Variable temperature FTIR spectra of polycrystalline purine nucleobases and estimating strengths of individual hydrogen bonds
| Autor: | Igor Reva, Mark Rozenberg, Rui Fausto |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Imine
Stacking 02 engineering and technology 010402 general chemistry 01 natural sciences Analytical Chemistry Nucleobase Crystal chemistry.chemical_compound Spectroscopy Fourier Transform Infrared Instrumentation Spectroscopy Hypoxanthine Quantitative Biology::Biomolecules Hydrogen bond Atoms in molecules Temperature Hydrogen Bonding 021001 nanoscience & nanotechnology Atomic and Molecular Physics and Optics 0104 chemical sciences chemistry Quantum Theory Thermodynamics Physical chemistry Crystallite 0210 nano-technology |
| Zdroj: | Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy. 251:119323 |
| ISSN: | 1386-1425 |
| DOI: | 10.1016/j.saa.2020.119323 |
| Popis: | In the first part of this work, we report the FTIR spectra of pure NH and isotopically substituted ND (10–15% D and 80–90% D) polycrystalline hypoxanthine, xanthine, adenine and guanine recorded in the 400–4000 cm−1 range, as a function of temperature (10–300 K). We provide assignments of the stretching and out-of-plane bending amine (NH2) and imine (NH) bands to the distinct H-bonds present in the crystal, based on the temperature sensitivity and isotopic exchange behavior. Empirical correlations between spectral and thermodynamic or structural parameters enabled us to estimate the energies and lengths of H-bonds in the studied nucleobase crystals and to correlate them with literature data. The empirical H-bonding energies are compared with H-bonding and stacking energies computed for hypoxanthine. In the second part, strategies for using the empirical correlations together with information extracted from quantum mechanical data (in particular from the Bader’s quantum theory of atoms in molecules, QTAIM) for the evaluation of hydrogen bonding properties are discussed, and their advantages and drawbacks pointed out. The justification for a cooperative use of quantum-mechanical calculations with empirical spectra-energy correlations is discussed. |
| Databáze: | OpenAIRE |
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