A Novel Approach Based on Two-Dimensional Correlation Spectroscopy to Determine the Stoichiometric Ratio of Two Substances Involved in Intermolecular Interactions

Abstract

A novel technique called AOSD@Job’s, combining asynchronous orthogonal sample design scheme (AOSD) with Job’s method, is proposed to estimate the stoichiometric ratio of two substances that form a supramolecular aggregate under intermolecular interactions. First, a mathematical analysis was performed along with the procedure of the AOSD@Job’s method. Then, the validity of the AOSD@Job’s method was manifested by computer simulation on two model systems. Finally, the AOSD@Job’s method was applied on two real chemical systems. The stoichiometric ratio between the coordination complex of Ni2+ and ethylenediaminetetraacetic acid disodium salt (EDTA) was estimated to be 1.0. Benzyl alcohol (BA) and β-cyclodextrin (β-CD) were determined to form a 1 : 1 host–guest complex. These values were consistent with the values reported in the literature. Compared with the traditional Job’s method, the AOSD@Job’s method has an evident advantage since it is still valid even if all the peaks of the supramolecular aggregate severely overlap with the peaks of the substances that form the aggregate.

A new approach to recognizing the correct pattern of cross-peaks from a noisy 2D asynchronous spectrum by detecting intrinsic symmetry via the Kolmogorov–Smirnov test

“…Estimation of the stoichiometric ratio of the supramolecular complex is very important in elucidating the structure and function of the supramolecular complex. In our previous work, a technique called the AOSD@Job's method 53 is developed to estimate the stoichiometric ratio.…”

Robust Approach to Estimating the Stoichiometric Ratio of Supramolecular Complexes Using the Volume of Cross-Peaks in 2D Asynchronous Spectra and the Jonckheere–Terpstra Test

“…We noticed that asynchronous orthogonal sample design (AOSD), an approach in the toolbox of OSD and relevant techniques, may provide a chance to access the problem. Thus, we combined AOSD with Job’s method (denoted as AOSD@Job’s method hereafter) to address the problem in our previous work …”

“…Thus, we combined AOSD with Job's method (denoted as AOSD@Job's method hereafter) to address the problem in our previous work. 35 In AOSD@Job's method, 35 n 2D asynchronous spectra are generated via the AOSD approach. We have mathematically proven that the intensities of cross-peaks are proportional to the equilibrium concentration of P a Q b in the corresponding solutions containing P and Q (Section 1 of part 1 of Supporting Information).…”

Intermolecular Interactions in the Polymer Blends Under High-Pressure CO2 Studied Using Two-Dimensional Correlation Analysis and Two-Dimensional Disrelation Mapping

“…7,9,12 It can also be used to study intermolecular interactions. [13][14][15] As an extension of conventional 2D correlation analysis, disrelation mapping, proposed by Shinzawa et al in 2017, is a technique to highlight the specific areas where disrelated variation occurs between Wavenumber 1 (n 1 ) and Wavenumber 2 (n 2 ). To be more specific, a convolution filter, which can be viewed as a spatial filter based on the 2D correlation function, was designed to identify the places where an out-of-phase change in the absorbance of two different spectral bands occurs.…”