A2B2 type porphyrins with meso-donor groups: Synthesis, X-ray structures, DFT studies and photocatalytic application using sunlight. (January 2023)

• Record Type: Journal Article
• Authors: Pandey, Vijayalakshmi; Janaagal, Anu; Jain, Ashmita; Mori, Shigeki; Gupta, Iti
• Is Part Of: Dyes and pigments. Volume 209(2023)Supplement Part A
• Publication Date: 2023-01
• Subjects: D-A porphyrins -- Energy transfer -- Singlet oxygen -- Photo-catalysis -- Pd(II) porphyrin -- Cyclic voltammetry; Dyes and dyeing -- Periodicals; Pigments -- Periodicals; 667.2
• DOI: 10.1016/j.dyepig.2022.110861
• Languages: English
• ISSNs: 0143-7208

Abstract

Abstract: The trans -A2 B2 type porphyrins bearing thiophene linked N -butylcarbazole or N -butylphenothiazine groups at the meso -positions were synthesized. Donor−acceptor (D−A) type meso- substituted porphyrins and their Zn(II) and Pd(II) complexes were studied by UV–vis absorption, fluorescence and electrochemical techniques. These porphyrins exhibited efficient energy transfer (∼78%) from the meso -donors (thiophene linked N -butylcarbazole or N -butylphenothiazine groups) to the porphyrin core. Also, the Soret band of porphyrins was noticeably broad, indicating significant communication between the meso -donor groups and the porphyrin core. The donor−acceptor interaction between the porphyrin core and the meso -donors was supported by X-ray analysis and DFT studies of these D-A systems. The photo-catalytic application of Pd(II) porphyrin was demonstrated by efficient singlet oxygen generation (68%) and effective oxidation of aromatic aldehydes to their corresponding carboxylic acids (up to 99%) in the presence of white light or sunlight. Graphical abstract: Image 1 Highlights: Donor-Acceptor (D-A) type trans -A2 B2 porphyrins and their Zn(II) and Pd(II) complexes are reported. The D groups are linked via thiophene ring to the porphyrin core (A); porphyrins showed efficient energy transfer (78%) from D to A. All the porphyrins were studied by UV–Vis absorption, fluorescence and cyclic voltammetry techniques. Donor-Acceptor interaction between the porphyrin core and meso -donors was supported by the X-ray crystal analysis and DFT studies. Pd(II) porphyrin was used as efficient catalyst for the photo-oxidation of aromatic aldehydes under white LED or sunlight.