Udagawa Taro, Tachikawa Masanori
Quantum Chemistry Division, Graduate School of Science, Yokohama City University, Seto 22-2, Kanazawa-ku, Yokohama 236-0027, Japan.
J Chem Phys. 2006 Dec 28;125(24):244105. doi: 10.1063/1.2403857.
To analyze the H/D isotope effect on porphine and porphycene molecules including the protonic/deuteronic quantum nature and electron correlation efficiently, the authors have developed the new scheme of the multicomponent hybrid density functional theory [MC_(HF+DFT)]. The optimized geometries of porphine, porphycene, and these deuterated isotopomers by our MC_(HF+DFT) method are in good agreement with the experimental "high-symmetric" structures, contrary to the "low-symmetric" geometries optimized by pure multicomponent Hartree-Fock method. The optimized geometries for HD-porphine and HD-porphycene molecules, in which an inner hydrogen is replaced to a deuterium, are found to be low symmetric. Such drastic geometrical change induces the electronic polarization, and gives rise to the slight dipole moment values in these HD species. Their results clearly indicate that the difference of the nuclear quantum nature between inner proton and inner deuteron directly influences the molecular geometry and electronic structure.
为了有效分析卟吩和卟啉分子上的氢/氘同位素效应，包括质子/氘核的量子性质和电子相关性，作者们开发了多组分混合密度泛函理论的新方案[MC_(HF+DFT)]。通过我们的MC_(HF+DFT)方法得到的卟吩、卟啉及其氘代同位素异构体的优化几何结构与实验“高对称”结构吻合良好，这与通过纯多组分Hartree-Fock方法优化得到的“低对称”几何结构相反。发现内氢被氘取代的HD-卟吩和HD-卟啉分子的优化几何结构是低对称的。这种剧烈的几何变化会引起电子极化，并在这些HD物种中产生轻微的偶极矩值。他们的结果清楚地表明，内质子和内氘核之间核量子性质的差异直接影响分子几何结构和电子结构。
