Tetrasodium-Meso-Tetra (4-Sulfonatophenyl) Porphine

[O-]S (=O) (C1=CC=C (/C2=C3C=CC (/C (C4=CC=C (S ([O-]) (=O) =O) C=C4) =C5N/C (C=C\5) =C (C6=CC=C (S ([O-]) (=O) =O) C=C6) \C7=N/C (C=C7) =C (C8=CC=C (S ([O-]) (=O) =O) C=C8) \C9=CC=C2N9) =N\3) C=C1) =O.[Na+].[Na+].[Na+].[Na+]