Enhanced Electrogenerated Chemiluminescence of Phenylethynylpyrene Derivatives: Use of Weakly Electron-Donating Group as a Substituent

A weakly donating group (n-propyl) has
been used
as a substituent at the para-position of the phenyl
group for a series of phenylethynylpyrene derivatives where the number
of phenylethynyl peripheral arms appended to the pyrene core is varied.
This system markedly improved the concurrent stability of both cation
and anion radicals and consequently greatly improved electrogenerated
chemiluminescence (ECL). Density functional theory (DFT)-based theoretical
calculations supported the associated photophysical and electrochemical
properties of the series compounds.