氢化物中A-H键物理化学性质递变规律的研究Ⅴ.A-H键酸性强度PK_a的计算  

STUDY ON THE PHYSICAL AND CHEMICAL PROPERTIES OFA-H BOND IN HYDRIDE V. CALCULATION OF ACIDITY PK_a?OF A-H BONDS

作　　者：余训民 杭义萍 毛明现 

机构地区：[1]广西梧州师专化学系

出　　处：《荆州师专学报》1997年第5期78-81,共4页

摘　　要：根据Randic的分子连通性拓扑方法 ,提出了一个新的分子拓扑指数Y ,将P区氢化物PKa 与分子拓扑指数Y相关联 ,复相关系数为 0 .9991 ,标准偏差为 1 .0 1 ,其计算公式为 :PKa =34 .94Y +32 .0 3(1 -q)r- 1 A -H- 4 4 .53 .式中rA -H 为氢化物 (HnA—H)分子中A-H键键长 ,q为氢化物所带电荷数 .对近 2 0个P区氢化物分子的酸性强度PKa 进行了计算 ,理论值与实验值符合程度高 ,平均偏差为 0 .53 。On the basis of Randic's molecular connectivity index, a new topological index Y is proposed.In this work,a linear regeession equation of the relationship between acidity PK a?and topological index Y of hydrides is obtained: PK a=34.94+32.03(1-q)r -1 A-H —44.53(R=0.9991,S a=1.01) Where r ? A-H and q are the A-H bond length and the charge of the hydrides,individually.The  PK a  of 20 hydride are calculated by the equation. The results calculated show that the predicted values agree with the experimental values satisfactorily.

关 键 词：分子拓扑指数 氢化物 酸性强度 结构与性能 物理化学性质 

分 类 号：O641.1[理学—物理化学]