Photochemical kinetics for holographic grating formation in phenanthrenequinone doped poly (methyl methacrylate) photopolymer

The photochemical kinetics of phenanthrenequinone (PQ) doped poly (methyl methacrylate) photopolymer in holographic recording was studied theoretically and experimentally. The diffusion of PQ molecules during holographic recording was negligible because of its small diffusion coefficient at room temperature. A photochemical reaction kinetics model of PQ/PMMA was established. The analytical expressions for the temporal variations of transmittance and diffraction efficiency were derived. By fitting the experimental curves, some parameters related with the polymer components were obtained by the proposed model, which can be used to analyze the photochemical process and will be helpful to the optimization of material preparation.     

Studies in the Imidazole Series. 100. Synthesis of Derivatives of Imidazo[1,2-a]pyrimidine from 2-Aminopyrimidines, Methyl Aryl Ketones, and Halogens

We have synthesized imidazo[1,2-a]pyrimidine derivatives by reaction of 2-aminopyrimidines with methyl aryl ketones and halogens (bromine, iodine). Using bromine leads to formation of 6-bromo- and 3,6-dibromo-substituted 2-arylimidazo[1,2-a]pyrimidines.     

Heterocyclic Systems Containing Bridged Nitrogen Atom: Synthesis and Antibacterial Activity of 3‐(2‐Phenylquinolin‐4‐yl)/3‐(1‐p‐Chlorophenyl‐5‐methyl‐1,2,3‐triazol‐4‐yl)‐s‐triazolo[3,4‐b]‐1,3,4‐thiadiazine Derivatives

The condensation of 4‐amino‐5‐mercapto‐3‐(2‐phenylquinolin‐4‐yl)/3‐(1‐p‐chlorophenyl‐5‐methyl‐1,2,3‐triazol‐4‐yl)‐1,2,4‐triazoles 1a‐b with chloroacetaldehyde 2a‐b , ω‐bromo‐ω‐(1H‐1,2,4‐triazol‐1‐yl)acetophenone 3a‐b , chloranil 4a‐b , 2‐bromocyclohexanone 5a‐b , 2,4′‐dibromoacetophenone 6a‐b and 2‐bromo‐6′‐methoxy‐2′‐acetonaphthone 7a‐b are described. The structures of the compounds synthesized were confirmed by elemental analyses, IR, 1H NMR and mass spectra. The antibacterial activities were also evaluated.     

The Synthesis of Some Novel N-[a-(Isoflavone-7-O-)Acetyl ] Amino Acid Derivatives

A series of novel N-[(α)-(isoflavone-7-O-)acetyl] amino acid methyl esters were prepared from the efficient and regioselective alkylation of isoflavones with chloroacetyl amino acid derivatives under mild condition.     

相转移法制备Cu-Mn合成气一步法合成甲酸甲酯催化剂

采用月桂酸作表面活性剂相转移制备了Ｃｕ－Ｍｎ合成甲酸甲酯催化剂,结果发现相转移法制得的催化剂粒径比采用共沉淀法要小得多,已经达到了纳米超细粒子水平。同时,比表面积也显著增大,用于由合成气一步法合成甲酸甲酯的活性显著高于共沉淀法及浸渍法制得的催化剂。     

微波辐射下固相反应合成二苯基甲基醚

在常压下用微波辐射固相反应的方法合成了二苯基甲基醚,与用有机溶剂为介质及传统的热固相反应方法相比,其反应速率快,产率高。     

甲基丙烯酸甲酯原子转移自由基聚合等规度研究

在0～100℃温度范围内,由原子转移自由基聚合方法,采用助催化和非助催化体系,引发甲基丙烯酸甲酯聚合,利用¹³CNMR测定聚甲基丙烯酸甲酯的等规度.发现原子转移自由基聚合仍以间同立构为主,随着聚合温度的升高间同立构等规度降低,与通常自由基聚合对有规立构控制特征相似.助催化剂异丙醇铝和活性端羰基配位,对聚合物的立构规整性有一定的影响.     

气相色谱法分离和测定环境空气中的丙烯酸乙酯和甲基丙烯酸甲酯

用活性炭吸附环境空气中的丙烯酸乙酯和甲基丙烯酸甲酯,经二硫化碳妥吸后用气相色谱法测定在填充２．５％ＤＮＰ＋２．５％Ｂｅｎｔｏｎｅ３４／ＣｈｒｏｍｏｓｏｒｂＷ ＨＰ ＤＭＣＳ的玻璃色谱柱上,丙烯酸乙酯与甲基丙烯酸甲酯及干扰物之间能较好地分离。方法的回收率：丙烯酸乙酯为８６．４％－１０３．０％,甲基丙烯酸甲酯为８６．３％－１０１．２％,变异系数：丙烯酸乙酯为４．１％－４．４％,甲基丙烯酸甲酯为４．４％     

Synthesis and characterization of azo–bisbenzylidene‐based polymers for second order nonlinear optics

Main chain polymers containing azo and bisbenzylidene moiety were synthesized by polycondensation method. The successful polymerization reaction was characterized by UV–vis absorption, FT‐IR and NMR spectroscopy. The resulting polymers were soluble in polar solvents like dimethyl formamide (DMF) and showed good thermal stability up to 250 °C. These polymers were blended with poly methyl methacrylate (PMMA) and corona poled for characterizing second harmonic generation (SHG) property. Temperature stability study of SHG intensity of poled polymer showed that it is stable up to 80 °C. To improve temperature stability further the crosslinking of polymer under UV light is proposed. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 4317–4324     

Synthesis and structural studies of a bis(carbamoyl methyl) sulfoxide complex of uranyl nitrate

A new tri-functional ligand ⁱBu₂NCOCH₂SOCH₂CONⁱBu₂ was prepared and characterized. The coordination chemistry of this ligand with uranyl nitrate was studied with IR, ¹H NMR, electrospray mass–spectrometry, thermogravimetry, and elemental analysis. The structure of [UO₂(NO₃)₂(ⁱBu₂NCOCH₂SOCH₂CONⁱBu₂)] was determined by single-crystal X-ray diffraction. The uranium(VI) ion is surrounded by eight oxygens in a hexagonal bipyramidal geometry. Four oxygens from two nitrates and two oxygens from the ligand form a planar hexagon. The ligand is a bidentate chelate, bonding through sulfoxo and one of the carbamoyl groups to uranyl nitrate.