment and isomeric 2- and 4-quinolinium residues with anN-sulfopropyl substituent undergo [2+2]-autophotocycloaddition to give cyclobutane derivatives (9a,b) in acetonitrile only in the presence of Mg(ClO₄)₂ or Ca(ClO₄)₂. The stereospecificity of both pathways of photocycloaddition and its efficiency are explained by the preorganization of the supramolecular dimers derived from thetrans-isomers of the dyes when they are bound into complexes with Mg and Ca cations.For Part 14, see Ref. 1.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2225–2230, November, 1995.The work was carried out with financial support from the Russian Foundation for Basic Research (Project code 94-03-08531) and the International Science Foundation (Grants ISF, M8Q000 and N38000).     

聚酰胺6／聚醚砜共混体系的结晶与熔融行为

聚醚砜（ＰＥＳ）是一种非晶特种工程塑料，具有强度好，使用温度高等特点，但熔体粘度高，加工上有一定困难．聚酰胺６（ＰＡ６）是部分结晶的工程塑料，有很好的强度和耐磨性能．加入适量的ＰＡ６，可显著地降低ＰＥＳ的熔体粘度，且可基本保持ＰＥＳ的原有性能［１］．...     

Absorption and reaction of CO2 with 2,3-epoxypropyl phenyl ether using aliquat 336 AS catalyst

A kinetic study on the absorption and reaction of carbon dioxide with 2,3-epoxypropyl phenyl ether (phenyl glycidyl ether, PGE) in benzene solution has been carried out at room temperature in the presence of tricaprylylmethyl ammonium chloride (Aliquat 336) as catalyst. A simple method of measuring the absorbed volume of CO₂ was proposed to obtain the reaction rate constant, and it was based on the film theory accompanied by a chemical reaction. The enhancement factor (β-N_CO2/N_CO2 ^o) increased with increasing bulk concentration of PGE and Aliquat 336. The flux of CO₂ was proportional to the agitation speed.     

Three-component photopolymer based on a novel mechanism: acid-catalyzed polymerization and decoupling of crosslinks

Three-component photopolymers comprising a photoacid generator, a bifunctional vinyl ether monomer and an aqueous base-soluble polymer as matrix were developed. These photopolymers exhibit either positive- or negative-working character, depending on the prebake temperature and the concentration of the photoacid generator. When the prebake temperature is high, the photo-polymer film is made insoluble in aqueous base and organic solvents by the formation of crosslinks. However, on exposure to light, the crosslinks are decoupled by the photogenerated acid and the photopolymer layer becomes again soluble in aqueous base, resulting in a positive-working character. When the concentration of the photoacid generator is low enough, the photopolymer has a negative-working character due to the cationic polymerization of vinyl ethers. The mechanism of the photochemical reaction of the photopolymers was investigated to elucidate the complicated behavior.     

乙烯基单体正离子聚合中链增长速率常数的研究进展

碳正离子聚合中,聚合速率常数的测定方法通常包括电导法、绝热量热法、胺抑制法、止流光谱法及扩散计时法。在烷基乙烯基醚、苯乙烯及其衍生物和异丁烯等几种常见乙烯基单体的正离子聚合中,本文介绍不同测定方法得到的不同结构碳正离子(包括自由离子和离子对)的链增长速率常数(kp 和kp±)。     

Vapour–liquid equilibrium data for the 1,1,1,2 tetrafluoroethane (R134a) + dimethyl ether (DME) system at temperatures from 293.18 to 358.15 K and pressures up to about 3 MPa

Isothermal vapour–liquid equilibrium data have been measured for the binary system R134a + DME at five temperatures between 293.18 and 358.15 K, and pressures between 0.4899 and 2.9442 MPa. The peculiarity of this system is the existence of an azeotrope with a minimum pressure, which disappears at 358.15 K. The experimental method used in this work is of the static-analytic type, taking advantage of two pneumatic capillary samplers (Rolsi™, Armines’ patent) developed in the CENERG/TEP Laboratory. The data were obtained with uncertainties within ±0.02 K, ±0.0001 MPa and ±1% for molar compositions.

The isothermal P, x, y data are well represented with the Redlich and Kwong equation of state using the Mathias–Copeman alpha function and the Huron–Vidal mixing rules involving the NRTL model.     

A New Crown Compound with Multifunctional Capabilities

A new crown ether, derived from the 2,2-diphenyl-1-picrylhydrazyl free radical (DPPH) and diaza-18-crown-6 (kryptofix 22) was synthesized.The physico-chemical properties of this new compound were studied using ¹H- and ¹³C-NMR, EPR, UV-Vis, and IR spectroscopy. The compound has acid-base and redox properties, each of these involving a colour change (i.e., fromyellow to red-brown for acid-base processes, and from yellow to violet for redox processes).The transport properties of the compound were studied by means of biphasic (l/l or s/l) systems. Thus, by an acid-base process alkaline cations were transported into an organic phase, as well as arginine; by a redox process, short-lived freeradicals such as ^.C₆H₅ and ^.H were generated and observed by the EPR spin-trapping technique, using t-butyl-phenyl-nitrone (PBN) as spin-trap.     

SYNTHESIS AND CHARACTERIZATION OF SIDE CHAIN LIQUID CRYSTATALLINE POLYSILOXANES CONTAINING BENZYL ETHER LINKING UNITS

Side chain liquid crystalline polysiloxanes containing benzyl ether linkingunits were synthesized by the hydrosilylation of poly (methylhydrosiloxane) with a series of4-(4-alkoxybenzyloxy)-4'-allyloxybiphenyl monomers [4-(4-methoxybenzyloxy )-4'-allyloxy-biphenyl(M_1), 4-(4-ethoxybenzyloxy)-4'-allyloxybiphenyl (M_2), 4-(4-propoxybenzyloxy)-4'-allyloxybiphenyl (M_3), 4-(4-butoxybenzyloxy)-4'-allylox(M_4), 4-(4-pentoxy-benzyloxy)-4'-allyloxybiphenyl (M_5), 4-benzyloxy-4'-allyloxybiphenyl (M_6)]. The phasebehavior of monomeric and polymeric liquid crystals was characterized by differential scan-ning calorimetry and optical polarization microscopy where the groups are ranged frommethoxy to pentoxy Both the monomeric and polymeric liquid crystals exhibit 1iquidcrystal behaviors.     

Synthesis and Complexation Behavior Studies of Novel Bis-crown Ethers

The novel unique structures of bis-crown ethers were successfully synthesized from tri (propylene glycol) di-acrylate with amino- and aza-crown ethers through Michael addition. The crown ethers contained the primary and the secondary amine group such as 2-aminomethyl crown ethers, 4-aminobenzo crown ethers and 1-aza crown ethers. The newly synthesized bis-crown ethers were characterized by elemental analyses, IR, ¹H NMR, ¹³C NMR, mass spectrum, respectively. The newly synthesized host compounds of bis-crown ethers showed complex ability with various sizes of alkali metal cations such as Na⁺, K⁺, Rb⁺ and Cs⁺. The complexation behavior was examined by ¹H NMR spectroscopy and UV spectrometry.