Excited-State Intramolecular Proton Transfer: Photoswitching in Salicylidene Methylamine Derivatives

• Published in: Chemphyschem Vol. 15; no. 8; pp. 1643 - 1652
• Main Authors: Jankowska, Joanna, Rode, Michał F., Sadlej, Joanna, Sobolewski, Andrzej L.
• Format: Journal Article
• Language: English
• Published: Weinheim WILEY-VCH Verlag 06.06.2014; WILEY‐VCH Verlag; Wiley; Wiley Subscription Services, Inc
• Subjects: ab initio calculations; Atomic and molecular physics; Chemistry; conical intersection; Exact sciences and technology; General and physical chemistry; molecular photoswitch; Physics; proton transfer; schiff bases; Schiff bases; molecular photoswitch; ab initio calculations; Ab initio method; Proton transfer; Calculus; Photophysics; conical intersection; proton transfer; schiff bases
• ISSN: 1439-4235; 1439-7641
• DOI: 10.1002/cphc.201301205

The effect of chemical substitutions on the photophysical properties of the salicylidene methylamine molecule (SMA) (J. Jankowska, M. F. Rode, J. Sadlej, A. L. Sobolewski, ChemPhysChem, 2012, 13, 4287–4294) is studied with the aid of ab initio electronic structure methods. It is shown that combining π‐electron‐donating and π‐electron‐withdrawing substituents results in an electron‐density push‐and‐pull effect on the energetic landscape of the ground and the lowest excited ππ* and nπ* singlet states of the system. The presented search for the most appropriate SMA derivatives with respect to their photoswitching functionality offers an efficient prescreening tool for finding chemical structures before real synthetic realization. Flick that switch: A theoretical attempt to control the photophysical properties of salicylidene methylamine‐based molecular systems through a chemical substitution effect is reported (see figure; CI=conical intersection, PT=proton transfer). An electron‐density push‐and‐pull effect is shown to be a promising tool for efficient photoswitching control.