Spectroscopy, Structure and Bonding, Kinetics and Dynamics

Arunan's comments on the recent paper on covalency in hydrogen bond published by Chemistry World

PCCP blogs about Arunan's Editotial in Current Science

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