Separation of structural isomers of tetra-tert-butylphthalocyaninatonickel(II)

Abstract

Tetra-tert-butylphthalocyaninatonickel is synthesized from phthalic anhydride as well as from phthalodinitrile and nickel chloride, whereby a mixture of four different structural isomers are obtained; two of these isomers, with C2"and C,-symmetry are isolated for the first time by HPLC and medium pressure liquid chromatography (MPLC) and characterized.

Synthesis and Isolation of 2,9,17,23-Tetrakis[(3,5-dimethyl-1H-pyrazol-1-yl)phenoxy]phthalocyanine and Its Magnesium(II) and Zinc(II) Complexes

“…The symmetry of regioisomer can be determined by the number of signals in 1 H NMR spectrum. [43][44][45] In the case C 4h and D 2h regioisomers all isoindole fragments with substituents R (A, B, C, D) are magnetically equivalent and the 1 H NMR spectra of these regioisomers must be similar to spectrum of corresponding substituted phthalonitrile. The C 2v regioisomer contains magnetically equivalent (A, D) and (B, C) pairs of isoindole fragments but these pairs are magnetically nonequivalent among themselves and 1 H NMR spectrum of this regioisomer must contain two signals with equal intensity of each proton of isoindole fragments with substituent R. In the case of C S regioisomer all isoindole fragments with substituent R (A, B, C, D) are magnetically nonequivalent and 1 H NMR spectrum of this regioisomer …”

“…[41][42][43] In order to prevent aggregation, the 1 H NMR spectra of phthalocyanines 2-4 were recorded in dilute solutions (0.5 mg per 1 mL). The 1 H NMR spectra of magnesium phthalocyanines 3 and zinc phthalocyanine 4 practically do not differ from each other.…”

“…The separation of the mixture of the four regioisomers by column chromatography is highly challenging [40] and was achieved by preparative thin layer chromatography or HPLC with chiral column. [41][42][43][44][45][46] It is known that due to the presence of bulky substitutients, a pure regioisomer of 3-substituted ZnPc can be isolated by column chromatograpy. So, the one C 4h isomer of non-peripheral 3-(alkylaryloxy)-tetrasubstituted phthalocyanine was isolated by column chromatography in high yield.…”

Synthesis of substituted phthalocyanines

“…In 1993, Hanack reported successful separation of C 2v and C s isomers of nickel 2,9(10), 16(17),23(24)-tetra-tert-butyl phthalocyanine using direct phase HPLC and MPLC methods. 43 Eight years later, the isomer distribution in metal-free 2,9(10), 16(17),23(24)-tetraethyl-and In(C 6 H 4 CF 3 -p) 2,9(10), 16(17),23(24)-tetra-tert-butylphthalocyanines was tested by the same research group. 44 The peak area for 'C 4h ' (C 4 ) and 'D 2h ' (D 2 ) isomers was found to be the same as predicted by statistics for the cyclotetramerization reaction, while the combined area for the 'C 2v ' (C 2 )/ C s isomers is expected to be 75%.…”

Glycosylated Metal Phthalocyanines

“…( Figure 2) by tetramerization of e.g., 3-substituted phthalonitriles. Separation of the isomers of substituted Pc was first achieved by Hanack and coworkers using high-performance liquid chromatography (HPLC) [3,5].…”