The Application Of Two-Dimensional Asynchronous Spectra Based On Asynchronous Orthogonal Sample Design Scheme In Probing Intermolecular Interactions

Intermolecular interactions have been the focus of extensive researches and, as they play an mportant role in understanding the mechanisms of many chemical, physical, and biological processes, such as assembly of supra-molecular architectures, molecular recognition, and nolecular catalysis. Most intermolecular interactions can induce only subtle spectral changes hat are hardly detected by conventional measures. Therefore, determining how to evaluate such nteractions effectively is still a baffling question.This paper introduces a new approach called asynchronous orthogonal sample design cheme (AOSD), by taking the concentrations as the perturbation and based on the wo-dimensional correlational analysis and orthogonal vectors. The interfering portion arising trictly from concentration effect can be completely removed from the asynchronous spectra by sing the AOSD approach. Thus,2D asynchronous spectra can be used as an effective tool to haracterize intermolecular interactions. A model system is adopted to verify the validity of the (?)OSD approach and the behaviors of the 2D asynchronous spectra under different overlapping xtent of the characteristic peaks are investigated. Simulation results demonstrate that the esultant spectral patterns can reflect subtle spectral variation in bandwidths, peak positions, and bsorptivities brought about by intermolecular interaction, which are hardly visualized in the onventional 1D spectra. Furthermore a real system is employed to prove the applicability of the (?)OSD method. Based on the model and realistic experiments, we can obtain that the AOSD pproach is an advantageous tool even if the characteristic peaks of two compounds are abstantially overlapped and the corresponding experiments can be achieved only by general istruments such as IR and UV.Finally the number of mixed solutions at least needed and whether adding numbers of the (?)ixed solutions or the changes of sequence of the 1D spectra will affect the intensity of the D asynchronous spectra are discussed.