Prof. E. Arunan gave an online lecture organized by the International Conference on Noncovalent Interactions on 5th July 2021, a part of a nine-lecture series by various researchers across three continents. Prof. Arunan's lecture was recorded and can be watched again here.

Video recordings of talks at the workshop on 100 Years of Hydrogen Bonding (9-10 January, 2020).

Chemical bonding in period 2 homonuclear diatomics

Note: UG/PG students from outside IISc - Internship/summer projects not available in our laboratory for the year 2024.

Click here to visit our group home page.

Our research focuses on molecular and van der Waals spectroscopy, chemical kinetics and dynamics and inter-intramolecular bonding. Our laboratory uses home-build facilities to do experiments and also carries out computational and modeling work to enhance our understanding.

We have built the first Pulsed Nozzle Fourier Transform Microwave Spectrometer in India. This is being used to study the rotational spectra of weakly bound complexes formed in a supersonic expansion. Based on the bulk properties, Pauling had concluded that water being a liquid can form hydrogen bonds and hydrogen sulphide remains a gas as it has weak van der Waals interactions. After a detailed investigations of a series of complexes formed by H₂O and H₂S, we showed that both can form hydrogen bonds. Following our efforts, IUPAC changed the definition of hydrogen bond in 2011. Microwave spectroscopic and theoretical investigations on argon-proparhyl alcohol led us to the 'carbon bonding', analogous to the hydrogen bonding. Our work on 'carbon bonding' has in a way completed the quest of chemists to find intermolecular bonding by atoms beyond hydrogen.

Shock tube studies are being carried out, in collaboration with Aerospace Engineering Department, on the kinetics of unimolecular and bimolecular chemical reactions. A single pulse shock tube facility has been used to study thermal decomposition of several molecules. This facility has also been used to measure the ignition delay of fuels that are of interest to Space and Defense organizations. For more information, please visit the website of the Laboratory for Hypersonic and Shockwave Research (LHSR).

Representative Publications

• Effects of Multiple OH/SH Substitution on the H-Bonding/Stability versus Aromaticity of Benzene Rings: From Computational Insights
  S. K. Pandey and E. Arunan
  ChemistrySelect 6, 5120-5139 (2021)
   
  DOI:  doi.org/10.1002/slct.202100689
• Coriolis Interactions in benzene-water and related molecular complexes
  P. Halder, M. S. Krishnan, and E. Arunan
  J. Mol. Spectrosc. 370, 111277 (2020)
   
  DOI:  10.1016/j.jms.2020.111277
• A Detailed Classification of three-centre-two-electron Bonds
  S. P. Gnanasekar and E. Arunan
  Aust J. Chem. 73, 766-774 (2020)
   
  DOI:  10.1071/CH19557
• Chemical bonding in Period 2 homonuclear diatomic molecules: a comprehensive relook
  A. Das and E. Arunan
  J Chem Sci 131, 120 (2019)
   
  DOI:  10.1007/s12039-019-1707-5
• H₂S Dimer is Hydrogen Bonded: Direct Confirmation from Microwave Spectroscopy
  A. Das, P. K. Mandal, F. J. Lovas, C. Medcraft, N. R. Walker and E. Arunan
  Angew. Chem. Intl. Ed. 57, 15199-15203 (2018)
   
  DOI: 10.1002/anie.201808162
• Theoretical investigation of reaction kinetics and thermodynamics of the keto-enol tautomerism of 1, 3, 5-triazin-2, 4(1H, 3H)-dione and its substituted systems utilizing density functional theory and transition state theory methods
  P. M. Singh, H. K. Chakravarty, S. K. Jain, A. Pathak, M. K. Singh and E. Arunan
  Comput. Theor. Chem. 1141, 15-40 (2018)
   
  DOI: 10.1016/j.comptc.2018.08.013
• Interstellar Hydrogen Bonding
  E. E. Etim, P. Gorai, A. Das, S. K. Chakrabarti, and E. Arunan
  Adv. Space Res.61, 2870-2880 (2018)
   
  DOI: 10.1016/j.asr.2018.03.003