PMC

The spectrum of absorption coefficient of liquid water.

The properties of near-infrared spectroscopy create unique synergy with quantum mechanical spectra simulations.

Experimental (0.2 M; CCl₄) and simulated (VPT2//B3LYP/SNST+CPCM) NIR spectra of (A) cyclohexanol and (B) phenol. Reprinted with permission from Elsevier (Beć et al., ).

Simulated NIR spectra of CXXXOX (X = H, D) molecules. Reprinted with permission from Grabska et al. (). Copyright 2017 American Chemical Society.

Vibrational potential and vibrational states [B3LYP/6-311G(d,p)] of the OH stretching mode of the main (equatorial-gauche) conformer of cyclohexanol. Reprinted with permission from Elsevier (Beć et al., ).

The experimental (powder) and theoretical NIR spectrum of rosmarinic acid obtained in anharmonic GVPT2//DFT-B3LYP/N07D simulation (Kirchler et al., ). Reproduced by permission of The Royal Society of Chemistry.

Band assignments proposed for NIR spectra of MCFAs in medium to high concentration (CCl₄); (A) hexanoic acid, (B) sorbic acid. Reprinted with permission from Elsevier (Grabska et al., ).

The experimental FT-NIR spectrum of aqueous malic acid in comparison with the PT2-VSCF derived line spectrum. Reprinted from Schmutzler et al. (). Reprinted with permission from Nova Science Publishers, Inc.].

Convolution of NIR bands on the example of spectra simulation for vinylacetic acid. All bands are presented in common intensity, note an extensive band overlay. Reprinted with permission from Grabska et al. (). Copyright 2017 American Chemical Society.

Generalized contributions into NIR spectra of the selected types of modes involved in the binary combinations as uncovered by quantum mechanical spectra simulation of linoleic and palmitic acid. (Reprinted with permission from Grabska et al. (). Copyright (2018) American Chemical Society).

NIR spectra of diluted methanol; experimental (5 10⁻³ M CCl₄) and simulated by the use of anharmonic calculations (GVPT2 scheme on DFT-B2PLYP/SNST level of electronic theory and CPCM solvation model of CCl₄) (Beć et al., ). Reproduced by permission of the PCCP Owner Societies.

Band assignments in the experimental and calculated NIR spectra of low concentration (5 10⁻³ M CCl₄) ethanol. The calculated NIR spectrum is based on the CPCM-B2PLYP-D/SNST level of theory. Details of the 5,200–4,600 cm⁻¹ region (Beć et al., ). Reproduced by permission of the PCCP Owner Societies.

The analysis of mode contribution into NIR spectrum of thymol (solution; 100 mg mL⁻⁻¹ CCl₄) based on the simulated data (DVPT2//DFT-B3LYP/SNST+CPCM). (A) Experimental and simulated outlines. (B) Contributions of selected modes as described on the figure (Reprinted with permission from Beć et al., ).

Experimental (solution; CCl₄) and modeled spectrum of acetic acid. Band fitting results for the two combination bands involving OH stretching modes of acetic acid cyclic dimer. Reprinted with permission from Beć et al. (). Copyright 2016 American Chemical Society.

Experimental and simulated (harmonic: B2PLYP/def2-TZVP; VPT2: B3LYP/SNST; CPCM) NIR spectra of butyl alcohols; (A) 1-butanol; (B) 2-butanol; (C) iso-butanol; (D) tert-butyl alcohol. The contributions of the spectral lineshapes corresponding to conformational isomers presented as well (colored lines). Reprinted with permission from Grabska et al. (). Copyright 2017 American Chemical Society.

A set of the experimental NIR spectra of thymol; solid state and melted (neat liquid, 333 K) as well as diluted in CCl₄ (100 and 10 mg mL⁻¹ CCl₄). Highlighted are the wavenumber regions qualitatively independent of sample phase and concentration; (A) 6,000–5,600 cm⁻¹; (B) 4,490–4,000 cm⁻¹ (Reprinted with permission from Beć et al., ).