Effects of Core and/or Peripheral Protonation of meso-Tetra(2-, 3-, and 4-pyridyl)Porphyrin and meso-Tetra(3-methylpyridyl)Porphyrin on Their UV-vis Spectra

Table 2

UV-vis spectral data for the interaction of H₂t(py)P with HCl in CH₂Cl₂^a.

Porphyrins and the dications	Soret band	Q(0,0) band
	(λ/nm)	(λ/nm)
H2t(2-py)P	417.0	642.0
[H4t(2-py)P](Cl)2	471.3	662.2
Δν (cm^−1)	−2762.9	−475.2
H2t(3-py)P	418.0	646.4
[H 4t(3-py)𝑃](Cl)2	451.0	647.5
Δν (cm^−1)	−1750.9	−26.2
H2t(4-py)P	416.0	643.0
[H 4t(4-py)𝑃](Cl)2	470.2	661.0
Δν (cm^−1)	−2770.9	−425.3

aSee Section  2.3 for details.