214. Phthalocyanines. Part III. Preliminary experiments on the preparation of phthalocyanines from phthalonitrile

Abstract

As has been indicated (Part 11), o-phthalonitrile was not at first thoroughly investigated as a source of phthalocyanines because preliminary experiments with magnesium oxide, which yields a pigment with great facility when heated with o-cyanobenzamide, had shown no comparable reaction. Moreover, it was at first believed that the formation of pigment proceeded through the fixation of metal by an acidic hydrogen atom.In 1931, Heilbron and Irving directed our attention to the reaction between o-dibromobenzene, cuprous cyanide, and pyridine, first studied by de Diesbach and van der Weid (Helv. Chiwz. Acta, 1927, 10, SSS), who formulated the intensely blue, insoluble product as a complex pyridine salt, [C,H,(CN),,C,H,N],Cu.The same substance was also formed from phthalonitrile , cuprous bromide, and pyridine, and Heilbron and Irving suggested that it might in reality be a copper phthalocyanine. Furthermore, they showed that sodamide reacted with phthalonitrile in quinoline at 150" to yield some 15% of a substance resembling metal-free phthalocyanine in properties. We are greatly indebted to Professor Heilbron for communicating these facts to us.We find that many metals and metallic derivatives react with phthalonitrile to yield compounds of the phthalocyanine type. The reaction is generally more ready with the nitrile than with o-cyanobenzamide, but magnesium oxide and antimony are exceptions in this respect. In the most favourable cases the reaction proceeds with considerable evolution of heat : it may become uncontrollable when large quantities of reagents are used. The temperature necessary to start the reaction varies from 135" to the boiling point of the nitrile (294") according to the nature of the metal and its availability (see p. 1027). A general examination of the capacity of metals for combination with phthalonitrile is in progress, but the results of preliminary work may be classified as follows :

Current status of phthalocyanines in the photodynamic therapy of cancer

“…As such, starting in 1929, Linstead and his group began their work on phthalocyanines which lead to the determination of their structure in the early 1930s [38][39][40]. The synthesis of Pcs [41][42][43] and their relationship to porphyrins [44], along with further examination into the intricate structure of Pcs [43], their planar nature, their complexes with metal ions [40,43,45,46] and their stability [38,43] were subsequently studied. The structure of phthalocyanines was later confirmed by Robertson via X-ray crystallography in a series of classic papers [47][48][49][50].…”

Ground and excited states of zinc phthalocyanine, zinc tetrabenzoporphyrin, and azaporphyrin analogs using DFT and TDDFT with Franck-Condon analysis

“…[1][2][3] Since then, MPcs have been studied for use in chemical sensors, photodynamic therapy, optics, bioelectronics, molecular optoelectronic gates, and molecular neural networks. [4][5][6][7] Of particular importance is their application in organic semiconductors, discovered in 1948 by Eley.…”

Facile synthesis of phthalocyanine at low temperature with diisopropylamide anion as nucleophile

“…Thus far, most of phthalocyanine and their derivatives were prepared by condensation of phthalonitriles with lithium n-petanolate or DBU in refluxing pentanol, or by fusion methods from phthalic anhydrides or its derivatives. [6][7][8][9][10][11][12][13][14][15][16] These reactions were performed at a high temperature (100 ~ 300 °C) making them not only energy-but also time-consuming. Moreover, reactions of phthalonitrile with thermal sensitive substituents are always unfavorable at high temperature.…”