乳清酸的DFT和红外光谱研究(英文)

Density functional theory and infrared studies on the orotic acid

乳清酸是配位化学中的一种良好配体．它的酮式和烯醇式互变异构体，以及不对称结构，使其成为多用途的多齿有机配体．为充分理解其空间构型、异构化过程以及获得一些有用的参数，使用Gaussian98程序包在B3LYP／6-311＋G^＊基组水平上优化TSL清酸的结构，发现1a是能量上最稳定的构型．计算结果显示，空间效应、氢键和共轭相应在维持其特定结构中发挥了重要作用．对质子转移过程的研究表明，质子转移的能垒相对较高，而顺反异构的能垒相对较高．取光谱可以帮助我们区别不同乳清酸异构体，并识别光谱实验的谱图．

Orotic acid is a good organic building block in coordination chemistry. Its ketonic and enolic tautomers, along with its asymmetric geometry, make it a versatile multidentate organic ligand. Some structures of the orotic acid were optimized with Gaussian 98 program package at B3LYP/6-311 ＋G^＊ level to fully understand its spatial configurations, isomerization processes, and to obtain some useful parameters. Our calculations show that the steric effect, hydrogen bonding and conjugative effect play an important role in keeping certain configurations, and la is the most stable one in energy. The investigation on the proton-transfer processes shows that the energy barriers of proton transfer processes are relatively high, but the energy barriers of the cis-trans isomerization of hydrogen atoms are relatively low. The IR spectra can help us identify different isomers and the vibrational modes in spectrum experiments.