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1.
无机氢化物的pKa与mQ的关系   总被引:20,自引:0,他引:20  
元素的周期数连接性指数(mQ)的0Q、1Q定义为:0Q=∑(ni)-0.5,1Q=∑(ni·nj)-0.5.0Q与1Q均对13种p区氢化物呈现唯一性表征,并与其酸性强度pKa的相关系数为:0.9587、0.9919,引入nd的三元相关系数为0.9951.对pKa的预测结果优于文献方法.  相似文献   

2.
定义原子特征值βi=(ni-1)mi±hi.由βi建构新的价连接性指数mX=∑(βi·βi·βk…)0.5,其中0阶指数0X=∑(βi)0.5,1阶指数1X=∑(βi·βi)0.5.并计算了4个系列72个烃分子的0X、1X值.发现mX与烃的标准熵、标准燃烧热有良好的相关性,相关系数均在0.99以上.并采用Jackknife方法对模型稳健性进行了检验.  相似文献   

3.
离子极化力连接性拓扑指数的应用   总被引:4,自引:0,他引:4  
唐自强 《化学通报》2003,66(5):351-356
本文提出离子极化力连接性拓扑指数,定义为:mX=∑(gixgi……)^-0.5,gi为原子的极化力值,其0、1阶指数公式分别为:0X=∑(gixgj)^-0.5,0X,1X与56种金属卤化物的晶格能(U)呈优级线性关系,回归方程为:U=-631.58 1061.65^oX 1719.59^1X r=0.9996,另外,0X,1X与碱金属卤化物的磁化率,M-X键长等亦显著相关。  相似文献   

4.
堵锡华  冯长君 《分析化学》2001,29(3):330-332
在邻接矩阵的基础上,建立化合物的主量子数拓扑指数mX:0X=Σ(δi)0.5,1X =Σ(δi*δj)0.5,并计算了13个系列94个分子的0X、1X值。发现0X或1X与这些化合物的气相色谱保留指数RI有很好的相关性。相关系数均在0.97以上,略优于文献方法。并且物理意义明确,计算简单,使用方便。  相似文献   

5.
提出了计算有机物分子中成键原子点价δzi的新方法,以δzi为核心建构了一个新的分子连接性指数mXz(m=0,1),并探讨了mXz指数与烷基苯标准生成焓-△fH()m的相关性,结果表明,mXz指数对于烷基苯具有良好的结构选择性和性质相关性.以0Xz,1Xz和碳原子数Ⅳ为自变量的三元线性回归方程为-△fH()m=58.008 0Xz+27.075 1Xz+929.836N-1504.311,该方程对烷基苯标准生成焓的预测结果令人满意.  相似文献   

6.
价电子平均能级连接性指数及其应用   总被引:1,自引:0,他引:1  
定义价电子平均能级(δi)为:δi=(ni-1)(ni+ΣEij)0.5/(1+mi)。由δi建构分子连接性指数(mQ),其中,0Q=Σ(δi)-0.5、1Q=Σ(δiδj)-0.5。0Q与无机物总键能ΔE、0Q2与过渡元素卤化物的ΔfHmθ、1Q0.5与碱金属卤化物晶格能U、0Q及1Q与无机氢化物pKa的相关系数分别为0.9734、0.9769、0.9906、0.9945,均优于文献方法。mQ是一种结构选择性、性质相关性俱佳的拓扑指数。  相似文献   

7.
用原子特性自相关拓扑指数预测链烷烃的热力学性质   总被引:3,自引:0,他引:3  
原子特征值 ( Si)被定义为 :Si=ni- 1ki mi( ∑Eij+ hi Ei)。由 Si建构原子特征自相关拓扑指数 ( F )及原子特征连接性指数 ( Y)的公式为 :F =∑( Si· Sj) 0 .5、Y=∑ ( Si·Sj) - 0 .5。它们与 85种链烷烃热力学性质 ( P)的二元线性回归方程为 :P =a + b F +c Y(或 P3) 。 P为标准生成焓、标准熵、标准生成自由能的二元相关指数依次为 0 .9953、0 .9992、0 .9941 ,优于文献方法  相似文献   

8.
在邻接矩阵的基础上,建立一种新的拓扑指数mT,mY=∑(δi·δj·δk…)0.5,其中0T=∑(δi)0.5,1Y=∑(δi·δj)0.5,并计算了10个系列142个分子的0T,1T值.发现mT与这些化合物的气相色谱相对物质的量校正因子有很好的相关性.相关系数均大于0.96,拓扑指数mT能较好地反映化合物的结构特征.  相似文献   

9.
分子连接性指数(mZh)与烷基苯理化性质的相关性研究   总被引:1,自引:0,他引:1  
定义有机物分子中成键原子点价δiz.基于δiz和分子图的邻接矩阵,建构一种新的分子连接性指数mZh(m=0,1),并研究了0Zh,1Zh与烷基苯的燃烧热、等张比容、沸点、汽化热、标准生成自由能、标准熵、摩尔体积、溶解度、正辛醇/水分配系数等10种物理化学性质的相关性.结果表明:0Zh,1Zh与烷基苯的物理化学性质具有优良的性质相关性,二元相关系数均在0.99以上;以0Zh,1Zh和分子中C原子数NC为自变量的三元线性回归方程对烷基苯理化性质的预测结果相当令人满意.  相似文献   

