溶剂对螯合物稳定性的影响：镉（Ⅱ）—甘氨酸（苯丙氨酸）—乙醇／…

用ＰＨ－电位滴定法测定了３７℃、Ｉ＝０．１ｍｏｌ．ｄｍ＾－３（ＫＮＯ３）、乙醇／水混合溶剂中配合物Ｃｄ（Ａａ）ｎ（Ａａ－＝甘氨酸、苯丙氨酸，ｎ＝１，２的一、二级稳定常数ｌｇｋ１、ｌｇｋ２及配体Ａａ＾－的酸解离常数ｐｋ１、ｐｋ２。     

配合物稳定性和配体酸碱强度之间的直线自由能关系──铜（Ⅱ）、锌（Ⅱ）－芬布芬－α－氨基酸三元配合物体系

在２５±０．１℃，Ｉ＝０．１ｍｏｌ·ｄｍ－３ＫＮＯ３条件下，８０％（ｖ／ｖ）ＤＭＳＯ—Ｈ２Ｏ混合溶剂中，应用ｐＨ法测定了甘氨酸，Ｌ一缬氨酸，Ｌ－异亮氨酸，Ｌ－脯氨酸，Ｌ－丝氨酸，ＤＬ－苯丙氨酸等六种α－氨基酸（缩写为α－ＡＡ，记为Ｂ配体）的酸离解常数，铜（Ⅱ）－α－氨基酸．锌（Ⅱ）－α－氨基酸二元配合物的稳定常数及铜（Ⅱ）－芬布芬－α－氨基酸（芬布芬缩写为Ｆｅｎ，记为Ａ配体）和锌（Ⅱ）－芬布芬－α－氨基酸三元配合物的稳定常数．实验发现，在下面三对参数之间，即ｌｏｇβ１０２与ｐＫ，ｌＯｇβ１１１；与ｐＫ及１０ｇβ１１１与ｌｏｇβ１０２，均存在良好的直线自由能关系．用△ｌｏｇＫＭ和△ｌｏｇβ１１１两个参量描述了三元配合物相对于母体二元配合物的稳定性．讨论了溶剂的性质，配合物分子内配体之间的疏水作用，芳环之间的堆积作用对配合物稳定性的影响．     

荧光法测定β－CD与萘酚负离子包结物的解离常数和β－CD与分子型萘酚包结物的酸式离解常数

本文提出了一种利用β－ＣＤ包结物与酸碱离解平衡关系，用荧光法间接测定β－ＣＤ包结物解离常数的新方法。并测定了β－ＣＤ分别与１－萘酚和２－萘酚负离子包结物的解离常数ｐＫｂ为２．５８和３．２７，β－ＣＤ与分子型体１－萘酚和２－萘酚包结物的酸式离解常数ｐＫｃ分别为１０．４２和０．６８。     

新显色剂2—（5—羧基—1,3,4—三氮唑偶氮—5—二乙氨基酚的合成及其与？…

首次合成了新显色剂２－（５－羧基－１，３，４－三氮唑偶氮）－５－二乙氨基酚，研究了它的性质及其与铋是色反应的条件。结果表明：试剂的分子式Ｃ１８Ｈ１６Ｎ６Ｏ３，分子量３０４．３２，ｍ．ｐ．２５２℃，各级酸离解常数为ｐＫａ１＝３．１，ｐＫａ２＝７．５，ｐＫａ３＝９．６；在ｐＨ７的ＮＨ４Ａｃ介质中，试剂与铋形成紫红色络合物，λｍａｘ为５４０ｎｍ，对比度Δγ为１２０ｎｍ，络合物的ＮＨ４Ａ介质中，试剂与铋形     

水/乙醇混合溶剂中氨基酸离解的取代基效应

用LKB-2277BioActivityMonitor测定了298.15K时甘氨酸,丙氨酸和丝氨酸在水/乙醇混合溶剂中的离解焓,计算了相应的离解熵。根据三个氨基酸分别与某一参考酸之间的质子交换反应,重点讨论了溶剂结构变化对取代基效应焓,熵变化的影响。实验结果表明在水/乙醇混合溶剂的最大结构化区域,取代基效应最为显著。认为在混合溶剂的富水区大块的似冰山结构的水分子簇的寿命大大延长。     

溶剂对螯合物稳定性的影响——镉(Ⅱ)-甘氨酸(苯丙氨酸)-乙醇/水体系

用ｐＨ－电位滴定法测定了３７℃、Ｉ＝０．１ｍｏｌ·ｄｍ－３（ＫＮＯ３）、乙醇／水混合溶剂中（Ｖ／Ｖ％）配合物Ｃｄ（Ａａ）ｎ（Ａａ－＝甘氨酸（ｇｌｙ－）、苯丙氨酸（ｐｈｅ－），ｎ＝１，２）的一、二级稳定常数ｌｇｋ１、ｌｇｋ２及配体Ａａ－的酸解离常数ｐｋ１、ｐｋ２。结果表明，对于Ｃｄ－ｇｌｙ体系，ｌｇｋ１、ｌｇｋ２均与ｇｌｙ－的碱性强度ｐｋ２呈良好的线性关系，对Ｃｄ－ｐｈｅ体系，仅ｌｇｋ１与ｐｈｅ－的ｐｋ２呈线性关系，而ｌｇｋ２与ｐｋ２则为曲线关系。从溶剂化角度和配体间疏水相互作用观点对上述结果进行了讨论。     

