Phthalocyanines with bulky ester substituents

Abstract

Pd(II), Co(II), Cu(II) and Zn(II) phthalocyanines (2-5) with a tricarbethoxyethyl substituenl on each benzo group was prepared from 4-(1,1,2-tricarbethoxyethyl)-phthalonitrile (1) and the corresponding divalent metal salt at 170 °C. Transesterification occurred when the reaction was carried out in pentanol as in 6. Treatment of 2 with sodium ethoxide at room temperature and further acidification resulted with tetra(I,2-(dicarboxyethyl)phthalocyaninatopalladium (7). The UV-Vis spectrum of 7 in aqueous solution indicated that at pH a 12 dimeric and monomeric species, but at pH $approx$ 6 only dimeric form were present. Phthalocyanines with four naphthyl-malonic ester groups on the periphery (9-11) were synthesized by cyclotetramerization of 4-(l,l-dicarbethoxy-2-naphthyl-ethyl)-phthalonitrile(8). As a natural consequence of single substiluent on each benzo group, the phthalocyanines (2-7) and (9-11) are all a mixture of four constitutional isomers. The new compounds were characterized by elemental analyses, FT-IR, NMR, UV- Vis and MASS spectral data. The electronic spectra of (9-11) exhibit an intense $pi-pi^{ast}$ transitions of naphthyl identity together with characteristic Q and B bands of the phthalocyanine core. NMR investigations of compound 2 and 5 provided the characteristic chemical shifts for the structures expected. At the first glance, the general appearance of these two spectra with sharp peaks clearly showed the effect of bulky substituents which hindered aggregation encountered at high concentrations used in NMR spectra.

Özet

Trikarbeloksietil ve naftil-malonik ester sübstitüe ftalosiyaninler, dietil-(3,4-disiyanofenil)malonat' in potasyum tuzu ile bromoasetikasit etil esteri ve I-(klorometil)naftalin 'in reaksiyonu sonucu hazırlanmış yeni iki farklı ftalonitril türevi ile ilgili metal tuzlarının reaksiyonu sonucu elde edilmiştir. 2,9,17,23-Tetra-((1,1,2-(trikarhetoksi-etil))-ftalosiyaninato palladyum (II) (2) bileşiğinin hidrolizi sonucu süksinik asit sübstitüe ftalosiyanin türevi hazırlanmıştır. Bu bileşiğin su içerisinde farklı pH'larda alınan UV-Vis spektrumunda pH $approx$ 12' de monomerik ve dimerik türlerin her ikisinin de olduğu pH $approx$ 6' da ise bir tek dimerik türün bulunduğu gözlenmiştir. Ayrıca 1 bileşiğinin DBU varlığında pentanol içerisinde siklotetramerizasyonu sonucu transesterifikasyona uğramış metalsiz ftalosiyanin türevi elde edilmiştir. Sentezlenen yeni bileşiklerin yapısı elementel analiz, FT-IR, UV-Vis, EI-MS, FAB-MS, $^1H$-NMR, $^{I3}C$-NMR yöntemleri ile aydınlatılmıştır.