有机磷化合物的电子结构与成键

本文叙述了有机磷化合物的成键与性质,以及在理论上的新发展,分下面两个内容讨论:(1)磷原子的性质与成键。(2)各类有机磷化合物的电子结构与成键。     

羧酸类化合物的结构和萃取性能的相关性

应用量子化学参数研究羧酸类化合物的结构与其萃取性能的相关性,并将二维结构参数应用到三维构效关系研究中,从而有效地改善了CoMFA法的结果,用pK_a值来表征羧酸类化合物的萃取性能.     

赝势平面波计算铀及铀化合物结构研究

Ultrasoft pseudopotential was generated for uranium and the plane waves pseudopotential formalism was used to study its crystal structures at zero temperature as a function of pressure. The alpha phases of uranium were fully relaxed. The zero-pressure zero-temperature equilibrium volumes and bulk moduli are consistent with previous calculations, and in excellent agreement with the experiment. This is also the case for cell parameters and pressure-induced phase transitions. In the calculation of NaCl and CaF2 structure type of compound of uranium, the difference of theoretical lattice constant and the experimental value is less than 3%. For UO2+x the trend of the lattice shinking with the x value increase is in accord with the experiment. For large U2C3 and U2N3 complex cells the difference of theoretical lattice constant and the experimental value is less than 3%, and the difference of coordination of atom is less than 5%.     

有机磷配位体的结构与性能

有机磷化学是一门历史悠久的学科,由于这类化合物的生理作用显著(核酸、辅酶的组成部分及神经毒剂、农用杀虫、杀菌、除草剂、植物生长剂和化学治疗剂等),工艺性能良好(增塑剂、萃取剂、溶络剂、水质稳定剂、防火剂、石油添加剂和表面活性剂等)以及在有     

模式识别与化学信息处理

近年来,我们建立了一套模式识别软件系统,并用于有关材料学、催化剂筛选、石油的地球化学勘探等方面的化学信息处理,取得了显著效果.本文介绍我们采用的模式识别方法.     

3C化学位移与某些杂环化合物的取代反应

~（１３）Ｃ化学位移与某些杂环化合物的取代反应丁金昌（温州师范学院化学系３２５００３）近年来，杂环化合物在有机化学领域中发展很快，已越来越引起人们的重视。在杂环化合物的合成中，除了需合成一些杂环母核外，更多的是需要合成环上带有取代基的化合物，这些环上?..     

碱金属萃取化学的研究 III:弱酸性偶氮螯合剂化学结构对萃取锂的性能研究

The synergistic extractic extraction of lithium with a solution of o-phenylazophenols (HAX) and trioctylphosphine oxide (TOPO) or other trialkylphosphine oxide (TRPO, R = C8-10) in o-dichlorobenzene from aqueous solution of lithium hydroxide was reported. The structural effect of o-phenylazophenols on extraction of lithium has been examined. In the case of 1-(p-X-phenylazo)-2-naphthols, the HMO calculation shows that the charge density of azo nitrogen atom(the donor atom, denote azo N) and hydroxyl oxygen atom does not very apparently, so that the stability of their chelates with lithium has no obvious variations as well. In this case their ability to extract lithium is chiefly governed by the pKa. of the compound. The results of extraction prove that there is a linear correlation between the extraction constant Kex and pKa. However, for the second group of chelating agents, the change of their structure leads to the change of the change of both pKa and stability of chelates. The results of extraction and HMO calculation show that the stability of chelates is mainly influenced by the strength of the coordination bond, i.e. the larger the charge density of azo N (qN), the more stable the chelate will be. Therefore, their ability to extract lithium is roughly directly proportional to the stability of chelates and inversely to the pKa. the strength of coordination bond for the chelates can be experimentally measured by means of the strength of intramolecular hydrogen bond of chelating agent, ΔδOH (the diference of chemical shift of hydroxyl proton in free and bonded state). Therefore, the ratio, ΔδOH/pKa, can be used to evaluate the extraction ability of chelating agents to lithium. We find that it is approximately proportional to the distribution ratio (D).     

碱金属萃取化学的研究 Ⅲ.弱酸性偶氮螯合剂化学结构对萃取锂的性能影响

本文通过对-取代苯基偶氮-2-萘酚及邻-取代苯基偶氮-芳香酚两种类型共十一种螯合剂与TOPO(或TRPO)协草锂的性能研究及HMO计算,讨论了该类螫合剂与中性协萃剂协萃锂时的结构效应。结果表明:(1)对-取代苯基偶氮-2-萘酚类赘合剂的苯基偶氮的配键N原子的电荷密度q_N与羟基氧原子的电荷密度qo_H无明显变化,萃取能力只受螯合剂pK_a的影响,协萃锂的表观平衡常数随整合剂pK_a值的下降而上升;(2)邻苯基偶氮-芳香酚类螯合剂由HMO计算表明,它们的羟基氧原子的电荷密度qo_H、配键N原子的电荷密度q_N及pk_a值都发生明显的变化,它们与TRPO的协萃能力随配键强度的增加而上升,并随PK_a值的上升而下降,其中最合适的结构是1-OH-2-(C_6H_5N=N)-C_(10)H_6,它的Pk_a值较小,q_N适中,所以协萃能力最大。相反,1-(C_6H_5N=N)-8-OH-C_(10)H_6的q_N最小,pK_a居中,协萃能力最小;(3)螯合物的稳定性主要由配键控制。因此,以螯合物分子的内氢键强度Δδo_H来量度配键强度,发现螯合剂萃取锂的分配系数随其分子的Δδ_OH/pk_a值的增大而递增。     

