最小二乘阻尼算法用于复方药物光度分析

最小二乘阻尼算法用于复方药物光度分析邱细敏，曾鸽鸣，刘亚凤，柳爱萍，李志良（湖南医专长沙４１０００６，湖南大学化学化工系长沙４１００８２）１前言多组分光度分析是当前较活跃的研究领域之一￣［１－４］，已应用到许多化学计量学（ｃｈｅｍｏｍｅ－ｔｒｉｃｓ）...     

聚氯乙烯负载席夫碱树脂的合成及其对金属离子的吸附

聚氯乙烯负载席夫碱树脂的合成及其对金属离子的吸附刘理中，俞善信，肖立新（湖南师范大学化学系长沙４１００８１）（中南工业大学冶金化学研究所长沙）关键词聚氯乙烯，负载树脂．席夫碱，金属离子，吸附高分子负载席夫碱可用于离子吸附和催化等领域，汪信［１，２］等...     

镍基溅射钨注碳电极的催化性能

镍基溅射钨注碳电极的催化性能张季爽，吕瑶姣，李青莲（湖南大学化学化工系环境工程系，长沙４１００８２）沈报恩（杭州大学化学系，杭州３１００２８）析氢反应研究涉及到氢能、燃料电池、氯碱工业等的能源开发及节能技术，并具有重要的理论意义￣［１～５］．本工作研...     

新型氨喷泉实验

新型氨喷泉实验李劲，彭爱芝（湖南医科大学化学教研室，长沙４１００７８）氨喷泉实验是天机化学实验中最经典的实验之一。通过观察氨溶于水形成喷泉，说明氨是在水中溶解度很大的气体￣［１］。但以往教科书中常用的方法是通过加热铵盐和碱的混合物来制取氨以进行喷泉实...     

利用荧光能量转移设计高灵敏苦味酸光极膜

利用荧光能量转移设计高灵敏苦味酸光极膜王柯敏，曾恚恚，俞汝勤（湖南大学化学化工系，长沙，４１００８２）关键词荧光能量转移，光极，苦味酸基于稠环芳烃荧光熄灭的苦味酸光极膜［１ａ，２］在选择性方面优于传统苦味酸根离子电极，较适于实际应用，但在检测低浓度苦...     

N，N＇－二（乙酰芳香环）－穴醚［2，2］的合成

Ｎ，Ｎ＇－二（乙酰芳香环）－穴醚［２，２］的合成余江，许振华，徐光宪（北京大学化学与分子工程学院，稀土材料化学及应用国家重点实验室，北京，１００８７１）关键词大环，穴醚［２，２］，ＨＴＴＡ穴醚（Ｃｒｙｐｔａｎｄ）是含有Ｏ及Ｎ和Ｓ等杂原子的多聚大环化合...     

无金属酞菁中杂质硫的化学价态

无金属酞菁中杂质硫的化学价态周淑琴金祥凤刘世宏（中国科学院化学研究所北京１０００８０）作为有机光导材料的酞菁化合物在静电复印特别是激光印刷机中是重要的载流子产生材料之一［１，２］，在研究酞菁双层感光膜［３］和杂质分析［４］中，发现无金属酞菁中微量杂质...     

室温固-固反应示例

室温固固反应示例陈天牛忻新泉（南京大学配位化学研究所江苏２１００９３）固相反应由于扩散速度的限制，通常认为必须在高温下进行［１］，我们发现某些固相反应不仅在室温或近室温的条件下可以发生［２］，而且可以迅速完成［３］。这里介绍一个在室温（大约２０℃）...     

人工神经网络法预测有机物临界体积研究

人工神经网络法预测有机物临界体积研究张向东（辽宁大学化学系沈阳１１００３６）赵立群，张国义（沈阳化工学院高分子化工系１１００２１）１基本原理￣［１］最近几年国内外学者将人工神经网络方法应用于解决化学问题收到较好效果￣［２］。误差反向传播（ＢＰ）模型是...     

氰桥配合物K［L_2FCr~（III）－NC－Cr~I（CN）_4NO］的合成

氰桥配合物Ｋ［Ｌ＿２ＦＣｒ￣（ＩＩＩ）－ＮＣ－Ｃｒ￣Ｉ（ＣＮ）＿４ＮＯ］的合成与性质展树中，孟庆金，戴安邦（南京大学配位化学研究所，国家重点实验室２１００９３）随着超分子化学的迅速发展￣［１］，许多新型结构配合物和具有特殊功能的配合物相继被合成出来，...     

