顶向宏观测量的自下而上的原子描述:哈梅特电子参数的计算基准
Guilian Luchini1, Robert S Paton1
1Department of Chemistry, Colorado State University, 1301 Center Ave., Ft. Collins, Colorado 80523-1872, United States.
ACS physical chemistry Au
|May 27, 2024
概括
计算方法可以预测化学反应的电子效应,但原子选择显著影响准确性. 基于密度的方案,如希什菲尔德电荷,使用附着的原子,为哈梅特参数提供最稳定和可靠的预测.
科学领域:
- 物理有机化学 有机化学
- 计算化学计算化学
背景情况:
- 与化学反应性相关的电子效应是物理有机化学的基础.
- 线性自由能量关系 (LFER) 对于理解反应性至关重要.
- 计算方法为各种系统提供快速的电子参数预测.
研究的目的:
- 为预测电子参数进行计算收费方案的基准测试.
- 评估原子选择对描述器准确性的影响.
- 将计算预测与实证哈梅特参数进行比较.
主要方法:
- 检查了各种计算电荷方案 (量子力学,合适,半经验).
- 与实证哈梅特参数和实验速率差异相关联的计算描述符.
- 研究了原子位置 (环与附着原子) 对描述器性能的影响.
主要成果:
- 原子选择显著影响描述器的准确性,往往超过理论的计算水平.
- 对元替代剂 (σm) 的预测通常比对子替代剂 (σp) 差.
- 基于密度的方案 (例如,希尔什菲尔德收费) 显示出比人口分析方法更高的稳定性和性能.
- 使用附加的原子进行描述器计算,改善了统计相关性.
结论:
- 为计算电子描述器选择原子对于准确的反应性预测至关重要.
- 基于密度的方案和附加的原子计算提供可靠的哈梅特参数预测.
- 开发了一般的线性关系,以计算预测实验哈梅特参数.
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