Research on catalysis of sodium-metallochlorophylls in Ni/MH battery

The effects of sodium-metallochlorophylls including sodium-iron chlorophyllin, sodium-copper chlorophyllin and sodium-magnesium chlorophyllin on performance of Ni/MH battery were investigated. The results show that sodium-iron chlorophyllin can effectively activate the gases produced during charge in Ni/MH battery, therefore reducing the reduction potential of oxygen and the oxidation potential of hydrogen, and the increased speed of inner pressure of battery is decreased significantly. With the aid of DMol3 software, the activation process of oxygen and hydrogen by sodiummetallochlorophylls was simulated and analyzed. It was found that the catalysis behavior is in agreement with the experimental results, and the activation process also gets a reasonable explanation from the calculated results.     

含N-吗啉乙基茚基配体镱金属配合物的合成、表征及催化性能的研究

用化合物3-[O(CH2CH2)2NCH2CH2]C9H7(1)与1当量的n-BuLi反应接着再与过量的Me3SiCl反应,以90%的产率得到1-Me3Si-3-[O(CH2CH2)2NCH2CH2]C9H6(2).化合物1、2分别以当量比2:1与化合物[(Me3Si)2N]3YbⅢ(μ-Cl)Li(THF)3在甲苯中回流反应,分别以65%和55%的产率得到二价镱化合物[η5:η1-O(CH2CH2)2NCH2CH2C9H6]2YbⅡ(3)和[η5:η1-O(CH2CH2)2NCH2CH2C9H5SiMe3]2YbⅡ(4).化合物2,3,4经过波谱及元素分析表征确认.研究了配合物3和4作为单一组分催化剂催化己内酯聚合反应的催化活性.     

酶促棕榈酸鲸蜡酯合成的底物抑制作用

对实验室自制的固定化Candida sp. 99-125脂肪酶在正己烷中催化棕榈酸和鲸蜡醇的酯化反应的动力学机制进行了初步研究,结果表明：反应为动力学控制,不存在扩散限制,底物浓度对反应速率的影响符合Ping-Pong Bi-Bi反应机制。但在不同的底物浓度范围内存在不同程度的底物抑制作用,其中以长链醇的抑制为主。本文根据底物浓度由低到高,划分了三个底物浓度范围,在不同的范围内分别研究了两个底物的抑制作用,并选择不同的动力学模型,求得了动力学常数。     

相转移催化合成对苯乙炔聚合物发光材料中间体4-丁氧基苯酚的研究（Ⅰ）

 近几年来二烷氧基取代对苯乙炔聚合物(PPV)发光功能材料广泛应用于液晶彩电、电脑等家电和飞机彩色液晶显示屏中,该文研究了利用相转移催化反应在不同的催化剂反应条件下,合成二烷氧基取代对苯乙炔聚合物(PPV)发光功能材料的中间体4-丁氧基苯酚,在氢氧化钠存在下对苯二酚与溴代正丁烷60~65 ℃反应3 h条件下合成4-丁氧基苯酚,产品收率达90%以上。对不同的催化剂的使用和反应时间进行了条件优化,对产品4 丁氧基苯酚的IR谱图、NMR谱图进行了确认和详细的分析。     

生理温度下苯丙氨酸-葡萄糖模式体系Maillard反应的影响因素研究

测试了D-葡萄糖和L-苯丙氨酸在37℃,pH 6.5的条件下反应1～35 d所得Maillard反应产物的颜色强度,研究了溶剂水分含量以及金属离子Fe2+,Cu2+对D-葡萄糖和L-苯丙氨酸模式Maillard反应体系的影响.结果表明:在本实验条件下模式体系Maillard反应速率和体系水分含量成反比关系,随着水分含量的降低反应速率逐渐升高;金属离子Fe2+,Cu2+能促进模式体系Maillard反应,有效缩短反应时问,并且随着金属离子浓度的增加其催化作用先增强后减小;当Fe2+,Cu2+的浓度为0.2 mmol/L时,其催化作用最强,并且Cu2+的催化作用大于Fe2+.     

