Influence of the meso-substituents on the spectral features of free-base porphyrin

Supramolecular porphyrin as an improved photocatalyst for chloroform decomposition

“…2c) shows a small redshift (∼1 nm) regarding H 2 TPyP . This effect is accompanied by obtaining a 72% lower emission quantum yield for Supra-H 2 TPyP concerning H 2 TPyP 22 (see Table 1), in agreement with previous reports. 49–52 The Supra-H 2 TPyP also presents a variation in the relative intensity between electronic (Q(0,0)) and vibronic (Q(0,1)) emission bands with relation to H 2 TPyP , which indicates that either (1) the involved H 2 TPyP vibronic progressions are changing 52,53 or (2) a new band arises and overlaps with H 2 TPyP original bands.…”

“…4d shows that, at 7200 J cm −2 , the quenching of these lifetimes, τ 2(0) / τ 2 ( PP-Supra-H 2 TPyP ) and τ 3(0) / τ 3 (protonated PP-Supra-H 2 TPyP ), are 1.02 and 1.47, which originates from exciplex formation. 22 The quenching of the protonated PP-Supra-H 2 TPyP is 144% more effective in comparison with that for PP-Supra-H 2 TPyP . This result supports the presence of electrostatically-enhanced exciplex formed between the positively charged protonated PP-Supra-H 2 TPyP and Cl − ions dispersed in the solution.…”

“…The PL decays were collected at the maximum of each spectrum. Emission quantum yields 58,59 were calculated adopting H 2 TPyP dissolved in CHCl 3 as standard 22 and applying eqn (1):where, Φ sa and Φ st stand for the quantum yields of the sample (sa) and standard (st) solution, respectively. The quantities Abs st (F st ) and Abs sa ( F sa ) are the absorbances at 420 nm (the integrated PL spectrum for the corresponding excitation) from the sample and standard solutions.…”

“…The excited-state dynamics exhibited by porphyrins 21–25 set them as versatile molecular photocatalysts 15,26–29 that have been explored in fields like dye-sensitized solar cells, 30–33 photomedicine, 34–36 and artificial photosynthesis. 37–39 In the last decades, these macrocycle molecules have been explored as photocatalysts for dye-mediated decomposition of chloroform (CHCl 3 ) under one-photon absorption (OPA) and/or excited-state absorption (ESA).…”

“…Concerning the effort (2), although the biotechnological 12,13 and the pulsed-corona-dischargesassisted 14 approaches have been lately tested, the dye-catalyzed photochemical-based approaches stand as low-cost, noninvasive, selective, and controllable alternatives. [15][16][17][18][19][20] The excited-state dynamics exhibited by porphyrins [21][22][23][24][25] set them as versatile molecular photocatalysts 15,[26][27][28][29] that have been explored in elds like dye-sensitized solar cells, [30][31][32][33] photomedicine, [34][35][36] and articial photosynthesis. [37][38][39] In the last decades, these macrocycle molecules have been explored as photocatalysts for dye-mediated decomposition of chloroform (CHCl 3 ) under one-photon absorption (OPA) and/or excitedstate absorption (ESA).…”