The role of microenvironments on computed vibrationally‐resolved emission spectra: The case of oxazines

• Published in: Journal of computational chemistry 2024-10, Vol.45 (26), p.2232-2241
• Main Authors: Nguyen Thi Minh, Nghia, König, Carolin
• Format: Article
• Language: English
• Subjects: Dyes; Electronic structure; Emission spectra; Environment models; Fluorescence; microenvironment; Molecular structure; oxazine; vibrational profile; vibronic spectra; Water chemistry
• ISSN: 0192-8651; 1096-987X; 1096-987X
• DOI: 10.1002/jcc.27385

Oxazine dyes act as reporters of their near environment by the response of their fluorescence spectra. At the same time, their fluorescence spectra exhibit a pronounced vibrational progression. In this work, we computationally investigate the impact of near‐environment models consisting of aggregated water as well as betaine molecules on the vibrational profile of fluorescence spectra of different oxazine derivatives. For aggregated betaine and a water molecule located above the plane of the dyes, we observe a distinct modification of the vibrational profile, which is more pronounced than the effect of a continuum description of a solvent environment. Our analysis shows that this effect cannot be explained by a pure change in the electronic structure, but that also vibrational degrees of freedom of the environment can be decisive for the vibrational profile and should, hence, not generally be neglected.