Gold(iii) tetraarylporphyrin amino acid derivatives: ligand or metal centred redox chemistry?† †Electronic supplementary information (ESI) available: NMR and IR spectra, spectral changes upon reduction of [Au(TPP)][PF6], [4a][PF6], [4b][PF6], [4c][P

Gold(iii) tetraarylporphyrin amino acid derivatives: ligand or metal centred redox chemistry?† †Electronic supplementary information (ESI) available: NMR and IR spectra, spectral changes upon reduction of [Au(TPP)][PF6], [4a][PF6], [4b][PF6], [4c][P