Two novel blue phosphorescent host materials containing phenothiazine-5,5-dioxide structure derivatives

Abstract

Two novel D–A bipolar blue phosphorescent host materials based on phenothiazine-5,5-dioxide: 3-(9H-carbazol-9-yl)-10-ethyl-10H-phenothiazine-5,5-dioxide (CEPDO) and 10-butyl-3-(9H-carbazol-9-yl)-10H-phenothiazine-5,5-dioxide (CBPDO) were synthesized and characterized. The photophysical, electrochemical and thermal properties were systematically investigated. CEPDO and CBPDO not only have a high triplet energy but also show a bipolar behavior. Moreover, their fluorescence emission peaks are in the blue fluorescence region at 408 nm and the fluorescence quantum efficiency (Φ) of CEPDO and CBPDO were 62.5% and 59.7%, respectively. Both CEPDO and CBPDO showed very high thermal stability with decomposition temperatures (T d) of 409 and 396 °C as well as suitable HOMO and LUMO energy levels. This preferable performance suggests that CEPDO and CBPDO are alternative bipolar host materials for the PhOLEDs.

Crystallization induced room-temperature phosphorescence and chiral photoluminescence properties of phosphoramides

“…On the other hand, incorporating main-group elements such as B, Si, N, P, O, S, and halogens in organic backbones provides a new strategy to achieve functional molecules. 35,48–76 Recently, finetuning the interactions between orbitals of different symmetry in heteroatom doped organic luminophores has attracted considerable attention for developing RTP materials. Not long ago, Huang and co-workers developed strongly emissive RTP materials by finetuning the interactions between sulfur and oxygen in oxidized phenothiazine derivatives.…”

Recent Advances in Monocomponent Visible Light Photoinitiating Systems Based on Sulfonium Salts

“…Indeed, phenothiazine is a polyaromatic structure absorbing in the visible range, even without substituents, so that various Type I and Type II photoinitiators were designed and synthesized with this structure [191][192][193][194][195][196][197]. This is also an excellent electron donor that was extensively used for the design of push-pull dyes developed for different applications in organic electronics such as energy conversion [198][199][200][201][202][203][204][205][206][207][208][209][210], light-emitting materials for organic light-emitting diodes (OLEDs) [211][212][213][214][215][216][217][218][219][220][221][222][223] or semi-conductors for organic field effect transistors (OFETs) [199,[224][225][226][227][228][229]. Phenothiazines were also developed as fluorescent probes for the detection of various molecules and ions in organic and aqueous solutions, food, live cells and animals [230][231][232]…”

Recent advances in materials for organic light emitting diodes

“…In addition, Lin Gan et al describe a new molecular design approach for orange-emitting TADF molecules employing a fluorenone acceptor [ 5 ]. In the full research paper by Feng-Ming Xie et al, they disclose two bipolar, high-energy phenothiazine-5,5-dioxide-based host materials conceived to be used for deep blue OLED devices [ 6 ].…”