In order to investigate the effect of C-F bonds on the π-electrons in PFCPPs, optical and electrochemical measurements as well as DFT calculations were carried out. The PFCPPs showed absorption in the UV region with absorption peaks at 270 nm for both PFCPPs (Fig. ), which is hypsochromically shifted compared to those of the corresponding CPPs ([10]CPP: 340 nm; [12]CPP: 338 nm) . While no obvious fluorescence was detected (F < 0.01) at room temperature, bright phosphorescence was observed at low temperature (≤ 150 K). As shown in Fig. , as dispersed solids in PMMA (poly(methyl methacrylate)), these PFCPPs exhibited phosphorescence with peak tops at 437 nm (PF[10]CPP) and 509 nm (PF [12]CPP) with long lifetimes (τ) of 2.0 s and 0.6 s, respectively. The phosphorescence quantum yields (F) in ethanol at 77 K were 0.21 (PF[10]CPP) and 0.62 (PF [12]CPP) (for details, see the SI). These photoluminescence properties clearly indicate that intersystem crossing occurs much more quickly compared to [10]-and [12]CPPs, which exhibit high fluorescence quantum yields at room temperature ([10]CPP: 0.46-0.65; [12]CPP: 0.66-0.89), presumably owing to the large dihedral angles of the PFCPPs (Fig. ) .