纤维素月桂酸酯的制备及其结构和性能表征

在均相体系下,以微晶纤维素为原料,以月桂酰氯为酯化试剂,吡啶为催化脱酸剂制备纤维素月桂酸酯,研究了酯化试剂用量、反应温度、反应时间对纤维素月桂酸酯取代度和得率的影响,确定了合成纤维素月桂酸酯的适宜条件为：酰氯用量16 mol（基于纤维素上羟基摩尔数）,反应温度100 ℃,反应时间10 h,此时纤维素月桂酸酯的得率为3108 %,取代度达248。采用红外光谱和核磁共振氢谱对纤维素月桂酸酯的结构进行了表征,证明了纤维素已发生酯化反应。接触角实验结果表明,所得纤维素月桂酸酯的接触角随取代度增加而增加,取代度>16时产物具有极强的疏水性。     

碳酸铯催化下烷基芳醚的制备

研究了碳酸铯催化酚与卤代烃反应制备烷基芳醚．以碳酸铯作催化剂,氢氧化钾作碱,DMF作溶剂,室温下,在分子筛存在下,苯酚、萘酚、3,5-二叔丁基苯酚及4-[二(4 -叔丁基苯基)苯基甲基]苯酚与溴乙烷、溴丁烷及苄溴等反应形成相应的烷基芳醚,收率为90%～96%．结果表明,碳酸铯可有效地催化酚与卤代烃反应．     

含铌硅磷铝双功能分子筛催化剂的合成及结构表征

合成了铁磷铝(FeAPO-5)、铁硅磷铝(FeSAPO-5)和铌铁硅磷铝(NbFeSAPO-5)分子筛催化剂,并采用XRD、红外光谱和固体魔角旋转核磁共振等方法对合成的催化剂进行了结构表征。结果表明:合成的分子筛具有AlPO4-5的骨架结构,并且铁、硅和铌金属杂原子进入了分子筛骨架。以丙酮醛和甲醇作为合成丙酮酸甲酯的原料,考察了NbFeSAPO-5分子筛催化剂的催化氧化及催化酯化性能,结果表明铁元素进入分子筛骨架使催化剂具有良好的催化氧化性能,而硅和铌的引入提高了分子筛的酸性和催化酯化性能,使NbFeSAPO-5分子筛催化剂成为同时具有催化氧化和催化酯化性能的双功能催化剂。     

Modulation of protein biophysical properties by chemical glycosylation: biochemical insights and biomedical implications

Glycosylation constitutes one of the most important posttranslational modifications employed by biological systems to modulate protein biophysical properties. Due to the direct biochemical and biomedical implications of achieving control over protein stability and function by chemical means, there has been great interest in recent years towards the development of chemical strategies for protein glycosylation. Since current knowledge about glycoprotein biophysics has been mainly derived from the study of naturally glycosylated proteins, chemical glycosylation provides novel insights into its mechanistic understanding by affording control over glycosylation parameters. This review presents a survey of the effects that natural and chemical glycosylation have on the fundamental biophysical properties of proteins (structure, dynamics, stability, and function). This is complemented by a mechanistic discussion of how glycans achieve such effects and discussion of the implications of employing chemical glycosylation as a tool to exert control over protein biophysical properties within biochemical and biomedical applications. Received 15 December 2006; received after revision 28 March 2007; accepted 25 April 2007     

微波辐射对甲苯磺酸催化合成丙酸异戊酯

在常压、微波辐射条件下,以对甲苯磺酸为催化剂,以丙酸和异戊醇为原料,合成了丙酸异戊酯。实验结果表明：催化剂对甲苯磺酸的用量为0．25 g,丙酸的用量为0．2 mol,异戊醇的用量为0．60 mol,微波辐射功率为750 W,辐射回流时间为12 min,酯化率可达96．6%。与常规加热方法相比,具有反应速度快、转化率高等优点。