Advances, challenges and perspectives of quantum chemical approaches in molecular spectroscopy of the condensed phase

Abstract

The purpose of this review is to demonstrate advances, challenges and perspectives of quantum chemical approaches in molecular spectroscopy of the condensed phase.

NIR spectroscopy – What a wonderful world!

“…Figure 2 shows the experimental and calculated NIR spectra in the 7300-3700 cm À1 region of low concentration (5 Â 10 À3 M CCl 4 ) methanol with band assignments. 10,15 Band positions and intensities of overtones and combinations are reproduced well by anharmonic calculations. They moved to University of Innsbruck, and together with Huck, they extended these calculation studies to more complicated molecules such as nucleic acids, rosemary acid, caffeine, and polymers.…”

“…Futami, Bec, and Grabska were pioneers in our group in the applications of quantum chemical calculations to NIR spectroscopy. 1,5,6,10,15 Futami et al compared hydrogen bonding effects and solvent effects on wavenumbers and intensities of the fundamental and first overtone of the N-H stretching mode of pyrrole using NIR/IR spectroscopy and onedimensional vibrational Schr€ odinger equation approach. 1,5,6,10 Upon the formation of a hydrogen bonding, the intensity of a band due to the fundamental becomes strong while that of a band derived from the corresponding first overtone becomes weak.…”

“…Bec and Grabska have opened a new era of applications of quantum chemical calculations to NIR spectroscopy. 10,15 Quantum chemical calculations of entire NIR spectra were almost impossible because of the markedly increased complexity of theoretical description of the anharmonic effects. Bec and Grabska utilized anharmonic calculations nicely for reproducing NIR spectra of a variety of molecules including medium size molecules such as long chain fatty acids.…”

Anharmonicity and Spectra–Structure Correlations in MIR and NIR Spectra of Crystalline Menadione (Vitamin K3)

“…In contrast, the studies of the spectra-structure relationships in near-infrared (NIR) range are rare. First of all, it results from higher complexity of NIR spectra as compared with IR or Raman ones [29][30][31]. As a result, no successful investigations of the overtones and combination bands of vitamins have been reported so far.…”

“…Recent progress in the hardware and new theoretical methods allows the calculations of NIR spectra and improve their interpretability [29,30,33]. This gives an opportunity to explore NIR spectra of vitamins and their relationships with the IR ones.…”