Solvent Effects and Aggregation Phenomena Studied by Vibrational Optical Activity and Molecular Dynamics: The Case of Pantolactone
Authors: Ghidinelli S., Abbate S., Koshoubu J., Wada T., Longhi G.
Autors Affiliation: Univ Brescia, Dipartimento Med Mol & Traslazionale, I-25123 Brescia, Italy; CNR, Res Unit Brescia, Ist Nazl Ott INO, I-25123 Brescia, Italy; JASCO Corp, Hachioji, Tokyo 1928537, Japan; Tohoku Univ, Inst Multidisciplinary Res Adv Mat, Sendai, Miyagi 9808577, Japan
Abstract: Raman and Raman optical activity (ROA), IR, and vibrational circular dichroism (VCD) spectra of (R)- and (S)-pantolactone have been recorded in three solvents. ROA has been employed on water and DMSO solutions, VCD on DMSO and CCl(4 )solutions. In the last solvent, monomer-dimer equilibrium is present. Due to the low conformational flexibility of the isolated molecule and to the possibility of aggregation, this compound has been used here to test different protocols for computation of the spectroscopic responses taking into account solvent effects. Molecular dynamics (MD) simulations have been carried out together with statistical clustering methods based on collective variables to extract the structures needed to calculate the spectra. Quantum mechanical DFT calculations based on PCM are compared with approaches based on different representations of the solvent shell (MM or QM level). Appropriate treatment of the solvent permits obtaining of good band-shapes, with the added advantage that the MD analysis allows one to take into account flexibility of dimeric structures justifying the broadness of observed bands and the absence of intense VCD couplets in the carbonyl and OH stretching regions.
Journal/Review: JOURNAL OF PHYSICAL CHEMISTRY B
Volume: 124 (22) Pages from: 4512 to: 4526
KeyWords: CIRCULAR-DICHROISM; CONFORMATIONAL-ANALYSIS; RAMAN; SPECTRA; RING; SIMULATION; CHIRALITY; SETDOI: 10.1021/acs.jpcb.0c01483Citations: 2data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2021-02-28References taken from IsiWeb of Knowledge: (subscribers only)Connecting to view paper tab on IsiWeb: Click hereConnecting to view citations from IsiWeb: Click here