History of Phthalocyanine: Phthalocyanine which is not found in nature is derived from the Greek term for naphtha ( rock oil) and cyanine ( dark blue) [1]. The name was first used by Prof Reginald Linstead of the Imperial College Industry. It’s used as a colorant agent in industry because it’s cheap, robust and has an intense absorption at long wavelength of the visible spectrum. The compound was accidentally discovered in 1907 by Braun and Tcherniac who recorded a highly coloured compound after heating ortho-cyanobenzamide at high temperature. [2,3] In 1927 Diesbach and Von der Weild of Fribourg University, carried out a reflex reaction using ortho-dibromobenzene with cyanide and obtained a blue coloured compound with 23% yield. In 1928 at the Grangemouth plant of Scottish Dyes Ltd a blue-green impurity has formed inside the reaction vessel during the …show more content…
Isoindoline is a heterocyclic organic compound with the molecular formula C₈H₉N and Phthalocyanine has a molecular formula of C32H18N8. Phthalocyanine is part of tetra-pyrollic family and it has nitrogen in all meso-positions[3]. As mentioned before the compound has planar structure with an 18 π-electron system as predicted by Erich Hückel’s theory of aromaticity. The compound has four benzenes with 16 reactive sites because of this aromaticity and the covalent coordination of the central metal the compound is stable. So far, over 5000 of Phthalocyanine compounds have been prepared.[1] Thousands of tons of Phthalocyanine is produced annually, and used as colouring agent in photographic, plastics, printing and textile industries.[2] Copper Phthalocyanine is the most commonly used colorant in manufacturing as it gives more distinct shade.