Anomalous Dynamics in tert-Butyl Alcohol-Water and Trimethylamine N-Oxide-Water Binary Mixtures: A Femtosecond Transient Absorption Study

Debasis Banik; Sayantan Bhattacharya; Prasanta Kumar Datta; Nilmoni Sarkar

doi:10.1021/acsomega.7b01595

Anomalous Dynamics in tert-Butyl Alcohol-Water and Trimethylamine N-Oxide-Water Binary Mixtures: A Femtosecond Transient Absorption Study

ACS Omega. 2018 Jan 11;3(1):383-392. doi: 10.1021/acsomega.7b01595. eCollection 2018 Jan 31.

Authors

Debasis Banik¹, Sayantan Bhattacharya¹, Prasanta Kumar Datta¹, Nilmoni Sarkar¹

Affiliation

¹ Department of Chemistry and Department of Physics, Indian Institute of Technology, Kharagpur 721302, West Bengal, India.

Abstract

In this article, we have investigated the unusual dynamics of tert-butyl alcohol (TBA)-water and trimethylamine N-oxide (TMAO)-water binary mixtures using solvation dynamics as a tool. For this purpose, femtosecond transient absorption spectroscopy has been employed. Although these two molecules are isosteres to each other, a significant difference in water dynamics has been observed. The solvation times in TBA-water binary mixtures are found to be between 1.5 and 15.5 ps. On the contrary, we have observed very fast dynamics in TMAO-water binary mixtures (between 210 and 600 fs). Interestingly, unusual retardation in dynamics is observed at 0.10 mole fraction of TBA and TMAO in both the binary mixtures.