3 years ago

Hyperconjugative effects in π-hydrogen bonding: Theory and experiment

Hyperconjugative effects in π-hydrogen bonding: Theory and experiment
Diana Cheshmedzhieva, Valia Nikolova, Boriana Hadjieva, Boris Galabov, Henry F. Schaefer
Density functional theory computations with the B3LYP/6-311++G(2df,2p) method and IR spectroscopy are employed in investigating the properties of twenty π-hydrogen bonded complexes between substituted phenols and hexamethylbenzene. All complexes possess T-shaped structures. The methyl hyperconjugative effects on interactions energies and OH stretching frequencies are estimated via comparisons with previously reported theoretical and experimental results for analogous phenol complexes with benzene. The theoretical computations provide excellent quantitative predictions of the OH stretching frequency shifts (ΔνOH) resulting from the hydrogen bonding. The ΔνOH shifts in the hexamethylbenzene complexes are approximately twice as large as the corresponding shifts for the benzene complexes. Hirshfeld charges, electrostatic potential at nuclei values, and molecular electrostatic potential maps are employed in gaining insights into the mechanisms of methyl hyperconjugative effects on complex formation. © 2017 Wiley Periodicals, Inc. Infrared spectroscopy and density functional theory computations at B3LYP/6-311++G(2df,2p) are employed in characterizing the methyl hyperconjugative effects on the π-hydrogen bonding between hexamethylbenzene and substituted phenols. Comparisons with analogous theoretical and experimental data for the complexes of phenols with benzene provide a quantitative measure of the hyperconjugation influence on interaction energies and OH frequency shifts. Molecular electrostatic potential characteristics explain well the spectroscopic features and the variations of hydrogen bonding energies.

Publisher URL: http://onlinelibrary.wiley.com/resolve/doi

DOI: 10.1002/jcc.25088

You might also like
Discover & Discuss Important Research

Keeping up-to-date with research can feel impossible, with papers being published faster than you'll ever be able to read them. That's where Researcher comes in: we're simplifying discovery and making important discussions happen. With over 19,000 sources, including peer-reviewed journals, preprints, blogs, universities, podcasts and Live events across 10 research areas, you'll never miss what's important to you. It's like social media, but better. Oh, and we should mention - it's free.

  • Download from Google Play
  • Download from App Store
  • Download from AppInChina

Researcher displays publicly available abstracts and doesn’t host any full article content. If the content is open access, we will direct clicks from the abstracts to the publisher website and display the PDF copy on our platform. Clicks to view the full text will be directed to the publisher website, where only users with subscriptions or access through their institution are able to view the full article.