atom-transfer radical polymerization

initialism: ATRP
https://doi.org/10.1351/goldbook.08924
Reversible-deactivation radical polymerization in which the deactivation of the radicals involves reversible atom-transfer or reversible group transfer to usually, though not exclusively, transition-metal complexes.
Notes:
  1. The activator is often incorrectly termed a catalyst. The term catalyst should only be used when referring to a species which is not changed as a consequence of reaction.
  2. There are various forms of ATRP that differ in details of the intimate mechanism, the reaction conditions and/or the reagents used. These include:
    1. Conventional, traditional or normal ATRP where the initial reaction mixture comprises an initiator (typically an alkyl halide) and an activator (the species on right-hand side of Figure).
    2. Reverse ATRP where the initial reaction mixture comprises a conventional initiator as a source of radicals (e.g., a dialkyldiazene or a peroxide) and a deactivator (the species on left hand side of Figure).
    3. AGET-ATRP (Activator Generated by Electron Transfer) where the activator is generated in situ by an electron transfer from a reducing agent at the commencement of the polymerization.
    4. ARGET-ATRP (Activator ReGenerated by Electron Transfer) where the activator is continuously regenerated by electron transfer from a reducing agent.
    5. lICAR-ATRP (Initiators for Continuous Activator Regeneration) - ARGET-ATRP where the reducing agent is a radical derived from a conventional initiator (e.g., a dialkyldiazene).
    6. SARA-ATRP (Supplemental Activators and Reducing Agents) where the polymerization commences with the activator (e.g., a zero-valent metal or an inorganic sulfite) which is a both a supplemental activator and a reducing agent for the deactivator.
    7. eATRP (electrochemically-mediated ATRP) where the activator is continuously regenerated by electrical current.
    8. photoATRP (photochemically-mediated ATRP) where the activator is continuously regenerated by photoreduction. The reduction can be facilitated by the presence of electron donors.
    9. mechanoATRP (mechanically-mediated ATRP) where the activator is continuously regenerated by mechanical forces through the use of the piezoelectric effect or ultrasound.
    10. PET-ATRP (photoinduced electron transfer ATRP) where activation involves electron-transfer from a photo-excited activator to an initiator which then dissociates to give an initiating species.
    11. O-ATRP (organic ATRP), a form of PET-ATRP where the activator is an organic photoredox catalyst.
  3. The term ATRP (unqualified) usually refers to copper-mediated ISET-ATRP.
Source:
PAC, 2022, 94, 1093. (Terminology for chain polymerization (IUPAC Recommendations 2021)) on page 1109 [Terms] [Paper]