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 6

UV-vis spectral data for protonation of H₂t(3-Mepy)P with different acids in methanol.

Porphyrins and the dications	Soret band	Q(0,0) band
	(λ/nm)	(λ/nm)
H2t(3-Mepy)P	419.3	639.7
[H4t(3-Mepy)P](CH3COO)2	437.4	632.8
Δν (cm^−1)^a	−987.0	168.0
[H4t(3-Mepy)P](Cl)2	433.1	639.6
Δν (cm^−1)	−1281.0	2.4
[H4t(3-Mepy)P](HSO4)2	436.3	632.8
Δν (cm^−1)	−929.0	168.0
[H4t(3-Mepy)P](CF3COO)2	433.5	631.5
Δν (cm^−1)	−781.0	201.0

aRelative to the bands of H₂t(3-Mepy)p.