Molecular Dynamics of Steroidal Rotors Probed by Theoretical, Spectroscopic and Dielectric Methods

• Published in: Chemistry : a European journal Vol. 30; no. 20; pp. e202303933 - n/a
• Main Authors: Olszewska, Karolina, Mizera, Adam, Ławniczak, Paweł, Kamińska, Anna, Santillan, Rosa, Morales‐Chamorro, Maricela, Ochoa, Ma. Eugenia, Farfán, Norberto, Łapiński, Andrzej, Górecki, Marcin, Jastrzebska, Izabella, Runka, Tomasz
• Format: Journal Article
• Language: English
• Published: WEINHEIM Wiley 05.04.2024; Wiley Subscription Services, Inc
• Subjects: Chemistry; Chemistry, Multidisciplinary; Circular dichroism; Crystals; Density functional theory; DFT calculations; Dichroism; dielectric analysis; Electrons; Fluorine; Frequency; Infrared spectroscopy; Librational motion; Molecular dynamics; molecular rotors; Physical Sciences; Raman spectra; Raman spectroscopy; Rotors; Science & Technology; Spectra; Spectroscopy; Spectrum analysis; vibrational spectroscopy; CIRCULAR-DICHROISM; GYROSCOPES; COMPASSES; molecular rotors; AMPHIDYNAMIC CRYSTALS; vibrational spectroscopy; circular dichroism; DENSITY-FUNCTIONAL THEORY; SPECTRA; dielectric analysis; DFT calculations
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.202303933

Our study focuses on molecular rotors with fast‐moving rotators and their potential applications in the development of new amphidynamic crystals. Steroidal molecular rotors with a dipolar fluorine‐substituted phenyl group as the rotator were synthesized and characterized. Three different rotors were investigated with varying numbers of fluorine atoms. A comprehensive analysis was performed using vibrational spectroscopy (Raman, FT‐IR), electronic circular dichroism (ECD), and dielectric response to understand the behavior of the investigated model rotors. The results were supported by theoretical calculations using Density Functional Theory (DFT) methods. The angle‐dependent polarized Raman spectra confirmed the crystallinity of the samples. Nearly frequency and temperature‐independent permittivity suggest low‐frequency librational motion of stators. An in‐depth analysis of ECD spectra revealed high conformational flexibility in solution, resulting in low ECD effects, while in the solid‐state with restricted rotation, significant ECD effects were observed. These findings shed light on the conformational behavior and potential applications of the studied steroidal molecular rotors. Three different steroidal molecular rotors with a dipolar fluorine‐substituted phenyl group rotator were synthesized. Raman and FT‐IR measurements were used to analyse the effect of fluorine substitution on molecular dynamics of the phenyl ring. The electric properties were investigated with the impedance spectroscopy. ECD spectroscopy was used to approximate the solid‐state structure of one of the rotors.