不饱和醇电还原质谱-电化学循环伏安(MSCV)法研究:I.烯丙醇的电还原

用MSCV法研究了烯丙醇在多孔Pt电极上0.5ol.dm^-3HCLO4中的电还原。烯丙醇电还原时主要涉及二类反应:烯丙基上C-OH断键生成丙烯; 丙烯进一步氢化生成丙烷。表征丙烯及丙烷的诸碎片M/Z的质谱电流(IM)-电极电位(Φ)扫描曲线线详细描绘了各分步反应的状况。在一定电位范围, 各M/Z的lgIM-Φ呈线性; 求得各有关M/Z的Tafel斜率。根据实验结果对反应机理进行了详细分析。     

不饱和醇电还原的质谱-电化学循环伏安(MSCV)法研究:II.炔丙醇的电还原

炔丙醇在多孔Pt黑电极上, 0.5mol.dm^-3HCLO4溶液中电还原的MSCV研究结果表明炔丙醇电还原时既涉及烯丙基C-OH断键反应亦涉及炔丙基上C-OH断键反应生成烃类。此外有少量炔丙醇直接质子化生成部分饱和的烯丙醇。表征各种反应产物的M/Z的质谱电流-电极电位扫描曲线(IM-Φ)详细描绘了各分步反应的图象。各M/Z的1gIM-Φ曲线在一空电位范围内呈线性, 并求得它们的Tafel斜率。依据实验结果对反应机理进行了详细分析。     

Reductive cleavage of C-OH bonds in allyl position-formation of gaseous products in the course of the cathodic reduction of some simple unsaturated alcohols

The problem of the reductive cleavage of C?OH bonds in allyl position has been considered starting from the literature data concerning the behaviour of allyl alcohol. The formation of hydrocarbons has been shown in the case of the electroreduction of crotyl alcohol, 2-butene-1,4-diol, propargyl alcohol, 2-butyne-1,4-diol and 1-butyne-3-ol. The composition of the gaseous products was analyzed, current efficiency values with respect to the hydrocarbon formation were calculated. Schemes for the reduction path were given.     

Mechanism of electroreduction of allyl alcohol at platinized platinum electrode in acidic aqueous solution.

The electroreduction of allyl alcohol to form propene at the platinized platinum electrode in acidic aqueous solution has been studied using CV plots, IR, ESR, and MS spectra, and a semiempricial MO method (MOPAC7/AM1, PM3). From the determinations of charge-transfer coefficients, reaction orders and apparent activation energy for the given reaction, the detection of the intermediates such as C(3)H(5)(+), C(3)H(5)(*), and C(3)H(5)(-) species, and PM3 calculations of charge distribution and frontier orbital energies of the reaction species C(3)H(5)OH and C(3)H(5)(+), the authors suggest that in acidic aqueous solution the production of propene via reductive splitting of the C-OH bond situated in the allyl position of allyl alcohol obeys a carbonium ion-carbanion mechanism.     

炔丙醇电还原自由基中间产物的ESR研究

Electrochemical-ESR technique (ex situ method) with spin traps phenyl tert-butyl nitrone (PBN) and 5,5-dimethyl-1-Pyrroline-1-oxide (DMPO) has been applied to the detection of radical intermediates produced during electroreduction of propargyl alcohol (PA) at platinized platinum electrode in an acidified alcohol-aqua solution. Propargyl radical and H have been detected by PBN and DMPO, respectively. As a result of the discovery of these radicals, an evidence for a radical mechanism of the electroreduction of PA put forward by some authors might be obtained beyond all doubt.     

Inter- and intramolecular pathways for the formation of tetrahydrofurans from beta-(Phosphatoxy)alkyl radicals. Evidence for a dissociative mechanism

beta-(Phosphatoxy)alkyl radicals generated by photolysis of Barton PTOC esters in the presence of allyl alcohol and tert-butyl mercaptan undergo nucleophilic substitution followed by 5-exo-trig radical ring closure leading to tetrahydrofurans in good yield and with high trans selectivity. beta-(Phosphatoxy)alkyl radicals obtained by intramolecular hydrogen 1,5-abstraction with an alkoxyl radical undergo nucleophilic displacement providing tetrahydrofurans. The ensemble of results, including the effects of leaving groups and substituents, strongly support a dissociative mechanism for these radical nucleophilic displacement reactions.     

A New Radical Allylation Reaction of Dithiocarbonates

A radical allylation reaction without tin: The xanthate group in aliphatic xanthates can be replaced by an allyl unit [Eq. (a)]. This radical chain reaction is propagated by ethyl radicals generated by extrusion of sulfur dioxide from ethanesulfonyl radicals, which are themselves derived from allyl ethyl sulfone.     

