The formation and strengthening of hydrogen bonds (H-bonds) manifests itself in striking geometric and spectral characteristics of complexes. So much so that these manifestations constitute the majority of H-bond formation criteria [1], while spectroscopic parameters become essential probes for H-bond diagnostics [2]. For example, bridging proton deshielding in NMR spectra and red-shift of proton donor stretching frequency in IR spectra are among widely known and reliable H-bond predictors. Сonstruction of new predictive correlations is in high demand, especially for the characterisation of soft matter, where the direct information on interatomic distances and complexation energies is hard to obtain. There are two main advantages of using a combination of NMR and IR for the study of H-bonded complexes. Firstly, all NMR and IR spectroscopic parameters could be roughly divided into two major groups: those that change monotonously upon gradual proton displacement (markers for the proton transfer degree) and those that pass an extremum for short strong H-bonds (markers for the hydrogen bond length or complexation energy). It is clearly advantageous to combine parameters from both groups, which in many cases becomes easier if both types of spectroscopy are considered. Secondly, experimental measurement of NMR and IR spectra often requires different techniques of sample preparation and different measurement conditions, which leads to only partially consistent spectral data. One of the most dramatic effects is due to the difference in characteristic times: NMR spectral data are averaged over much longer periods of time. This could be a curse or a blessing in disguise: NMR and IR might provide complementary “views” on the same system. In this presentation we overview the results obtained over the last couple of years, concerning the construction of NMR [3–5] and IR [6–9] hydrogen bond correlations for various intermolecular hydrogen-bonded complexes. We also briefly touch the subject of halogen bonds [10, 11] and NMR/UV-vis combination [12]. This work presents some of the results obtained under support of the Russian Science Foundation (grant Nos. 18-13-00050 (complexes with isolated H-bonds) and 23-13-00095 (complexes with chains of cooperative H-bonds)). References:
1. E. Arunan, G.R. Desiraju, R.A. Klein, J. Sadlej, S. Scheiner, I. Alkorta, D.C. Clary, R.H. Crabtree, J.J. Dannenberg, P. Hobza, H.G. Kjaergaard, A.C. Legon, B. Mennucci, D.J. Nesbitt, Pure Appl. Chem. 83, 1637–1641 (2011).
2. P.M. Tolstoy, E.Yu. Tupikina, “IR and NMR spectral diagnostics of hydrogen bond energy and geometry,” in Spectroscopy and Computation of Hydrogen-Bonded Systems, Ed. by Marek J. Wojcik, Y. Ozaki (John Wiley and Sons, 2023), pp. 345–407.
3. I.S. Giba, V.V. Mulloyarova, G.S. Denisov, P.M. Tolstoy, Magn. Reson. Chem. 59, 465-477 (2021).
4. V.V. Mulloyarova, D.O. Ustimchuk, A. Filarowski, P.M. Tolstoy, Molecules 25, 1907 (2020).
5. V.V. Mulloyarova, I.S. Giba, G.S. Denisov, P.M. Tolstoy, J. Phys. Chem. A 123, 6761–6771 (2019).
6. E.Yu. Tupikina, V.O. Korostelev, D.V. Krutin, P.M. Tolstoy, Phys. Chem. Chem. Phys. 25, 8664–8675 (2023).
7. E.Yu. Tupikina, P.M. Tolstoy, A.A. Titova, M.A. Kostin, G.S. Denisov, J. Comput. Chem. 42, 564–571 (2021).
8. E.Yu. Tupikina, K.G. Tokhadze, V.V. Karpov, G.S. Denisov, P.M. Tolstoy, Spectrochim. Acta A 241, 118677 (2020).