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由于湿法冶金的需要,络合物的力能特性及其与键合特性的关系正日益受到重视。为了总结络合物的热化学规律,我们以导出的键参量△E为基础,为所有元素设计了一套半经验指数Y~△,可称之为电荷迁移的热效应指数:Y_M~△=3.5f_Mf_H(R_H Z_M~*~(1/2)—R_M Z_H~*~(1/2)/R_MR_H(R_M+R_H)~(1/2) +1.3g(1)式中,f_M和f_H是M—H键中M和H原子的价层轨道成键能力,Z_M~*和R_M分别是相应原子的有效核电荷和共价半径,g是常数,对于外层电子结构为:s~(1-2),d~(1-10)(或f~(1-14)),p~(1-3),p~4,p~5,和p~6的元素,g值依次为:2,3,4,5,6和6.5。在式(1)的设计中注意到使下述关系近似成立: (Y_B~△—Y_A~△)~2=-△H_(AB)~O (2)△H_(AB)~O是键A—B的克键生成热(千卡/克键)。按式(1)算得各元素的荷移热指数Y△列于表1。
Due to the needs of hydrometallurgy, the force and energy properties of complexes and their relationship with the bonding properties are receiving more and more attention. In order to summarize the thermochemical laws of the complexes, based on the derived bond parameter ΔE, we design a set of semiempirical exponent Y ~ △ for all the elements, which can be called the thermal effect index of charge transfer: Y_M ~ △ = 3.5 f_Mf_H (R_H Z_M ~ * ~ (1/2) -R_M Z_H ~ * ~ (1/2) / R_MR_H (R_M + R_H) ~ (1/2) + 1.3g where f_M and f_H are M - H bond in the valence orbit bonding ability of M and H atoms, Z_M ~ * and R_M are the effective nuclear charges and covalent radii of the corresponding atoms, respectively, g is a constant, for the outer electron structure: s ~ (1- 2, d ~ (1-10) (or f ~ (1-14)), p ~ (1-3), p ~ 4, p ~ 5 and p ~ , 3, 4, 5, 6 and 6.5. It is noted in the design of equation (1) that the following relation holds approximately: (Y_B ~ △ -Y_A ~ △) ~ 2 = - △ H_ (AB) ) △ H_ (AB) ~ O is the bond formation heat (kcal / g bond) of bond A-B. The charge-transfer heat index YΔ of each element is calculated according to formula (1)