CC14法合成α—羟基—α—甲基苯丙酮的研究

α 羟基 α 甲基苯丙酮 (ＰＨＭＰ)是一种性能优良的新型光引发剂 ,具有引发效率高、热稳定性好、耐黄变、无异味等优点[1,2 ] 。现有合成方法步骤多 ,产率低 ,后处理麻烦 ,操作复杂[3,4] ,且在反应过程中会产生ＨＣ1或ＨＢｒ等有毒副产物。本文研究了在相转移催化剂的作用下[5,6 ] ,ＣＣｌ4直接氯化水解生成α 羟基 α 甲基苯丙酮的新方法。该方法不仅减少了反应步骤 ,简化了操作 ,而且提高了产品质量。1　实验部分1 .1　仪器与试剂傅立叶红外光谱仪Ｐｅｒｋｉｎ Ｅｌｍｅｒ 1 71 0 ,ＷＸＳ 1型阿贝折光仪。异丁酸 ,ＳＯＣｌ2 ,苯 ,四氯化…     

Phase separation in the formation of hollow particles by suspension polymerization for divinylbenzene/toluene droplets dissolving polystyrene

Phase-separation behavior within polymerizing divinylbenzene/toluene droplet dissolving polystyrenes (PS) was investigated to clarify the formation mechanism of the hollow polymer particles by suspension polymerization. No hollow particles were obtained at a low content of low-molecular-weight PS where phase separation occurred at high conversion. On the other hand, hollow particles were obtained at a high content of high-molecular-weight PS where phase separation occurred at low conversion. The phase separation in an early stage of the polymerization, which was promoted by the presence of PS and cross-links of polydivinylbenzene, was a key factor for the formation of the hollow structure.     

2-芳基硫杂脯氨酸结构特征的研究

对12种2-芳基硫杂脯氨酸进行了红外光谱和核磁共振谱测定,对其中两个化合物作了质谱测定。结果表明,这类化合物固态时主要以两性离子形式存在;有较强的分子离子峰,是一类较稳定的化合物。它们还存在一对非对映异构体,芳环上的取代基对芳环电子云密度的影响较大,而对四氢噻唑环的影响较小。     

A heterogeneous model for gas transport in carbon molecular sieves

A dual resistance model with distribution of either barrier or pore diffusional activation energy is proposed in this work for gas transport in carbon molecular sieve (CMS) micropores. This is a novel approach in which the equilibrium is homogeneous, but the kinetics is heterogeneous. The model seems to provide a possible explanation for the concentration dependence of the thermodynamically corrected barrier and pore diffusion coefficients observed in previous studies from this laboratory on gas diffusion in CMS. The energy distribution is assumed to follow the gamma distribution function. It is shown that the energy distribution model can fully capture the behavior described by the empirical model established in earlier studies to account for the concentration dependence of thermodynamically corrected barrier and pore diffusion coefficients. A methodology is proposed for extracting energy distribution parameters, and it is further shown that the extracted energy distribution parameters can effectively predict integral uptake and column breakthrough profiles over a wide range of operating pressures.     

化学蒸气沉积硅氧化合物调变HZSM－5沸石的研究

本文研究了正硅酸乙酯分别在无胺法和有胺法制得的ＨＺＳＭ－５沸石上的沉积过程，并用吸附，ＮＨ３－ＴＰＤ及异丙醇探针反应等手段表征了沉积后的样品，发现沉积仅在外表面上进行，可使孔口变小但不影响孔道内性质，显示有对于二甲苯分子的择形吸附能力，且在甲苯甲醇烷基化反应和二甲苯异构化反应中表现出良好的择形催化性能．     

铽(Ⅲ)-1,4-双(1′-苯基-3′-甲基-5′-氧代吡唑-4′-基)丁二酮-[1,4]体系荧光性质的研究及应用

本文研究了Tb(Ⅲ)-1,4-双(′-苯基-3′-甲基-5′-氧代吡唑-4′-基)丁二酮-[1,4](BPMPBD)-溴化十六烷基三甲胺(CTMAB)体系的荧光性质,探讨了响影体系荧光性质的诸因素,确定了最佳实验条件。该体系中Tb(Ⅲ)浓度以2.0×10~(-5)～1.0×10~(-10)mol/L范围内与其荧光强度呈线性关系,检测限可达到5.0×10~(-11)mol/L。应用于合成样品中微量Tb(Ⅲ)的分析,结果令人满意。     

Synthesis and Investigation of Indium Dodecatungstosilicate

Indium dodecatungstosilicate of the composition [In(OH)⋅5H₂O]₂ [SiW₁₂O₄₀]⋅H₂O is synthesized and studied by means of IR spectroscopy, thermogravimetry, and X-ray phase analysis. The crystals of this compound are triclinic, space group P1, a 13.079(3), b 13.795(3), c 13.967(3) Å, α 90.08(3)°, β 103.76(3)°, ψ107.76(3)°, Z 2, and π_calc 4.900 g cm⁻³.__________Translated from Zhurnal Obshchei Khimii, Vol. 75, No. 1, 2005, pp. 21–23.Original Russian Text Copyright © 2005 by Kaziev, Dutov, Quinones, Ita, Sychkin.     

Synthesis and biological evaluation of 3-{[4-(4-[18F]fluorophenyl)methyl] piperazin-1-yl}-methyl-1H-pyrrolo[2,3-b]pyridine for in vivo studies of dopamine D4 receptor

The compound 3-{[4-(4-[¹⁸F]fluorophenyl)methyl]piperazin-1-yl}-methyl-1H-pyrrolo[2,3-b]pyridine ([¹⁸F]3), which is an analogue of L-745,870 binding D₄ This revised version was published online in July 2006 with corrections to the Cover Date.     

Absorption and Capture of Methane into Ionic Liquid

A reversible storage-release process switched by a temperature difference of 10℃around room temperature can be realized. This fast, recyclable, energy efficient, low cost and green system within a wide range of temperature and pressure is reported here for the first time. The system is believed to open up a new route for the storage and homogeneous utilization of methane.     

Modeling the reaction mechanisms for redox regulation of protein tyrosine phosphatase 1B activity

Protein tyrosine phosphatase 1B (PTP1B) functions by removing the phosphoryl group from tyrosinephosphorylated proteins in insulin signaling and metabolism. The regeneration of the active site involves a sulphenylamide intermediate derived from the intrastrand cross-linking between the catalytic serine and the neighboring backbone nitrogen. Two mechanisms have been proposed for the formation of the sulphenylamide intermediate and the subsequent reactivation of the catalytic site. In the current work, the proposed mechanisms have been investigated by the use of density functional theory calculations. Our results suggest that these two mechanisms have similar overall energy barriers and that the preferred route will be determined by the availability of hydrogen peroxide or other oxidizing reagents.