EPR Spectroscopy Investigation of Cu²⁺ Ions Adsorbed in Tannin-Formaldehyde Resins of Mimosa (Acacia mearnsii) Bark Extracts

Scheme 1

Combinations of resorcinol and phloroglucinol with catechol and pyrogallol afford the tanning substances present in Acacia mearnsii bark extracts.