Phthalocyanine formation using metals in primary alcohols at room temperature

Abstract

Lithium metal added to a solution of 4-neopentoxyphthalonitrile in 1-octanol or other long-chain primary alcohols at room temperature resulted in phthalocyanine formation at a reasonable rate in good yield, while preformed lithium l-octanolate under the same conditions gave 2,9,16,23-tetraneopentoxyphthalocyanine, but in lower yield at a slower rate. The use of lower-molecular-weight alcohols slowly gave a phthalocyanine in lower yields. Reverse micelle formation when using long-chain alcohols is proposed as a possibility for enhanced phthalocyanine formation at room temperatue. 2,9,16,23-Tetasubstituted phthalocyanines and metallated phthalocyanines were prepared at room temperature from 4-neopentoxyphthalonitrile, 4-bis(4-methoxyphenyl)methoxyphthalonitdle, 4-[-(4-ethoxy-3-methoxyphenyl)-l-phenyl]methoxyphthalonitrile and phthalonitrile using lithium l-octanolate in l-octanol or by the addition, to a solution of the phthalonitrile in ethanol, of calcium turnings or, to a solution of the phthalonitrile in methanol, of magnesium, zinc, iron or copper powder. The tetrasubstituted phthalocyanines produced exhibited a nonstatistical distribution of regioisomers, indicating that electronic effects become important in room-temperature cyclotetramerization of phthalonitriles to phthalocyanines. Copyright O 2000 John Wiley & Sons, Ltd. KBYWORDSz 2,9,16,23-tetrakis[bis(4-methoxyphenyl)methoxy]phthalocyaninato zinc(Il); 2,9,16,23-tetrakis[ 1-(4-ethoxy-3-methoxyphenyl)-I-phenyl]methoxyphthalocyaninato zinc(Il); metal catalysis

Use of elemental metals in different grade of activation for phthalocyanine preparation

“…The recent article [6] should be especially mentioned, in which softest conditions for Pc obtaining were offered. A series of primary alcohols and elemental metals were used for the condensation of phthalonitriles at room temperature.…”

“…It was proposed that ''more activated forms of some metals are required''. In this respect, at low temperatures an additional ''impulse'' is needed for the cyclization process; precisely, surface energy of strong base (solid CH 3 ONa) [4] or extra energy of defects in the surface of elemental metals [6] could serve as such an impulse to reach the energetic barrier. So, any source of additional energy could be useful for successful synthesis at low temperatures.…”

Copper 2,9(10),16(17),23(24)-and 1,8(11),15(18),22(25)-tetra-(4-carboxyphenoxy)phthalocyanines and their esters: The synthesis and liquid-crystalline properties

“…15,20,21 This type of phthalocyanines has found applications as pH sensitive dyes, 12 photosensitizers for photodynamic therapy of cancer, 13,14 catalysts for fuel cells and solar cells, 14 and in other fields of science and tech nology. 11, [15][16][17][18][19] Carboxy substituted phthalocyanines were used as the starting compounds in the synthesis of corresponding es ters that are characterized by high solubility in organic solvents 6,7,22,23 and possess both thermotropic and lyo tropic mesomorphism. 6, 7 Based on the aforesaid, interest in the compounds combining the properties of aryloxy and carboxy substi tuted metal phthalocyanines is quite understandable.…”

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

“…[17][18][19][20][21][22] However, these procedures require excess base (several to ten-fold excess), 18 prolonged reaction time (hours, days or even weeks), [17][18][19] or have to be performed with the help of ultrasonic treatments, irradiation or electrolysis. [20][21][22] It is still a challenge to develop a low temperature method to produce phthalocyanine in a facile and reactant-saving way.…”