10.
利用紫外光谱、荧光光谱、1H NMR等技术研究七元瓜环(Q[7])、八元瓜环(Q[8])与盐酸他克林(THA)的主-客体包合作用及pH敏感释药性能。测得Q[7]-THA、Q[8]-THA体系作用的包合比分别为2∶1和1∶1、包合平衡常数分别为1. 85×10~4L·mol~(-1)和1. 98×10~4L·mol~(-1)。在pH=1. 2、pH=4. 0、pH=6. 8介质中,包合物Q[7]-THA的400min体外累积释放分别为49. 58%、53. 80%、56. 48%,包合物Q[8]-THA的体外累积释放分别为46. 11%、47. 40%、51. 49%,THA原药的体外累积释放分别为99. 33%、98. 41%、96. 87%。结果表明Q[7]及Q[8]的包合对THA有明显的pH敏感性缓释作用。  相似文献   

11.
A new and simple synthesis of novel N-protected methyl 5-substituted-4-hydroxypyrrole-3-carboxylates, which exist in equilibrium with their 4-oxo tautomers, has been developed in two steps starting from N-protected α-amino acids. The key intermediates are enaminones, which can also be isolated, characterized, and used for the construction of other functionalized heterocycles, before they spontaneously decompose to pyrrole products. 4-Hydroxypyrroles are prone to partial aerial oxidation but can be efficiently alkylated or reduced to stable polysubstituted pyrrolidine derivatives.  相似文献   

12.
The chemoselectivity in the intramolecular CH insertion of various diazosulfonamides has been experimentally studied. The results reveal that the aliphatic 1,4-, 1,5-, or 1,6-C(sp3)?H insertions of diazosulfonamides are not accessible, while the aromatic 1,5-C(sp2)?H insertion can be realized specifically by adjusting the diazo-adjacent group. In addition, the general chemoselectivities in the intramolecular CH insertions of diazosulfonyl compounds are summarized. Generally, diazosulfones undergo both aromatic 1,5-C(sp2)?H and aliphatic 1,5- and 1,6-C(sp3)?H insertions, while diazosulfonates undergo aliphatic 1,5- and 1,6-C(sp3)?H insertions. However, diazosulfonamides only undergo aromatic 1,5-C(sp2)?H insertion.  相似文献   

13.
N-Heterocyclic carbene-palladacyclic complexes 3 were successfully achieved in a one-pot procedure under mild conditions. The structure of 3a was unambiguously confirmed by X-ray single crystal diffraction and it was an active catalyst in the Buchwald-Hartwig amination and α-arylation of ketones even at very low catalyst loadings (0.01?mol%).  相似文献   

14.
An efficient iodine-mediated oxidative Pictet-Spengler reaction in dimethyl sulphoxide (DMSO) using terminal alkynes as the 2-oxoaldehyde surrogate for the synthesis of aryl (9H-pyrido[3,4-b]indol-1-yl)methanones is described. The scope of the protocol includes the total synthesis of Fascaplysin, Eudistomins Y1 and Y2. The methodology is extended for preparing pyrrolo[1,2-a]-quinoxaline and indolo[1,5-a]quinoxaline derivatives. The utility of 1-aroyl-β-carbolines was demonstrated by performing palladium-catalyzed β-carboline directed ortho-C(sp2)-H functionalization of the phenyl ring with thiomethyl (SMe) group using DMSO as source and for accessing 4-aryl-canthin-6-ones.  相似文献   

15.
In this Letter, we described a facile method for constructing fused bicyclic 1-arylpyrazol-5-one ring system. We employed various methylene-containing carboxylic acids as the substrates and proved that the pyrazolone ring closure requires activated methylene group in intermediate II. Accordingly, a series of structurally diversified, fused bicyclic 1-arylpyrazol-5-ones was prepared in moderate to high yields using the requisite substrates.  相似文献   

16.
Synthesis of substituted pyrrolo[1,2-a]pyrazines and pyrazino[1,2-a]indoles from the Morita-Baylis-Hillman derivatives of acrylates via saponification followed by Curtius reaction is described.  相似文献   

17.
用正丁胺作为碳源,采用射频辉光放电制备碳膜,选用激光染料R6G和聚乙二醇混合液作为蒸气源,采用单源热蒸发,在蒸发室与染料同时沉积得到混合膜,用拉曼光谱和红外光谱分析了碳膜的结构和键合方式,分析表明:碳膜中存在胺基团和氢原子.混合膜的荧光谱测量结果表明,认为正丁胺对染料荧光谱的影响是因为胺基和氢原子的存在.  相似文献   

18.
19.
A series of 20 CuAIAC reactions between eight 4-acylamino substituted pyrazolidine-3-one-1-azomethine imines and four terminal ynones were performed using Cu0 as catalyst. The corresponding fluorescent cycloadducts were obtained in very high yields upon simple workup. Thus, Cu-metal turned out to be a better catalyst than CuI in terms of yield and ease of isolation. Availability of azomethine imines, mild reaction conditions, and simple workup enable a “click” access to libraries of densely substituted 2,3-dihydro-1H,5H-pyrazolo[1,2-a]pyrazol-1-ones. Reactivity of differently substituted dipoles was evaluated experimentally and by quantum chemical methods (DFT).  相似文献   

20.
(E)-4-(Fullerenopyrrolidin-1-yl)-3-methylbut-2-enoic acid and its corresponding succinimidyl ester, readily obtained through Prato-type modification of C60, were used for the selective N-acylation of polyamines. The thus obtained conjugates were evaluated for their antioxidative and anti-inflammatory activity and their cytotoxicity was determined. Members of this family of compounds showed interesting anti-lipid peroxidation, anti-lipoxygenase and anti-inflammatory activity and comparable cytocompatibility to spermidine.  相似文献   

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