Synthesis, spectral and mesomorphic properties of octa-alkoxy substituted phthalocyanine ligands and lanthanide complexes

Abstract

By functionalizing the phthalocyanine Pc ring with long aliphatic chains, liquid-crystalline compounds can be obtained. In order to investigate the influence of chain length on mesophase behaviour, we prepared a series of homologous peripherally octa-alkoxy substituted phthalocyanines. The alkoxy chain length was varied from CH O to C H O. Trivalent lanthanide ions form with 3 2 0 4 1 phthalocyanine ligand complexes of the type Pc Ln, where the lanthanide ion is sandwiched between two phthalocyanine rings. Hitherto, 2 Ž. most of the mesomorphic Pc Ln complexes described in literature have Lu III as the central metal ion. We prepared lanthanide 2 complexes of peripheral octa-alkoxy substituted phthalocyanines in order to investigate the influence of lanthanide ion on thermal behaviour. The thermal properties of ligands and complexes were investigated by hot-stage polarising optical microscopy and by Ž. differential scanning calorimetry DSC. The metallomesogens exhibit a columnar mesophase. Solution absorption and MCD spectra were also investigated.

Electrical and gas sensing properties of novel cobalt(II), copper(II), manganese(III) phthalocyanines carrying ethyl 7-oxy-4,8-dimethylcoumarin-3-propanoate moieties

“…Therefore, the combination of coumarin and Pc functional groups into a single hybrid compound via a suitable synthetic methodology is expected to produce highly functional compounds with intriguing physicochemical properties. On the other hand, phthalocyanines (Pcs) form an important class of macrocyclic compounds that do not occur in nature [11]. Following their first synthesis in 1907, they have been firmly established as blue and green dyes [12] and enjoy widespread usage in diverse areas such as gas and chemical sensors [13][14][15], electrochromic devices [16], non-linear optics [17,18], liquid crystals, Langmuir-Blodgett films and substituted derivatives, which can also be used for photodynamic cancer therapy and other processes driven by visible light [19][20][21].…”

Liquid‐Crystalline Ternary Rare‐Earth Complexes

“…In the last decade, there has been considerable activity in the research field of lanthanide-containing liquid crystals (which are also called lanthanidomesogens). [2,[9][10][11] Different types of ligands were used to design new classes of lanthanidomesogens: Schiff bases, [12][13][14][15][16][17][18][19][20][21][22] β-enamino ketones, [23] alkanoates, [24,25] 4-alkoxybenzoates, [26][27][28] phthalocyanines, [29,[29][30][31][32][33] porphyrins, [34,35] imidazo [4,5-f] [1,10]phenanthrolines, [36] β-diketonates, [37] crown ethers, [38][39][40] 2,6-bis-(benzimidazol-2Ј-yl)pyridines, [11,41,42] and polyoxometalatesurfactant complexes. [43] Most examples of lanthanidomesogens are thermotropic liquid crystals, although some examples of lyotropic lanthanidomesogens have also been reported.…”

Liquid-crystalline metallophthalocyanines containing late first-row transition metals

“…The phthalonitriles were prepared via a three stepreaction, consisting of alkylation of catechol via a Williamson etherification reaction, secondly dibromination of the 1,2-dialkoxybenzenes and finally substitution of the bromine atoms by cyano groups via a Rosenmund-Von Braun reaction. 10,12 The template reaction consists of a reaction of the phthalonitrile with 1/4 equivalent transition metal chloride salt in the presence of ½ equivalent of DBU in 2-(dimethylamino)ethanol. After a reaction time of 48 hours, the mixture was dissolved in a minimum amount of chloroform and the product was precipitated in acetone and filtered.…”