On the mechanism of decomposition of dithiocarbamates
On the mechanism of decomposition of dithiocarbamates
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二硫代氨基甲酸盐的分解机理研究
DOI：
10.1021/j100699a033
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发表时间：
1970
期刊：
影响因子：
--
通讯作者：
C. L. Chakrabarti
中科院分区：
文献类型：
--
作者：
S. J. Joris;K. Aspila;C. L. Chakrabarti
二硫代氨基甲酸酯的滴定和分解动力学表明，二硫代氨基甲酸酯(DTC)酸分子的硫和氮原子之间存在分子内氢键。当二硫代氨基甲酸盐离子的硫原子质子化时，分子内氢键就形成了。分子内氢键产生的分数电荷在DTC酸中引入了很高的内能，这是导致DTC酸极不稳定的原因。DTC酸在混合溶剂中的分解动力学证明了这一点，这也揭示了DTC酸的溶剂化和相关稳定性存在较大的空间效应。DTC酸在混合溶剂中的特定溶剂化也被检测到。研究还表明，用于分解的活化络合物不可能与二硫代氨基甲酸酯的酸形式有很大的不同。
The titration of the dithiocarbamates and the kinetics of their decomposition indicate that an intramolecular hydrogen bond exists between the sulfur and the nitrogen atoms of the dithiocarbamic (DTC) acid molecule. This intramolecular hydrogen bond is formed as soon as the sulfur atom of the dithiocarbamate ion protonates. The fractional charges resulting from the intramolecular hydrogen bond introduce a high internal energy in the DTC acids and are responsible for their great instability. This is proven by the kinetics of decomposition in mixed solvents, which also revealsthe existence of a large steric effect on the solvation and on the related sta-bility of the DTC acids. Specific solvation of the DTC acids was also detectedin mixed solvents. It is also shown that the activated complex for decomposition cannot be very different from the acid form of the dithio-carbamates.