01866nas a2200193   4500008004100000022001400041245008200055210006900137260000800206300001400214490000800228520123100236100002701467700002701494700001801521700001801539700001601557856009901573       2022                        eng d  a1520-610600aOn-off infrared absorption of the S=O vibrational probe of dimethyl sulfoxide0 aOnoff infrared absorption of the SO vibrational probe of dimethy  cJUN  a4501-45080 v1263 a<p>
	Dimethyl sulfoxide (DMSO), a polar solvent molecule, is used in a wide range of therapeutic and such as dimerization and hydrogen bonding with water, are crucial to understanding the role of DMSO in applications. Herein, we study DMSO in various solvation environments to decipher the environment-dependent dimerization and hydrogen-bonding propensity. We use a combination of infrared spectroscopy, quantum mechanical calculations, and molecular dynamics simulations to reach our conclusions. Although DMSO can exist in a dynamic equilibrium between monomers and dimers, our results show that the relative intensity of the S=O stretch and the CH3 rocking modes is a spectroscopic indicator of the extent of DMSO dimerization in solution. The dimerization (self-association) is seen to be maximum in neat DMSO. When dissolved in different solvents, the dimerization propensity decreases with increasing solvent polarity. In the presence of a protic solvent, such as water, DMSO forms a hydrogen bond with the solvent molecules, thereby reducing the extent of dimerization. Further, we estimate the hydrogen-bond occupancy of DMSO. Our results show that DMSO predominantly exists as doubly hydrogen-bonded in water.</p>
1 aChakrabarty, Suranjana1 aDeshmukh, Samadhan, H.1 aBarman, Anjan1 aBagchi, Sayan1 aGhosh, Anup  uhttps://library.ncl.res.in/content/infrared-absorption-so-vibrational-probe-dimethyl-sulfoxide