Experimental and theoretical studies of benzoquinone modified poly(ortho-phenylenediamine): singlet oxygen generating oligomers

Abstract

The present work reports microwave-assisted polymerization of 1,4-benzoquinone with ortho-phenylenediamine for the effective generation of singlet oxygen ( 1 O 2 ). The oligomeric structures were confirmed by the experimental IR, 1 H-NMR, ultravioletvisible and TEM analyses. The theoretical IR and UV data were computed using DFT/B3LYP method with 6-311G basis set, and the 1 H-NMR spectra were computed by gauge-independent atomic orbital (GIAO) method. The experimental IR, 1 H-NMR, and UV studies were found to be in close agreement with the experimental investigations. The TEM studies confirmed the formation of mixed morphology consisting of cluster of fused particles joined together to form entangled chains. 1 O 2 generation studies revealed that the oligomer containing 70% benzoquinone content exhibited the highest quantum yield value of 0.057. These results hold promise for utilization of these oligomers as photosensitive probes applicable in photodynamic therapy for the treatment of various infectious diseases.

A comprehensive review on singlet oxygen generation in nanomaterials and conjugated polymers for photodynamic therapy in the treatment of cancer

“…They proposed that their findings could be useful in the application of engineered oligomers as photosensitive probes for photodynamic treatment. 155 Singh et al also reported novel azo benzene functionalized aniline, 1-naphthylamine, luminol and o -phenylenediamine prepared by using an ultrasound technique. The researchers suggested that the synthesized polymers also showed high singlet oxygen generation characteristics.…”

Theoretical studies of conducting polymers: a mini review

“…Lately, Riaz et al 78 have reported the theoretical IR and UV data of 1,4-benzoquinone with ortho -phenylenediamine using the DFT/B3LYP method with the 6-311G basis set, and the 1 H-NMR spectra were computed by the gauge-independent atomic orbital (GIAO) method (Fig. 12).…”

A comparison of experimental and theoretical studies of benzoquinone modified poly(thiophene): effect of polymerization techniques on the structure and properties

“…Optimizations of PTh/BQ geometries were carried out without symmetry constraints by using hybrid functional DFT/B3LYP method with 6-311G basis set. [13][14][15] The geometric optimization was carried out by taking 3 units of thiophene, coupled with 3 units of benzoquinone/ hydroquinone. The frequency calculations (IR spectra) were computed by using same method, while the electronic transitions were calculated by using the time-dependent DFT (TD-DFT) method with 6-311G basis set.…”

“…The quantum yields (F) were calculated as per the reported method by using Rhodamine B as a reference. [13][14][15] .…”