PMDETA

PMDETA, short for N,N,N',N'',N''-pentamethyldiethylenetriamine, is a tertiary polyamine widely used as a coordinating ligand for transition metals. It is derived from diethylenetriamine by exhaustive methylation, resulting in a flexible, sterically hindered ligand with five methyl substituents distributed among three nitrogen atoms. The molecule is typically a colorless to pale yellow liquid that is miscible with water and many organic solvents, and it exhibits strong basic and coordinating properties.

In coordination chemistry and catalysis, PMDETA forms stable complexes with copper(I) and other metals. The Cu(I)-PMDETA complex is a common catalytic species in copper-mediated processes, where it facilitates electron transfer and stabilizes reactive intermediates. The ligand’s steric bulk and electron-donating character can enhance catalyst performance by improving activity, control, and tolerance to functional groups.

A primary application of PMDETA is in atom transfer radical polymerization (ATRP). When used with copper halides, PMDETA enables living or controlled polymerization that can produce polymers with defined molecular weights and narrow dispersities. This system supports a wide range of monomers and solvents, including aqueous and polar organic media, expanding the versatility of ATRP. PMDETA is also encountered in other copper-catalyzed transformations, including certain azide–alkyne cycloadditions, where it helps to stabilize the copper center and promote catalytic efficiency.

Safety and handling: PMDETA is a caustic, corrosive amine and should be handled with appropriate personal protective equipment in a well-ventilated area. Avoid skin and eye contact and inhalation of vapors.