The odd–even effect of alkyl chain in organic room temperature phosphorescence luminogens and the corresponding in vivo imaging

Abstract

The odd–even effect is utilized to rationally design organic luminogens with the room temperature phosphorescence (RTP) effect. By just simply modifying the different alkyl substituents, the phenothiazine 5,5-dioxide derivatives exhibit totally different RTP properties, with the best performance achieved by CS-C₃H₇ having a phosphorescence lifetime of up to 327 ms. Furthermore, excitation-free phosphorescence imaging in living mice has been successfully realized, opening up a new avenue to promote the RTP effect in purely organic luminogens as well as the corresponding application in bio-imaging.