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16 Μαρ 2023 · To consider what happens in the process of fluorescence, we need to think of the possible energy states for a ground and excited state system. Draw an energy level diagram for a typical organic compound with \(\pi\) and \(\pi\) * orbitals.
26 Ιουν 2022 · The excited state can be considered a new chemical species with characteristics and mainly its reactivity different from the ground state due to the great energy accumulated in the process of formation of the excited state.
1 Ιαν 2014 · In a typical closed-shell ground-state molecule, the reaction usually begins on the potential energy surface of the excited state (S 1 or higher) at the Franck–Condon geometry (i.e., at the ground-state equilibrium geometry) and evolves either to the S 1 state minimum, from which it might emit, or to a crossing region with the ground state.
In quantum mechanics, an excited state of a system (such as an atom, molecule or nucleus) is any quantum state of the system that has a higher energy than the ground state (that is, more energy than the absolute minimum).
Where UV-vis spectroscopy becomes useful to most organic and biological chemists is in the study of molecules with conjugated \(\pi\) systems. In these groups, the energy gap for π - π * transitions is smaller than for isolated double bonds, and thus the wavelength absorbed is longer.
1 Ιαν 2011 · Central to any understanding of photochemistry is the concept that molecular systems possess well-defined electronic states: ordinary (thermal) chemistry is the chemistry of the ground electronic state, while photochemistry is the chemistry of (or originating from) electronic excited states.
8 Αυγ 2018 · The competition between these processes determines the fate of an electronically excited system—some emit light back, some effectively convert excess electronic energy into heat, some produce charge carriers, and some change their chemical identity.
