What is Photostationary equilibrium?

The photostationary state of a reversible photochemical reaction is the equilibrium chemical composition under a specific kind of electromagnetic irradiation (usually a single wavelength of visible or UV radiation).

Is photolysis an oxidation?

Photolysis during photosynthesis occurs in a series of light-driven oxidation events. The energized electron (exciton) of P680 is captured by a primary electron acceptor of the photosynthetic electron transport chain and thus exits photosystem II.

What is photosensitized reaction?

A reaction is considered photosensitized when an excited molecule (the donor or photosensitizer) induces photochemical reactions in molecules (the acceptor or quencher) that are not photochemically reactive by themselves, i.e., do not absorb light in the considered wavelength range.

What is meant by quantum yield?

Quantum yield (Φ) is defined as the ratio of the number of photons emitted to the number of photons absorbed. Notably, quantum yield is independent of instrument settings and describes how efficiently a fluorophore converts the excitation light into fluorescence.

What is called photolysis?

Photolysis (also called photodissociation and photodecomposition) is a chemical reaction in which an inorganic chemical (or an organic chemical) is broken down by photons and is the interaction of one or more photons with one target molecule.

What is oil photooxidation?

Photo-oxidation can change the composition of an oil. 15-18. It occurs when the sun’s action on an oil slick causes oxygen and carbons to combine and form new products that may be resins. The resins may be somewhat soluble and dissolve into the water, or they may cause water-in-oil emulsions to form.

What is photosensitized reaction and photosensitizer?

What are photosensitizers explain photosensitized reaction *?

In Type I photosensitized reactions, the photosensitizer is excited by a light source into a triplet state. The excited, triplet state photosensitizer then reacts with a substrate molecule which is not molecular oxygen to both form a product and reform the photosensitizer.

What is the difference between quantum yield and quantum efficiency?

Please note that quantum yield refers to events/photons emitted per events/photons absorbed while quantum efficiency refers to energy, i.e. energy out/energy in.

What is Stark-Einstein law?

The second law of photochemistry, the Stark-Einstein law, states that for each photon of light absorbed by a chemical system, only one molecule is activated for subsequent reaction. This “photoequivalence law” was derived by Albert Einstein during his development of the quantum (photon) theory of light.

What gas is produced by photolysis?

The layer of ozone is formed by the process of photolysis or photodissociation. In the stratosphere, ozone is formed by the striking oxygen molecule having two oxygen atoms O2 with ultraviolet light. It splits O2 into an individual oxygen atom which is known as atomic oxygen.

What is photolysis formula?

The initiation reaction to form hydroxyl radical is dependent on the absorption of UV energy by H2O2 and the efficiency of the photochemical reaction. The direct UV photolysis of H2O2 is described by the following general reaction: [44b]H2O2+hν→2•OH.