Synthesis, photophysical properties, and self-dimerization studies of 2-λ5-phosphaquinolin-2-ones

We have rationally designed and synthesized a library of phosphaquinolinone derivatives containing various electron-donating and -withdrawing groups on two positions of the scaffold. Distinct trends are observed between the substituents on R1 and R2 with both the photophysical properties of the molecules and their dimerization strengths. With withdrawing groups upon the scaffold, dimerization constants surpass 500 M−1 in H2O-saturated CDCl3. Computational studies on the dimeric structures corroborate the experimental findings.