In conclusion, four new phosphetene-substituted PAHs (either linear (5-6) or extended planar (7-8) were prepared and these compounds demonstrate intense emission in solution characteristic of PAH derivatives. As mentioned previously, the P-atom in these systems is stereogenic. To investigate the effect of the chirality on the optical properties, enantiopure samples (with ee > 99,5%) of linearly fused derivatives 5-6 were obtained via HPLC using a chiral stationary phase (see ESI). The absolute configuration of (R)-5 and (R)-6 was assigned using their X-ray diffraction structure (Fig. and). Electronic circular dichroism (ECD) was recorded in diluted DCM solutions. (R)-5 and (S)-5 (respectively (R)-6 and (S)-6) displayed ECD with the expected mirror-image relationship (Fig. ). For example, (R)-6 shows various positive ECD bands (e = +15 at 258 nm, e = +19 at 298 nm), negative bands (e = -16 at 290 nm, De = -16 at 338 nm and e = -7 at 380 nm). Interestingly, 5 and 6 present quite remarkable CPL (Fig. ) with glum ~ 9 10 -4 at 370 nm for 5 and glum ~ 1.1 10 -3 at 408 nm for 6, in agreement with their gabs values (for example, gabs(5) =2.10 -3 at 345 nm, and gabs(6) =9.9 10 -3 at 340 nm and =1.5 10 -3 at 380 nm). These values are typical for organic CPL emitters 2 but are rather unexpected as the P-atom has a very weak impact on the electronic properties (vide supra). This clearly shows that the chiral perturbation induced by the presence of the stereogenic Patom triggers the CPL activity of linear PAHs. In conclusion, four new polyaromatic fluorophores fused to a phosphetene ring 5-8 have been synthesized. These compounds exhibit the typical optical properties of polyaromatic compounds, such as structured absorption, and fluorescence with very low Stokes shift. The presence of the P atom (phosphine oxide) generates quasi-reversible electrochemical properties as well as chirality. The enantiopure samples 5-6 showed significant CPL emission induced by the chiral perturbation of the stereogenic P-center. Although the flanking four membered rings are not extensively involved in the HOMO and LUMO (or any other near-lying orbitals), their chiral characters induce asymmetry in the relevant orbitals, resulting in chiroptical properties. This observation opens many perspectives in the field of organic materials with chiroptical properties, given the diversity of chiral phosphines and P-rings.