protonic

Protonic is an adjective describing anything related to protons, the positively charged subatomic particles in atomic nuclei. In chemistry and related fields, the term is often used for processes and media in which protons are transferred or conducted between species or through a substance.

In acid–base chemistry, proton transfer is central. Substances that donate protons are described as protonic or Brønsted–Lowry acids, with their conjugate bases acting as proton receivers. The protonic character of a system is influenced by pH, and the protonation state of molecules—such as amino acids, nucleotides, and organic ligands—can determine reactivity, structure, and function.

Protonic conduction refers to the movement of protons through a medium. In liquids, protons can move via mechanisms like the Grotthuss mechanism, involving rapid transfer along a network of hydrogen bonds. In solid electrolytes, protons can hop between sites within a lattice or along defect pathways. Protonic conductors are important in technologies such as fuel cells, certain sensors, and electrochemical devices, with examples including hydrated oxides and specialized polymer membranes.

Historically, the term derives from the proton, a fundamental particle long central to physics and chemistry. Today, protonic terminology emphasizes proton transfer and transport phenomena, spanning chemical reactivity, materials science, and energy applications, while remaining distinct from but related to general nuclear or particle physics contexts.