2—羟基苄叉罗丹宁合成及用作钯的光度试剂

本文报道新试剂２－羟基苄叉罗丹宁的合成，用分光光度法测定２－ＨＢＲ的离解常数，ＰＫａ１＝９．４３，ｐＫａ２＝１１．７１。研究了２－ＨＢＲ与钯的配位反应。     

光度法测定甲基橙和二甲基黄在甲醇—水混合溶剂中的离解常数

利用光度法测定了酸碱指示剂甲基橙（ＭＯ）和二甲基黄（ＤＹ）在０％～９０％（Ｖ／Ｖ）和３５％～８４％（Ｖ／Ｖ）甲醇－水混合溶剂中的离散常数ｐＫａ（２５℃，离子强度Ｉ＝０．１ｍｏｌ／ＬＫＣｌ）实验结果表明，随着混合溶剂中甲醇含量的增加，两种指示剂的ｐＫａ均不断减小，当混合溶液中甲醇含量小于７５％时，ｐＫａ同甲醇的摩尔分数Ｘ２之间存在着良好的线性关系。甲醇的加入，指示剂在可见光区的吸收光谱有较明显的改变     

安替比林基重氮基—2,4—二硝基苯及其与镉的显色反应

合成了安替比林基重氮氨基－２，４－二硝基苯（ＡＰＤＮＢＴ）新试剂，并首先研究了它的分析性质及其与镉的显色反应。在ＴｒｉｔｏｎＸ－１００存在下，试剂的两级质子离解常数的ｐＫａ值分别是０．８和１０．８；在ｐＨ＝１０．２～１２．０的Ｂ－Ｒ缓冲溶液中，试剂与镉生成１：２的黄色配合物，呈褪色反应，吸光度差值最大的波长为５４０ｎｍ，其表观摩尔吸光系数为１．５２×１０＾５Ｌ／（ｍｏｌ．ｃｍ），线性范围每２５ｍＬ     

介质对配合物稳定性的影响──Ⅶ．Cu（CTS）~（2－）－NaCl_4－C_2H_5OH－H_2O体系

用分光光度法于２９３±１Ｋ温度下测定了由二价阳离子Ｃｕ（２＋）和高价阴离子（ＣＴＳ）（４－）（３，６－二磺酸根－１，８－二羟基萘酚）形成配阴离子Ｃｕ（ＣＴＳ）（２－）在乙醇－水混合溶剂中的稳定常数随离子强度的变化．溶剂中乙醇的重量百分数分别为０、１０、２０、３０、４０和５０；每个混合溶剂中的离子强度均为０．１－３．０ｍｏｌ·ｄｍ（－３）．分别用推广的Ｄｅｂｙｅ－Ｈｕｃｋｅｌ方程［１］和Ｐｉｔｚｅｒ方程［２］计算了配离子的热力学稳定常数．发现对本体系Ｄｅｂｙｅ－Ｈｕｃｋｅｌ方程完全不能适用，而基于Ｐｉｔｚｅｒ方程的多项式逼近法［３］则可得到满意的结果．简单讨论了介质效应和配位反应的标准迁移自由能．     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

恶臭嗅辨实验室建设探讨

针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。     

Investigation of Kinetics of Solid-Phase Synthesis of Lithium Orthosilicate

The kinetics of the interaction between lithium carbonate and silica with various degrees of dispersion was investigated by TG and DTA methods. It was found that the utilization of pyrogenic silica with a specific surface area of about 300 m²g^-1 instead of aerosil with one of 175 m²g^-1 leads to an increase of the reaction rate between lithium carbonate and silica, which depends on the formation and growth of lithium orthosilicate crystals in the first stage, and is conditioned by the diffusion of lithium and oxygen ions through the lithium orthosilicate layer formed at temperatures above 800 K. This supposition is supported by the kinetic analysis results obtained with the use of the different models. The optimal regime of heating is recommended. This revised version was published online in July 2006 with corrections to the Cover Date.     

小环化合物中饱和碳质子化学位移的计算

小环化合物由于其张力、构型、构象和各向异性效应等原因,环碳上质子化学位移缺乏规律性,难以预测,对此作者曾提出一种近似算法。本文根据303种小环化合物中饱和碳质子的化学位移实验数据,将适于计算这类质子化学位移的公式表述为:     

解决能源问题的新途径--光解水制氢的研究

面对日益枯竭的能源危机,氢能是一种洁净、最有前景的替代能源。目前在各种制氢的方法中光催化分解水制氢的研究最多,光解水过程中催化剂最关键,本文对利用太阳能光解水的途径、提高光催化反应效率以及光催化剂的开发研究进行了综述。