Assessment of theoretical methods for the calculation of methyl cation affinities
Assessment of theoretical methods for the calculation of methyl cation affinities
复制标题
甲基阳离子亲和力计算理论方法的评估
DOI：
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发表时间：
2008
影响因子：
3
通讯作者：
H. Zipse
中科院分区：
文献类型：
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作者：
Yin Wei;Thomas Singer;H. Mayr;G. N. Sastry;H. Zipse
各种中性和阴离子碱的甲基阳离子亲和力（MCA; 298 K）已经用各种各样的理论方法进行了计算研究。其中包括W1、G3、G3B3和G2等高级复合程序，CCSD(T)和MP2等传统从头算方法，以及密度泛函理论（DFT）方法的选择。几乎所有这些方法都可以很好地再现各种小模型系统的实验结果，并且基于DFT的方法的性能远远优于它们在这些小模型上的MP2类似物。对于较大的模型，包括有机催化剂中经常遇到的基序的体系，DFT方法的性能有所下降，而MP2方法的性能显著提高，使得前者方法对常见的有机碱不可靠。因此，MP2计算与6‐31+G（2d, p）或更大的基集相结合，似乎提供了一种实用可靠的方法来计算有机碱的MCAs。©2007 Wiley期刊公司计算机学报，2008
The methyl cation affinity (MCA; 298 K) of a variety of neutral and anionic bases has been examined computationally with a wide variety of theoretical methods. These include high‐level composite procedures such as W1, G3, G3B3, and G2, conventional ab initio methods such as CCSD(T) and MP2, as well as a selection of density functional theory (DFT) methods. Experimental results for a variety of small model systems are well reproduced with practically all these methods, and the performance of DFT based methods are far superior in comparison to their MP2 analogs for these small models. For larger model, systems including motifs frequently encountered in organocatalysts, the performance deteriorates somewhat for DFT methods, while it improves significantly for MP2, rendering the former methods unreliable for common organic bases. Thus, MP2 calculations performed in combination with basis sets such as 6‐31+G(2d, p) or larger, appear to offer a practical and reliable approach to compute MCAs of organic bases. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2008