Synthesis and optical properties of phenazinone-based photosensitizers for singlet oxygen generation

Abstract

Phenazinone derivatives PZ1–3 where a carbonyl group is incorporated in the chromophore are designed and developed as halogen-atom-free-heteroanthracene-based photosensitizers possessing the ability to generate singlet oxygen (1O2). Compared to the...

Photochromism of phenazine-2,3-diol derivatives through excited state intermolecular proton transfer based on keto–enol tautomerization

“…aFluorescence quantum yields ( λ ex = 390 nm and 480 nm for PD1 , 385 nm for PD2 , 385 nm for PD3 , 378 nm for PZ1 , and 361 nm for PZ2 ) were determined using a calibrated integrating sphere system.bFluorescence lifetimes.cPhotoexcited at 366 nm.dPhotoexcited at 451 nm.eIn our previous study. 17 …”

“…One would make the assumption that the ESInterPT process requires the presence of intermolecular hydrogen bonding between proton donors and acceptors. Thus, to investigate the formation of the hydrogen bonding for PD1 and PD2 in the aggregate state, single-crystal X-ray structural analyses for PD1 and PD2 were performed, in comparison with those for PZ1 and PZ2 in our previous study 17 (Fig. 9 and 10).…”

“…5). 17,18 Indeed, as evidence of the formation of phenoxide ions, for PD1, an increase in the absorbance at around 480 nm was observed with increasing water content in the THF solution (Fig. 4a); meanwhile, when water was added to the THF solution of PD2, a photoabsorption band appeared at 480 nm and the absorbance increased with the increase in water content (Fig.…”

“…In our previous study, 17 we designed and developed phenazinone derivatives PZ1 and PZ2 having a similar structure to the keto form of phenazine-2,3-diol PD1 and its monoalkoxy derivative PD2 , respectively (Fig. 1 and 2).…”

Structure‐Activity Relationship of Benzophenazine Derivatives for Homogeneous and Heterogenized Photooxygenation Catalysis

“…Previous investigations have focused on (benzo)phenazines in homogeneous phase to determine the best candidate for 1 O 2 generation. Ohira, Imato and coworkers developed several phenazine derivatives to increase their 1 O 2 generation efficiency [18b,c,e] . Surprisingly, such simple photosensitizers have not yet been investigated for 1 O 2 generation for organic synthesis applications.…”