Synthesis, photophysical properties, and self-dimerization studies of 2-5-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 R-1 and R-2 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.