Tetrakis(diethyl phosphonate)-, tetrakis(ethyl phenylphosphinate)-, and tetrakis(diphenylphosphine oxide)-substituierte phthalocyanines

The title compounds 7, 9, and 11 are obtained by tetramerization of diethyl (3,4-dicyanophenyl)phosphonate (5), ethyl (3,4-dicyanophenyl)phenylphosphinate (8), and 4-(diphenylphosphinyl)benzene-1,2-dicarbonitrile (10). The P-31-NMR spectra of the phthalocyanines 7, 9, and 11 and of their metal complexes present five to eight signals confirming the formation of four constitutional isomers with the expected C-4h, D-2h, C-2v, and C-s symmetry. In the FAB-MS of the Zn, Cu, and Ni complexes of 7 and 9, the peaks of dimeric phthalocyanines are observed. By gel-permeation chromatography, the monomeric complex [Ni(7)] and a dimer [Ni(7)12] can be separated. These dimers differ from the known phthalocyanine dimers, i.e., possibly the P(O)(OEt)(2) and P(O)(Ph)(OEt) substituents in 7 and 9 are involved in complexation. The free phosphonic acid complex [Zn(12)] and [Cu(12)] are H2O-soluble. In the FAB-MS of [Zn(12)], only the peaks of the dimer are present; the ESI-MS confirms the existence of the dimer and the metal-free dimer. In the UV/VIS spectrum of [Zn(12)], the hypsochromic shift characteristic for the known type of dimers from 660-700 nm to 620-640 nm is observed. As in the FAB-MS of [Zn(12)], the free phosphinic acid complex [Zn(13)] shows only the monomer, an ESI-MS cannot be obtained for solubility problems. The UV/VIS spectrum of [Zn(13)] demonstrates the existence of the monomer as well as of the dimer.