S Sankararaman

Indian Institute of Technology Madras, Chennai

Sethuraman Sankararaman completed B.Sc at the Hindu College, Tirunelveli, in 1979 and M.Sc from IIT Madras in 1981. He completed his doctoral thesis in 1985 with Al-fred Fischer at the University of Victoria, Canada. After five years of postdoctoral research with Jay K. Kochi at the University of Houston, USA, he returned to India in 1991 and took up a faculty position at IIT Madras. He is currently an Institute Chair professor at IIT Madras. He has received fellowships from the DAAD, INSA-DFG and the Alexander von Humboldt Foundation. He is interested in acetylene and olefin chemistry, the study of π− π interactions and hydrogen bonding interactions and organic molecules in energy storage applications. He is also interested in PdNHeterocyclic carbene complexes and carbonylation. He authored a book on Pericyclic Reactions a Textbook, published by WileyVCH in 2005. He has 26 years of teaching experience at IIT Madras. He was elected Fellow of Indian Academy of Sciences in 2017.

S Sankararaman

Session 2B: Inaugural Lectures by Fellows

Chairperson: Veena K Parnaik, Centre for Cellular & Molecular Biology, Hyderabad

Restricting rotation of triple bond through π-stacking interactions in molecular hinges

Restricting the rotation of carbon-carbon triple bonds is much more difficult than that of C-C single bonds, due to low activation barriers and lack of any steric hindrance due to substituents. Restricted rotation of C-C triple bonds is important from the point of view of molecular chirality of πextended biphenyls. Literature examples of restricted rotation of acetylenic bond in diphenylethyne derivatives deal with steric (repulsive) interactions among the bulky silyl and aryl substituents placed in the ortho positions of the phenyl groups. The question of interest is whether or not it is possible to restrict acetylenic bond rotation through weak non-covalent attractive forces such as π− π interactions between large aromatic units. To address this issue the speaker and his group have designed and synthesised a series of molecular hinges with pyrene chromophore as wings. The first ever example of isolation and X-ray crystallographic structural characterisation of two conformers arising from rotation along a diacetylenic bond was, in fact, reported from their laboratory.

© 2017 Indian Academy of Sciences, Bengaluru.