[thal-uh-sahy-uh-neen, -nin, fthal-]
noun Chemistry.
  1. Also called metal-free phthalocyanine. a blue-green pigment, C32H18N8, derived from phthalic anhydride.
  2. any of the group of blue or green pigments produced by the interaction of metal-free phthalocyanine and a metal, especially copper: used chiefly in the manufacture of enamels, printing inks, and automotive finishes.

Origin of phthalocyanine

First recorded in 1930–35; (na)phthal(ene) + -o- + cyanine Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

British Dictionary definitions for phthalocyanine


  1. a cyclic blue-green organic pigment. Formula: (C 6 H 4 C 2 N) 4 N 4 H 4
  2. any of a class of compounds derived by coordination of this compound with a metal atom. They are blue or green pigments used in printing inks, plastics, and enamels

Word Origin for phthalocyanine

C20: from phthal- (see phthalein) + cyanine
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

phthalocyanine in Medicine


  1. Any of several stable, light-fast, blue or green organic pigments used in enamels and plastics.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.