Tetramethylammonium perchlorate (TMAP), with the chemical formula (CH3)4NClO4, is a chemical compound composed of tetramethylammonium ions (TMA+) and perchlorate ions (ClO4^-). It is a white crystalline solid that is highly soluble in water.

Tetramethylammonium perchlorate is commonly used in chemistry and research laboratories as a phase-transfer catalyst and as a source of perchlorate ions. Some key properties and uses of TMAP include:

1. Phase-Transfer Catalyst: TMAP is used as a phase-transfer catalyst in organic synthesis. It facilitates the transfer of reactants between two immiscible phases, such as an aqueous and organic phase, by forming a complex with the reactants and enabling their transport across the phases.
2. Perchlorate Source: TMAP is used to introduce perchlorate ions into various chemical reactions and processes.
3. Ion-Exchange Resin Regeneration: In some cases, TMAP is used to regenerate ion-exchange resins used for water purification and chemical separations.
4. Electrolyte for Batteries: TMAP has been investigated for potential use as an electrolyte in certain types of batteries.

Tetramethylammonium perchlorate is considered safe when handled properly in a laboratory setting. However, it is essential to use appropriate safety precautions, such as good ventilation and the use of personal protective equipment, when working with any chemicals. Additionally, due to its potential use in the synthesis of hazardous materials, access to TMAP may be regulated in some regions to prevent misuse or unsafe practices.