From Jabłoński To Femtoseconds. Evolution of Molecular Photophysics

Abstract

A presentation is given, with retrospective commentary, on the experimental and theoretical contributions to key steps in the evolution of the framework of contemporary molecular photophysics from the Jabłoński Diagram to femtosecond range excitation phenomena. The distinctive features of polyatomic molecules separating their behavior from atomic and diatomic molecules are emphasized. Justification is given for the statement that spin-orbital coupling with its relativistic component commonly domi- nates the molecular excitation dynamics of light-(low-Z)-atom molecules.The paper deals with single-photon, single-molecule excitations. Some examples of single-photon, multi-molecule and multi-photon, single-molecule excitation phenomena are listed. A selection of these is made to illustrate the prevalence of femtosecond excitation modes.

Aminorhodamine (ARh): A Bichromophore with Three Emission Bands in Low Temperature Glasses

“…The first review of the fluorescent properties of xanthene‐type dyes appeared in 1897,7 describing xanthones, fluorescein, eosin and acridine. Since, the rhodamine and fluorescein chromophores have been adopted to excel in sensing and imaging,6, 8–21 and the general concepts of their molecular photophysics have been established 22–24…”

“…Since, the rhodamine and fluorescein chromophores have been adopted to excel in sensing and imaging, [6,[8][9][10][11][12][13][14][15][16][17][18][19][20][21] and the general concepts of their molecular photophysics have been established. [22][23][24] The photophysicso fr hodamine [25] have been extensively studied, partly to understand the fascinating fluorophore, and partly to enable the design of systems with increased fluorescenceq uantum yield. [3,[26][27][28][29][30][31][32][33][34][35][36][37] The results of these efforts are showcased by the Alexa dyes, that are close to perfect fluorochromes for imaging applications, [12] and by the many responsived yes developed based on fluorescein and rhodamine chromophores.…”

The Temperature Dependence of Fundamental Photophysical Properties of [Eu(MeOH-d4)9]3+ Solvates and [Eu.DOTA(MeOH-d4)]- Complexes

“…26,27 For a given electronic transition the rate constants of-or Einstein's coefficient for-spontaneous emission A is conveniently linked to the quantum mechanical transition dipole operator, which we in more loosely defined terms can link to the experimentally determined oscillator strength f. 28,29 The oscillator strength is a convenient measure as it provides a physical constant that can be used on any band, disregarding the number of lines present. 30 For Eu 3+ we can go a step further and use Arel as the emissive state is non-degenerate, see Figure 1. This allows us to experimentally determine transition probabilities and challenge the current theoretical models.…”

Modulating the Photochemistry of Bipyridylic Compounds by Symmetric Substitutions

“…Molecules undergoing excited-state intramolecular proton transfer (ESIPT) have attracted considerable attention in the recent years in connection with fundamental chemical and biological processes, [1][2][3][4] laser materials, [5][6][7] in information storage devices and optical switching, [8][9][10] and as polymer photostabilizers. [11,12] The apparent simplicity of the process is misleading, as in the excited state there are numerous processes (radiative and nonradiative) that may compete with the proton transfer, such as radiative emission (fluorescence) and internal rotations, which may lead to conical intersections or intersystem crossings.…”