Answer to Question #115538 in Physical Chemistry for DEEPAK SINGH

Question

which of the following are the reactions in which molecules absorbing light do not themselves react but induace other molecules to react? (a) free radical reactions (b) chain reaction (c) reversible reactions (d) photosensitized reactions.

Answer 1

Answer: The photosensitized reactions are the reactions in which molecules absorbing light do not themselves react but induce other molecules to react.

The photosensitiser is a molecule that absorbs light and transfers the energy of light to other molecules directly (via an energy transfer, e.g. triplet states generation in organic molecules, [Ru]^T to anthracene) or via the chemical reactions (e.g. redox reactions, where photosensitiser acts as acceptor or as donor of electrons), with regeneration of the photosensitiser in the cycle. The light harvesting by a photosensitiser leads to the formation of the excited state of the photosensitizer that is quenched after.