Conventional strain energy in the oxadiazetidines
Conventional strain energy in the oxadiazetidines
复制标题
DOI：
10.1002/qua.20245
复制
发表时间：
2004-12-05
影响因子：
2.2
通讯作者：
Magers, DH
中科院分区：
文献类型：
--
作者：
Benton, CW;Magers, DH
对所有四种同分异构体的常规应变能是在等密度、同密度和高同密度模型中确定的。利用自洽场理论、二阶微扰理论和密度泛函理论（DFT），并采用两组三ζ价质量基集：6-311G（d,p）和6-311+G(2df,2pd)，计算了所有相关分子系统的最佳平衡几何形状、谐波振动频率和相应的电子能量。所采用的DFT泛函是使用Lee、Yang和Paar相关泛函的Becke三参数混合泛函。在二阶Moller-Plesset (MP2)/6-311G（d,p）和MV2/6-311+G（2df,2pd）优化几何结构下，还计算了采用更大基集的单点四阶微扰理论和耦合簇理论[CCSD(T)]，以确定高阶相关效应对应变能计算的影响，并衡量几何结构对这些效应的影响。用同样的模型和方法，计算了恶氮替丁两种异构体的常规应变能，以确定环中碳取代氮对应变能的影响。(C) 2004 Wiley期刊有限公司
The conventional strain energies for all four isomers of oxadiazetidine are determined within the isodesmic, homodesmotic, and hyperhomodesmotic models. Optimum equilibrium geometries, harmonic vibrational frequencies, and corresponding electronic energies are computed for all pertinent molecular systems using self-consistent field theory, second-order perturbation theory, and density functional theory (DFT) and employing two basis sets of triple-zeta valence quality: 6-311G(d,p) and 6-311+G(2df,2pd). The DFT functional employed is Becke's three-parameter hybrid functional using the Lee, Yang, and Paar correlation functional. Single-point fourth-order perturbation theory and coupled-cluster theory restricted to single and double excitations [CCSD(T)] calculations employing the larger basis set also are computed, at both the second-order Moller-Plesset (MP2)/6-311G(d,p) and the MV2/6-311+G(2df,2pd) optimized geometries, to determine the effect of higher-order correlation effects on strain energy computation and to gauge the effect of geometry on these effects. Using the same models and methods, the conventional strain energies for both isomers of oxazetidine also are computed, to determine the effect on the strain energy of replacing a nitrogen with a carbon in the ring. (C) 2004 Wiley Periodicals, Inc.