Department of Chemistry, Syracuse University, 1-014 Center for Science and Technology, Syracuse, New York 13244-4100, USA.
Chemphyschem. 2011 Jun 6;12(8):1542-9. doi: 10.1002/cphc.201100050. Epub 2011 May 3.
Spectral comparison is an important part of the assignment of the absolute configuration (AC) by vibrational circular dichroism (VCD), or equally by Raman optical activity (ROA). In order to avoid bias caused by personal interpretation, numerical methods have been developed to compare measured and calculated spectra. Using a neighbourhood similarity measure, the agreement between a computed and measured VCD or ROA spectrum is expressed numerically to introduce a novel confidence level measure. This allows users of vibrational optical activity (VOA) techniques (VCD and ROA) to assess the reliability of their assignment of the AC of a compound. To that end, a database of successful AC determinations is compiled along with neighbourhood similarity values between the experimental spectrum and computed spectra for both enantiomers. For any new AC determination, the neighbourhood similarities between the experimental spectrum and the computed spectra for both enantiomers are projected on the database allowing an interpretation of the reliability of their assignment.
光谱比较是通过振动圆二色性（VCD）或同等的拉曼光学活性（ROA）确定绝对构型（AC）的重要组成部分。为了避免因个人解释而产生的偏差，已经开发出了数值方法来比较实测光谱和计算光谱。使用邻域相似性度量，将计算出的 VCD 或 ROA 光谱与实测光谱之间的一致性数值化，以引入新的置信度度量。这允许振动光学活性（VOA）技术（VCD 和 ROA）的使用者评估其化合物 AC 分配的可靠性。为此，编译了一个成功的 AC 确定数据库，以及实验光谱与两种对映体的计算光谱之间的邻域相似性值。对于任何新的 AC 确定，实验光谱与两种对映体的计算光谱之间的邻域相似性值都将被投影到数据库上，从而可以解释其分配的可靠性。
