Absorption and Isomerization of Azobenzene Guest Molecules in Polymeric Nanoporous Crystalline Phases

• Main Authors: Nicola Coscia, Antonietta Cozzolino, Manohar Golla, Paola Rizzo
• Format: Article
• Language: English
• Published: MDPI AG 2021-09-01
• Series: Chemistry
• Subjects: poly(2,6-dimethyl-1,4-phenylene)oxide; co-crystalline phase; confined isomerization; FTIR spectra; UV-Vis spectra
• Online Access: https://www.mdpi.com/2624-8549/3/3/78

PPO co-crystalline (CC) films including azobenzene guest molecules have been prepared and characterized by WAXD, FTIR and UV-Visible measurements. Isomerization reactions of azobenzene (photo-induced trans to cis and spontaneous cis to trans) included in α and β nanoporous-crystalline (NC) phases leading to CC phases, or simply absorbed in amorphous phase have been studied on thick and thin films. Spectroscopic analysis shows that photo-isomerization of azobenzene occurs without expulsion of azobenzene guest molecules from crystalline phases. Sorption studies of α and β NC films immersed into photo-isomerized azobenzene solution reveal a higher selectivity of the β NC phase toward cis azobenzene isomer than the α NC phase, inducing us to propose the β NC phase as particularly suitable for absorbing spherically bulky guest molecules.