fotochimiei

Fotochimia is the branch of chemistry concerned with the chemical reactions that are initiated by the absorption of light. These reactions are often referred to as photochemical reactions. The fundamental principle is that light energy is absorbed by a molecule, which then becomes excited to a higher energy state. This excited state can then undergo chemical transformations that might not be possible under normal thermal conditions. The absorbed energy must be sufficient to overcome the activation energy barrier of the reaction. Key concepts in fotochimia include quantum yield, which is the ratio of the number of reacting molecules to the number of photons absorbed, and photosensitization, where a molecule absorbs light and then transfers its energy to another molecule, initiating a reaction in the latter.

Fotochimia has numerous applications across various fields. In photosynthesis, plants use light energy to convert carbon dioxide and water into glucose and oxygen, a crucial process for life on Earth. The degradation of many organic materials by sunlight is also a photochemical process. Industries utilize fotochimia for processes like photopolymerization, used in 3D printing and coatings, and in the production of certain pharmaceuticals and fine chemicals. Understanding and controlling photochemical reactions allows for the development of new materials and more efficient chemical synthesis methods.