Photooxidation of 4-chlorophenol sensitised by iron meso-tetrakis(2,6-dichloro-3-sulfophenyl)porphyrin in aqueous solution

• Type: Article in International Scientific Journal
• Date: 2004

Authors

Silva, E (Author) Other; Pereira, MM (Author) Other; Burrows, HD (Author) Other; Azenha, ME (Author) Other; Sarakha, M (Author) Other; Bolte, M (Author) Other

Journal

Title: Photochemical & Photobiological Sciences

Vol. 3

Pages: 200-204

ISSN: 1474-905X

Publisher: Springer Nature

Indexing

ISI Web of Knowledge - 53 Citations

Scopus - 52 Citations

Other information

Authenticus ID: P-000-DCD

DOI: 10.1039/b308975d

Abstract (EN): The photosensitised degradation of 4-chlorophenol (4-CP) by iron meso-tetrakis( 2,6-dichloro-3-sulfophenyl)porphyrin ( FeTDCPPS) has been studied in aerated aqueous solution, and is shown to lead to formation of p-benzoquinone (BQ) and p-hydroquinone (HQ) as main photoproducts. In deaerated solution no p-benzoquinone was formed. The photolysis products were identified by high performance liquid chromatography ( HPLC) and UV-visible spectroscopy. The photodegradation in aerated solution was also carried out in the presence of sodium azide (NaN3) as a singlet oxygen [O-1(2)((1)Delta(g))] quencher, and showed a significant decrease in the rate of photolysis, suggesting under these conditions, that Type II sensitisation is one of the dominant mechanisms of 4-CP degradation. Support for this comes from laser. ash photolysis and time-resolved singlet oxygen phosphorescence measurements. However, these also show direct reaction between the excited porphyrin and 4-CP, indicating that there are two mechanisms involved in the chlorophenol photodegradation.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 5