Aggregation effect of Thiazine dyes over Singlet Oxygen quantum yield

VARA, JIMENA; ORTIZ CRISTINA

INTERNATIONAL JOURNAL OF PHARMACEUTICAL SCIENCES AND RESEARCH

Institute of Pharmacy, Bundelkhand University Jhansi (U.P.), India

Año: 2014

hiazine dyes are used for coloring substrates in biological and medical studies and are promising compounds for photosensitizing applications. Recent identification, in our laboratory, of the monomeric species of these dyes showed that the monomer described in literature corresponds to different dimers. Due to the aggregation of photosensitizers reduces the production of singlet oxygen (1O2), the objective of this study was to evaluate the 1O2 quantum yield (ΦΔ) of the monomeric and dimeric species of two Thiazines: Azure B (AzB) and monobrominated Azure B (AzBBr). Phosphorescence decay of 1O2 and photooxidation of 9,10-dimethylanthracene (DMA) were used as methodology. Monomeric and dimeric forms were analyzed in N,N-dimethylformamide (DMF) and Methanol (MeOH) employing Rose Bengal (RB) and Methylene Blue (MB) as references. Monomeric species of AzBBr and AzB presented high Φ by luminescence (1.0 and 0.72, respectively) and low values by photooxidation of DMA (