The Estimation Of The Number Of Reactions In Chemical Systems Based On Orthogonal Sample Design Scheme

Intermolecular interactions have been the focus of extensive researches, they play an important role in understanding the mechanisms of many chemical, physical, and biological processes. Most intermolecular interactions can induce only subtle spectral changes that are hardly detected by conventional measures. Therefore, We need to study the suitable methods to detect the intermolecular interactions.One of the most attractive features in the 2D correlated spectroscopy is that the appearance of a cross peak in 2D synchronous spectra suggests the potential for investigating intermolecular interactions. In this article a new concentration series is proposed to construct 2D synchronous spectrum in orthogonal sample design(OSD) analysis to probe intermolecular interaction between solutes dissolved in the same solutions.The obtained 2D synchronous spectrum possesses the following two properties:(1) cross peaks in the 2D synchronous spectra can be used to reflect intermolecular interaction reliably since interference portions that has nothing to do with intermolecular interaction are completely removed;(2) the produced two dimensional synchronous spectrum can effectively avoid the accidental collinearity. Hence correct number of nonzero eigenvalues can be obtained so that the number of chemical reaction can be estimated. In real chemical system, noise present in 1D spectra may also produce nonzero eigenvalues. To get correct number of chemical reaction, we classified nonzero eigenvalues into significant nonzero eigenvalues and insignificant nonzero eigenvalue. Significant nonzero eigenvalues can be identified by inspecting of the pattern of the corresponding eigenvector with help of the Durbin-Watson statistic. As a result, correct number of chemical reaction can be obtained from significant nonzero eigenvalues.Finally, This approach provides a solid basis to obtain insight into subtle spectral variations caused by intermolecular interaction. It can be used as an effective tool for our future work.