Things on which I'm Currently working

Study Plan for Mr Vikash Meghwal

Title: Role of Hydrophobicity on Synergistic Solvation

Synergistic solvation is a novel observation by Dr. Sen group at IIT Kanpur in 2012. Over the years, one of the projects of our group is to comprehend the physical understanding and mechanism of this observation.

The non-ideality in the binary solvent mixture is manifested through anomaly in various physical properties like viscosity, dielectric constant, polarity, freezing point, boiling point and so forth. Sometimes, such anomalies become useful in chemistry and biology. From a physical chemist's perspective, understanding such a novel feature is fascinating to us. The source or non-ideality in a binary solvent mixture can be broadly categorized in two cases: preferential and synergistic solvation. The synergistic effect in various primary alcohols/chlorinated methane has been thoroughly studied by our group and is attributed to unique hydrogen bonding. Using 1H-NMR spectroscopy, we found that methanol and chloroform form a 1:2 H- bonded complex between them, which possess a more polar environment than the individual solvents (J. Phys. Chem. B 2012, 116, 1345; Phys. Chem. Liq. 2018, 56, 496). The solvation time was found to be maximum in XMeOH= 0.45 in the same system (J. Phys, Chem. B2015, 119, 3135). Recently, we observed the characteristic spectral band due to chloroform-methanol hydrogen-bonds using optical Kerr effect spectroscopy (J. Mol. Liq. 2021. In Press https://doi.org/10.1016/j.molliq.2021.117013). Similar type of synergism was observed for ethanol/chloroform and t-butanol/chloroform solvent mixtures (J. Mol. Liq. 2016, 223, 274; J. Sol. Chem. 2017, 46, 461). Interestingly, carbon tetrachloride, which does not have any donor hydrogen, does not show synergism with primary alcohols. Finally, the  t-butanol/dichloromethane binary solvent mixture was shown to affect the yield of a chemical reaction's product due to synergistic solvation.

In the project, the proposed study is to understand the role of hydrophobicity on the synergistic solvation behavior. For this the proposed systems are:-

Ethylene Glycol/2-methoxy ethanol/dimethoxy ethane + water binary solvent mixture

Formamide/N-methyl formamide/dimethyl formamide + water binary solvent mixture

The following experiments are proposed to be done

1. NMR 

2. Raman

3. Polarity using fluorescence and absorption 

4. Refractive index

5. Sound velocity 

6. Temperature dependent