Quantum chemical calculation of NIR spectra of practical materials

Abstract

In the third issue of the series on modern quantum chemical methods in the support role of NIR spectroscopy we continue to introduce the researchers from the field of experimental spectroscopy to practical aspects and applications of modern anharmonic theoretical approaches. The first two issues focused on explaining the necessary theoretical and practical background, allowing readers to get more familiar with the topic. An overview of recent literature reports highlighted the advantages stemming from using quantum chemical calculation in the support role to NIR spectroscopy. These deliberations were based on several cases of small- to medium-sized molecules. This part overviews the topic of applications of quantum theoretical methods to complex molecules with practical significance, which typically prove to be challenging objects for theoretical studies. An exemplary application of presented methodology to the case of Rosmarini folium biological samples is also examined here. The rosemary specific active compound, rosmarinic acid, is a relatively complex polyphenol with growing phytopharmaceutical importance, and therefore provides an excellent object of applied studies. The possibilities of combining the information stemming from quantum chemical calculation with the methods of advanced spectral data analysis, which are commonly used in experimental NIR spectroscopy (chemometrics, two-dimensional (2D) correlation spectra) are also overviewed. Again, these deliberations are based directly on the most recent reports published in the field.