HMO法在萃取剂的化学结构与性能研究中的应用

用Hukell分子轨道法(简称HMO法)对中性磷类、酸性磷类、β-双酮(包括羟基酮),羟肟类等化合物的结构与萃取性能的关系进行了研究。解HMO的高阶久期方程式用Jacobi法求实对称矩阵特征值及特征向量的标准程序。由此计算了电荷密度、最高占据轨道电荷密度(HOMO)、键序、轨道能级、原子间的π-键能、超离域性等结构参数。并讨论了化学结构与萃取性能的关系。一、中性磷化合物的萃取性能主要取决于磷酰氧原子的电荷密度、而后者与取代基团的极性     

某些有机磷化合物负离子电子轰击(NEI)质谱研究

本文应用低分辨负离子电子轰击质谱及亚稳分析数据,研究了12种有机磷化合物的负离子质谱特性,探讨了其碎裂规律。指出取代基的性质及其位置对分子异构化重排有显著的影响。     

有机磷化合物的研究 Ⅸ.某些具有活泼亚甲基化合物的碳磷酰化反应

本文报道对取代苯乙腈的碳阴离子和烯醇阴离子的磷酰化反应。前者可顺利地与磷酰氯生成碳膦酰化产物。某些β-双酮和β-酮酸酯的烯醇阴离子与二乙基磷酰氯的反应为区选性的氧磷酰化。这类反应特性与由EHMO法计算的结果一致。     

有机磷化合物的研究IX.某些具有活泼亚甲基化合物的碳磷酰化反应

The formation of P -- C bond is one of the important problems in synthetic organophosphorous chemistry. This paper describes the study of the formation of P -- C linkage via phosphorylation of carbon atom containing active hydrogen. p-Substituted phenylacetonitrile possessing an active methylene group undergoes stepwise C -- phosphorylation smoothly with diethyl phosphoryl chloride in the presence of naphthalene-sodium. Phosphonyl chloride reacts analogously. Being a deprotonizing agent naphthalene-sodium is distinguished by its availability, effectiveness and mild reaction conditions. The presence of an electron-withdrawing group in the benzene ring reduces the yield of phosphorylation seriously. The chemical shift of ^3^1P NMR of the resulted α-cyano-benzylphosphonates (1) correlates linearly with the Hammett \s\ constants of the substituents. As indicated by ^1H NMR studies the protons in the ester ethyl groups are magnetically nonequivalent. Compound 1 can be alkylated with alkyl halide or condensed with aromatic aldehyde by Hornor-Wittig type reaction due to the presence of active hydrogen atom. The structure-reactivity studies of diethyl phosphoryl chloride on reacting with various β- and β-diketones and β-keto esters (5) as regiospecific reaction were reported. The influences of metal ions in the enolates on the reactivity of the latter were examined and discussed. Only vinyl phosphates with predominantly Z configuration have been isolated exclusively. The C atom with an active hydrogen in the β-diketones investigated is inert to phosphorylation. These experimental results are well supported by reaction selectivity in terms of Eqo/Ecoc based on EHMO calculation.     

开链冠醚萃取铀氧离子性能的研究

研究了新萃取剂BQTH在三氯甲烷溶液中,从水杨酸根介质中萃取铀的性能,考察了水相酸度、萃取剂浓度、水杨酸根离子浓度及萃取时间对萃取效能的影响,确定了萃合物中萃取剂(BQTH)与UO2+2的组成比为1∶1及最佳萃取条件。在最佳条件下该萃取体系对1×10-4mol/L的铀酰离子一次萃取率可达78.0%.     

