在过渡金属复合体中有多少电子捐赠? 一个计算研究
Augustine Obeng1, Jochen Autschbach1
1Department of Chemistry, University at Buffalo State University of New York Buffalo, New York 14260-3000, United States.
Journal of chemical theory and computation
|June 10, 2024
概括
本研究评估了用于准确描述金属复合体中dative结合的计算方法. 某些密度函数和合集群模型显示出对量化金属-联体电子捐赠的前景.
科学领域:
- 计算化学计算化学
- 量子化学 是一个量子化学.
- 协调化学 协调化学
背景情况:
- 源性共价相互作用 (金属对配体和配体对金属的捐赠) 在协调化学中至关重要.
- 这些相互作用中的电子移位对近似计算方法具有挑战性.
- 准确描述dative结合对于理解化学反应性和特性至关重要.
研究的目的:
- 评估各种计算方法在关闭外过渡金属复合体中量化dative结合的准确性.
- 确定可靠的理论方法来描述金属连接体电子捐赠.
- 为了比较不同密度函数和后哈特里-福克方法的性能.
主要方法:
- 评估Kohn-Sham密度函数在不同的近似"阶段".
- 评估后哈特里-福克方法,包括MP2和合集群模型.
- 与合集群单个和双重与扰动性三重 (CCSD(T)) 基准方法进行基准测试.
主要成果:
- 非混合和全球混合功能 (例如,B3LYP,PBE0) 经常高估dative捐赠.
- 全球混合体具有更高的精确交换率 (40-50%) 和CAM-B3LYP显示了更好的准确性.
- 双混合功能提供令人满意的结果,纠正MP2错误.
- DLPNO-CCSD提供了一个合理的,虽然稍微低估,捐赠的描述.
结论:
- 计算方法的选择显著影响了dative结合描述的准确性.
- 分隔范围和双混合函数,以及近似合集群方法,代表了准确的dative相互作用计算的有希望的途径.
- 为了精确量化协调复合体中的电子捐赠,需要进一步完善计算模型.
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