mechanochemistry

Mechanochemistry is the initiation of chemical reactions by solid-state mechanical means. Mechanochemistry thus represents a fourth way to cause chemical reactions, complementing thermal reactions in fluids, photochemistry, and electrochemistry. Mechanochemistry focuses on the transformations of covalent bonds by mechanical force. Not covered by the topic are many phenomena: phase transitions, dynamics of biomolecules, and sonochemistry. Mechanochemistry also encompasses mechanophores which are molecules that undergo predictable changes in response to applied stress. Two types of mechanophores are mechanochromic ones in which a force causes a change in molecular structure and subsequently color and acid releasing mechanophores that release small amounts of an acid such as HCl in response to an applied force.