N-Confused porphyrins: complexation and ¹H NMR studies

Abstract

The complexation of 2-aza-21-carba-tetraphenylporphyrin and 2-aza-2-methyl-5,10,15,20-tetraphenyl-21-carbaporphyrin with nickel and zinc acetates in organic solvents has been investigated by UV-Vis spectroscopy and 1H NMR.

Photophysical study and in vitro approach against Leishmania panamensis of dicloro-5,10,15,20-tetrakis(4-bromophenyl)porphyrinato Sn(IV)

“…23 The porphyrins and their metallic-derivatives act efficiently as sensitizing agents and they have presented phototoxic activity against different pathogens, such as bacteria, fungi, viruses and parasites. [24][25][26][27] Different porphyrinic photosensitizers have reported antileishmanicidal activity against Leishmania tarentolae in promastigote stage (ethyl and diethyl carbaporphyrin), against amastigotes of L. panamensis, and promastigotes of L. major and L. braziliensis (β-substituted porphyrinic systems). [28][29][30][31][32] Improved pharmacological responses have been found when incorporating metals in the macrocycle, as reported by Gomes et al when evaluating the activity against L. amazonensis against derivatives metalated with Bi (III) and Sb (IV) (IC50 of 93.8 μM and 52.4 μM respective).…”

Photophysical study and in vitro approach against Leishmania panamensis of dicloro-5,10,15,20-tetrakis(4-bromophenyl)porphyrinato Sn(IV)

“…23 The porphyrins and their metallicderivatives act efficiently as sensitizing agents and they have presented phototoxic activity against different pathogens, such as bacteria, fungi, viruses and parasites. [24][25][26][27] Different porphyrinic photosensitizers have reported anti-leishmanicidal activity against Leishmania tarentolae in promastigote stage (ethyl and diethyl carbaporphyrin), against amastigotes of L. panamensis, and promastigotes of L. major and L. braziliensis (β-substituted porphyrinic systems). [28][29][30][31][32] Improved pharmacological responses have been found when incorporating metals in the macrocycle, as reported by Gomes et al when evaluating the activity against L. amazonensis against derivatives metalated with Bi (III) and Sb (IV) (IC50 of 93.8 μM and 52.4 μM respective).…”

NH Tautomerism of N-Confused Porphyrin: Solvent/Substituent Effects and Isomerization Mechanism

“…In solution, the tautomeric equilibrium of 2-2H and 2-3H is controlled mainly by the solvent, and the color of the solution changes significantly depending on the solvent used, reflecting the difference in the electronic states of the two tautomers. − For example, in nonpolar solvents such as chloroform, N-confused tetraphenylporphyrin (NCTPP, 2a in Figure ) shows the red color of the inner 3H form ( 2-3H ), which is the most stable and aromatic among the possible tautomeric forms identified by theoretical calculations. − In contrast, in polar and proton-accepting solvents such as N , N -dimethylformamide (DMF), NCTPP shows the green color of the inner 2H form ( 2-2H ), in which the aromatic circuit is incomplete because of the cross-conjugation at the confused pyrrole ring. This characteristic bistability of NCP may be potentially applicable in optical switches or molecular sensors. , Indeed, attempts to apply this system to the sensing of humidity and anions , as well as isomerization-coupled switching have been reported …”