Intrinsic persistent room temperature phosphorescence derived from 1H-benzo[f]indole itself as a guest

The influence of 1H-benzo[f]indole(Bd) and its derivatives on room temperature phosphorescence(RTP)has raised great concern since they were found to significantly affect RTP of the extensively studied carbazole(Cz) derivatives. However, the role of Bd itself existing in Cz-based or other doping systems was still unclear. In order to clarify its intrinsic phosphorescent property, Bd was introduced as a guest into different organic matrixes including substituted Cz derivatives and polymers. The phosphorescence located in 560–620 nm was confirmed to be derived from Bd itself, which can be detected whatever Bd was doped in the crystal or amorphous state of Cz derivatives. The suitable energy gap between Cz derivatives and Bd is the key to achieve ultralong RTP of Bd. Additionally, when doped in polymers with plenty of hydrogen bonds, RTP of Bd with lifetime over 280 ms was easily obtained. Among them, Bd@PHEMA(poly(hydroxyethyl methacrylate) exhibited superior phosphorescence, with yellow afterglow lasting for over 2.5 s. Therefore, this work demonstrated that a new organic RTP phosphor, Bd, is discovered, and ultralong RTP of Bd can be achieved not only doped in Cz derivatives but also in polymers as the hosts.

Environmental control of rice flowering time

Correct measurement of environmental parameters is fundamental for plant fitness and survival,as well as for timing developmental transitions,including the switch from vegetative to reproductive growth.Important parameters that affect flowering time include day length(photoperiod)and temperature.Their response pathways have been best described in Arabidopsis,which currently offers a detailed conceptual framework and serves as a comparison for other species.Rice,the focus of this review,also possesses a photoperiodic flowering pathway,but 150 million years of divergent evolution in very different environments have diversified its molecular architecture.The ambient temperature perception pathway is strongly intertwined with the photoperiod pathway and essentially converges on the same genes to modify flowering time.When observing network topologies,it is evident that the rice flowering network is centered on EARLY HEADING DATE 1,a rice-specific transcriptional regulator.Here,we summarize the most important features of the rice photoperiodic flowering network,with an emphasis on its uniqueness,and discuss its connections with hormonal,temperature perception,and stress pathways.