Department of Chemistry and Biochemistry, University of California San Diego, San Diego, California 92093, United States.
J Phys Chem B. 2023 May 18;127(19):4268-4276. doi: 10.1021/acs.jpcb.2c07565. Epub 2023 May 9.
Ultrafast molecular dynamics are frequently extracted from two-dimensional (2D) spectra via the center line slope (CLS) method. The CLS method depends on the accurate determination of frequencies where the 2D signal is at a maximum, and multiple approaches exist for the determination of that maximum. Various versions of peak fitting for CLS analyses have been utilized; however, the impact of peak fitting on the accuracy and precision of the CLS method has not been reported in detail. Here, we evaluate several versions of CLS analyses using both simulated and experimental 2D spectra. The CLS method was found to be significantly more robust when fits were used to extract the maxima, particularly fitting methods that utilize pairs of opposite-sign peaks. However, we also observed that pairs of opposite-signed peaks required more assumptions than single peaks, which are important to check when interpreting experimental spectra using peak pairs.
超快分子动力学通常通过中心线斜率（CLS）方法从二维（2D）光谱中提取。CLS 方法取决于准确确定 2D 信号达到最大值的频率，并且存在多种方法来确定该最大值。已经使用了各种版本的峰拟合来进行 CLS 分析；但是，峰拟合对 CLS 方法的准确性和精密度的影响尚未详细报道。在这里，我们使用模拟和实验 2D 光谱评估了几种版本的 CLS 分析。当使用拟合来提取最大值时，CLS 方法发现明显更稳健，特别是使用一对相反符号的峰进行拟合的方法。但是，我们还观察到，与单个峰相比，一对相反符号的峰需要更多的假设，这在使用峰对解释实验光谱时很重要。
