对氨基苯甲酸同系物的酸性、氧化性及分子稳定性的理论计算

采用量子化学HF/631G（d） 方法优化了对氨基苯甲酸及其同系物的几何构型,并在相同基组下采用MP2方法进行单点能的计算,讨论了对氨基苯甲酸及其同系物的酸性、氧化性及其分子稳定性.结果表明：对氨基苯甲酸同系物随着与羟基相连的碳链的增长,其酸性先减小后增大,前线分子轨道能级差逐渐减小,氧化性逐渐增强,且每增加1个-CH2-基团对物质稳定性的影响几乎是相同的;在相同骨架中随着给电子取代基的引入,其酸性差不多都是逐渐减小的,前线分子轨道的能级差逐渐减小,氧化性逐渐增强,且其一取代产物要比二取代产物稳定.

Theoretical studies on acidity, oxidizing property and molecular stability of p-aminomethylbenzoic acid and its homologous compound

Using quantum chemistry HF and MP2 methods, the acidity, oxidizing property and molecular stability of p - aminomethylbenzoic acid and its homologous compound has been calculated. The results indicate that with the increase of the length of carbon chain, which is combined with hydroxyl group, the acid increases first and then decreases while the energy gap of the frontier molecular orbital decreases, oxidizing property increase,and increasing every--CH2-- has most the same effects for molecular stability. And the substituent effects were also discussed. In the same backbone, with increasing the electron- donor substituent, its acid almost decreases, while the energy gap of the frontier molecular orbital decreases, its oxidizing property increases and its one substitutional production is more stable than its two substitutional productions.