铀酰萃取剂双亚砜的合成及其微胶囊萃取铀性能的研究

铀是一种非常重要的能源物质 ,现在国际上一般使用磷酸三丁酯 (ＴＢＰ)作为铀的萃取剂提取及回收铀。ＴＢＰ对铀有较强的萃取能力 ,但它耐辐照能力较差 ,有关双亚砜的报道仅局限于ｎ =1 ,2 [1,2 ] 。本文以硝酸为氧化剂 ,采用硫醚氧化法 ,合成了四个新的双亚砜类化合物ＰｈＳＯ(ＣＨ2 ) ｎＳＯＰｈ(ｎ分别为 2、3、4、6) ,并经元素分析、核磁共振对其结构进行了表征。为避免萃取过程中乳化或三相的出现 ,采用界面缩聚法[3 ] 以高分子材料包覆ＴＢＰ和自制的双亚砜类化合物 (ｎ =2 ,4,6) ,制成微胶囊 ,对其在酸性水溶液 (ｐＨ =1～1 .5 )中萃…     

有机磷化合物的研究——Ⅸ.某些活泼亚甲基化合物的碳膦酰化反应

本文研究了一些活泼亚甲基化合物与膦酰氯的反应。 以萘钠为除质子试剂,苯乙腈和对取代苯乙腈用二乙基膦酰氯进行碳-膦酰化,比文献方法操作方便,条件温和,得率较高。     

有机磷化合物的研究 VIII. 酸性有机磷化合物的气相色谱

Acidic organophosphorus compounds may be identified by GLC via their methyl esters, usually prepared from diazomethane. The wide applications of this mthod are, however, limited by the toxicity of diazomethane. Tetramethyl ammonium hydroxide in methanol solution reacted rapidly with acidic organophosphorus compounds at room temperature to form tetramethyl ammonium salts, which were then converted to the corresponding methyl esters by pyrolysis at 300-350 deg.C. A simple and convenient method for separation and identification of various types of acidic phosphates, phosphonates and phosphinates by GLC has been developed. The GLC behaviours of phosphoric acid dialkyl esters, mono-esters of phenyl-and cyclohexyl-phosphonic acids as well as dialkylphosphinic acids can be represented by corrected retention time (t'R) which correlates linearly with the number of carbon atoms of the alkyl groups in these organophosphorus compounds. The influence of number of carbon atoms and isomerization of alkyl group on t'R values and retention index (I) calculated by Kovats equation was discussed. As shown by our experiments the change in retention index (ΔI) in the homologous series of phosphoric acid dialkyl esters is nearly a constant on lengthening the alkyl group of the esters with methylene linkages.     

苄基功能化离子液体对有机磷和苯环化合物的分散液-液微萃取性能研究

以苄基功能化的离子液体1-苄基-3-甲基咪唑双三氟甲烷磺酰亚胺(1-Benzyl-3-methylimidazolium bis [(trifluoromethyl)sulfonyl]imide,[BeMIM][Tf2 N])作为分散液-液微萃取的萃取剂,与高效液相色谱联用,用于环境水样中5种有机磷农药(辛硫磷、杀螟松、毒死蜱、甲拌磷和对硫磷)以及2种苯环化合物(氯化萘和蒽)的萃取与富集。并与其它离子液体([OMIM][Tf2 N])以及普通有机溶剂(CCl4和 C2 Cl4)的萃取效能进行了对比。萃取优化条件为：40μL [BeMIM][Tf2 N]作为萃取剂,1 mL 甲醇作为分散剂,离心时间5 min,样品溶液中不添加盐。在优化的条件下,本方法的线性关系良好(R2=0.9994~0.9998);对10,40和100μg/ L 不同添加浓度重复测定5次的日内和日间 RSD 分别为1.1%~4.3%和0.8%~4.8%,LOD 为0.01~1.0μg/ L (S/ N=3)。将本方法用于3种实际水样中目标分析物的测定,加标回收率和 RSD 分别为82.7%~118.3%和0.7%~5.6%。由于在咪唑环上引入了苄基基团,[BeMIM][Tf2 N]与目标分析物之间除存在疏水作用外,还存在π-π作用,故对目标物的萃取效率明显提高,富集倍数和回收率分别高达339和81.4%。测定了分析物在[BeMIM][Tf2 N]-DLLME 体系中的分配系数,对萃取机制进行初步探讨。     

有机磷化合物的研究 Ⅷ.酸性有机磷化合物的气相色谱

酸性磷(膦)酸酯与四甲基氢氧化铵的甲醇溶液反应制得的四甲基铵盐溶液,热解转化成O-甲基化产物用气相色谱鉴定。分离与鉴定了磷酸二烷基酯、磷酸单烷基酯、烷基膦酸单烷基酯和二烷基膦酸等,并讨论了烷基碳原子数和烷基的空间效应对校正保留时间(t′_R)及保留指数(I)的影响。     

饱和碳配体铀化合物的结构及成键性质研究

铀化物的合成已成为金属有机化学领域的研究热点之一。相比于过渡金属化合物,铀化物的合成与分离极具挑战性,尤其是包含铀碳键化合物。碳卡宾具有孤对电子易与铀的空轨道成键,而苄基或烷基中的碳无孤对电子,难以与铀结合,所以饱和碳配体铀化合物的研究较少。随着人们对铀独特的电子结构与成键性质的研究,基于饱和碳配体铀化合物研究取得了一些进展。本综述系统总结了饱和碳配体与不同价态的铀（+3、+4、+5和+6）形成化合物的结构以及成键性质。