Determination of the Absolute Configurations Using Exciton Chirality Method for Vibrational Circular Dichroism: Right Answers for the Wrong Reasons?
Determination of the Absolute Configurations Using Exciton Chirality Method for Vibrational Circular Dichroism: Right Answers for the Wrong Reasons?
复制标题
使用激子手性方法确定振动圆二色性的绝对构型：错误原因的正确答案？
DOI：
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发表时间：
2015
影响因子：
2.9
通讯作者：
P. Polavarapu
中科院分区：
文献类型：
--
作者：
C. Covington;V. P. Nicu;P. Polavarapu
给出了3-苯甲酰基樟脑酮型和螺酰二乙酸酯A和B构象柔性二乙酸酯的振动圆二色性（VCD）谱的量子化学预测。简要回顾了激子手性模型，并提出了一种评估激子手性模型相关性的方法。QC结果与文献实验VCD光谱以及用EC模型得到的VCD光谱进行了比较。这些比较表明，EC对与苯甲酰樟脑、双乙酸螺虫酰胺A和双乙酸螺虫酰胺B的C = O拉伸振动相关的双ignate VCD偶联的贡献分别仅为~ 30%、~ 3%和~ 15%。由于EC的贡献如此之小，文献中使用EC概念提出的双乙酸螺虫酰A和双乙酸螺虫酰B分子的正确绝对构型（ACs）可以被认为是偶然的。确定了使用VCD的EC概念获得错误AC预测的可能性，并提出了该模型未来使用的指导方针。
Quantum chemical (QC) predictions of vibrational circular dichroism (VCD) spectra for the keto form of 3-benzoylcamphor and conformationally flexible diacetates of spiroindicumide A and B are presented. The exciton chirality (EC) model has been briefly reviewed, and a procedure to evaluate the relevance of the EC model has been presented. The QC results are compared with literature experimental VCD spectra as well as with those obtained using the EC model for VCD. These comparisons reveal that the EC contributions to bisignate VCD couplets associated with the C═O stretching vibrations of benzoylcamphor, spiroindicumide A diacetate, and spiroindicumide B diacetate are only ∼30%, ∼3%, and ∼15%, respectively. With such meager EC contributions, the correct absolute configurations (ACs) suggested in the literature for spiroindicumide A diacetate and spiroindicumide B diacetate molecules using the EC concepts can be considered fortuitous. The possibilities for obtaining wrong AC predictions using the EC concepts for VCD are identified, and guidelines for the future use of this model are presented.
原型肽构象的实验和计算红外 CD 研究。
影响因子：
2.9
作者：
Birke,SS;Agbaje,I;Diem,M
通讯作者：
Diem,M