Trimethyl phosphite as a trap for alkoxy radicals formed from the ring opening of oxiranylcarbinyl radicals. Conversion to alkenes. Mechanistic applications to the study of C-C versus C-O ring cleavage

Trimethyl phosphite, (MeO)(3)P, is introduced as an efficient and selective trap in oxiranylcarbinyl radical (2) systems, formed from haloepoxides 8-13 under thermal AIBN/n-Bu(3)SnH conditions at about 80 degrees C. Initially, the transformations of 8-13, in the absence of phosphite, to allyl alcohol 7 and/or vinyl ether 5 were measured quantitatively (Table 1). Structural variations in the intermediate oxiranylcarbinyl (2), allyloxy (3), and vinyloxycarbinyl (4) radicals involve influences of the thermodynamics and kinetics of the C-O (2 --> 3, k(1)) and C-C (2 --> 4, k(2)) radical scission processes and readily account for the changes in the amounts of product vinyl ether (5) and allyl alcohol (7) formed. Added (MeO)(3)P is inert to vinyloxycarbinyl radical 4 and selectively and rapidly traps allyloxy radical 3, diverting it to trimethyl phosphate and allyl radical 6. Allyl radicals (6) dimerize or are trapped by n-Bu(3)SnH to give alkenes, formed from haloepoxides 8, 9, and 13 in 69-95% yields. Intermediate vinyloxycarbinyl radicals (4), in the presence or absence of (MeO)(3)P, are trapped by n-Bu(3)SnH to give vinyl ethers (5). The concentrations of (MeO)(3)P and n-Bu(3)SnH were varied independently, and the amounts of phosphate, vinyl ether (5), and/or alkene from haloepoxides 10, 11, and 13 were carefully monitored. The results reflect readily understood influences of changes in the structures of radicals 2-4, particularly as they influence the C-O (k(1)) and C-C (k(2)) cleavages of intermediate oxiranylcarbinyl radical 2 and their reverse (k(-1), k(-2)). Diversion by (MeO)(3)P of allyloxy radicals (3) from haloepoxides 11 and 12 fulfills a prior prediction that under conditions closer to kinetic control, products of C-O scission, not just those of C-C scission, may result. Thus, for oxiranylcarbinyl radicals from haloepoxides 11, 12, and 13, C-O scission (k(1), 2 --> 3) competes readily with C-C cleavage (k(2), 2 --> 4), even though C-C scission is favored thermodynamically.     

Kinetics and mechanisms of OH‐initiated oxidation of small unsaturated alcohols

Smog chamber relative rate techniques were used to measure rate coefficients of (5.00 ± 0.54) × 10^?11, (5.87 ± 0.63) × 10^?11, and (6.49 ± 0.82) × 10^?11 cm³ molecule^?1 s^?1 in 700 Torr air at 296 ± 1 K for reactions of OH radicals with allyl alcohol, 1‐buten‐3‐ol, and 2‐methyl‐3‐buten‐2‐ol, respectively; the quoted uncertainties encompass the extremes of determinations using two different reference compounds. The OH‐initiated oxidation of allyl alcohol in the presence of NO_x gives glycolaldehyde in a molar yield of 0.85 ± 0.08; the quoted uncertainty is two standard deviations. Oxidation of 2‐methyl‐3‐buten‐2‐ol gives acetone and glycolaldehyde in molar yields of 0.66 ± 0.06 and 0.56 ± 0.05, respectively. The reaction of OH radicals with allyl alcohol, 1‐buten‐3‐ol, and 2‐methyl‐3‐buten‐2‐ol proceeds predominately via addition to the >C?CH₂ double bond with most of the addition occurring to the terminal carbon. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 42: 151–158, 2010     

对甲苯磺酰胺电还原过程的电化学-ESR研究

对一些含硫的镀镍光亮剂电还原反应曾提出过两种反应机理，一种是生成硫酸的机理，一种是脱磺酸（酞）基团的机理．Brook和Crossleyu］认为这类反应是按后一种机理进行的自由基反应，但未对中间产物作出检测．因此目前对反应机理尚无定论．为了阐明还原中间产物与反应本性，本文利用自旅捕集技术与UV光谱研究了对甲基磺欧胺在汞电机上的电还原过程．1实验1．1仪器HDVI－xFD｛－x－Y仅组装CV图测量系统；日本JE巳FElxG波谱仪；xJP七ZI新极谱仪阳春应化所）2751G紫外分光光度计．1．2主要试剂苯亚甲基叔丁基氮氧化物（PBN，由中科…