Introduction of carboxylic ester and acid functionalities to meso-tetrakis(pentafluorophenyl)porphyrin and their limited electronic effects on the chromophore

Abstract

Please cite this article as: Hewage N, Yang B, Agrios AG, Brückner C, Introduction of Carboxylic Ester and Acid Functionalities to meso-Tetrakis(pentafluorophenyl)porphyrin and their Limited Electronic Effects on the Chromophore, Dyes and Pigments (2015), AbstractAlkyl-or aryl-carboxylic acid-functionalized porphyrinic dyes are sought after because of their propensity to adhere strongly to many metal oxide surfaces as required for their application as, for instance, sensitizers in dye-sensitized solar cells (DSSCs), in air purification, or chemosensing systems. The S N Ar reaction of the pentafluorophenyl group is a versatile method to introduce functionality into meso-pentafluorophenyl-substituted porphyrins. The conditions to introduce one through four alkyl-or aryl-carboxyl functionalities using mercaptopropionate or 3,4-dihydroxybenzoate esters, respectively, are explored, and the regioisomeric products are spectroscopically characterized. Their saponification to the corresponding carboxylic acids was studied. By experimental determination of their optical properties (absorption and emission spectroscopy) and their frontier orbital positions by cyclic voltammetry, we demonstrate the minimal electronic influence this derivatization method has on the chromophore.

Sequential Nucleophilic Substitution of the α‐Pyrrole and p‐Aryl Positions of meso‐Pentafluorophenyl‐Substituted BODIPYs

“…Figure shows the normalized absorption spectra of BODIPYs 1c / e , 3e / g , 7a / d , 8a , and 9a . As expected, substitution of the p ‐position of the meso ‐aryl group has no pronounced effect on the absorption spectra , . Substitution at this position can primarily be used to change the hydrophilic/hydrophobic properties of the BODIPY .…”

Nucleophilic Aromatic Substitution on Pentafluorophenyl‐Substituted Dipyrranes and Tetrapyrroles as a Route to Multifunctionalized Chromophores for Potential Application in Photodynamic Therapy

“…Within one class of chromophores (porphyrins, corroles, and BODIPYs), the different substituents did not give rise to significant changes in the absorption properties; that is, the exchange of the para ‐fluorine substituent by alkoxy or amino moieties had only a very limited effect on the chromophore. This limited effect has also been observed for porphyrins in which more than one fluorine atom in the PFP‐moieties has been exchanged . It can mainly be attributed to the tilt angle of the substituted phenyl ring relative to the chromophore plane (e.g., see above, the X‐ray crystallographic data of the BODIPYs), which lowers the electronic interaction…”

“…This limited effect has also been observed for porphyrins where more than one fluorine atom in the PFP moieties has been exchanged. [48] It can mainly be attributed to the tilt angle of the substituted phenyl ring relative to the chromophore plane (cf. e.g.…”

Antimicrobial Photodynamic Polymeric Films Bearing Biscarbazol Triphenylamine End-Capped Dendrimeric Zn(II) Porphyrin

“…It can be note that Q(0-0) band is a smaller transition than Q(0-1), which is distinctive of pentafluorophenyl porphyrin derivatives. [45][46][47] Moreover, the energy levels values of the singlet excited state (E s ) were estimated for both photosensitizers (Table 1). E s values are comparable to those previously reported for zinc(II) porphyrins.…”