Diphenyl cyclopropenone-centered polymers for site-specific CO-releasing and chain dissociation

The synthesis and stimuli-responsiveness of a diphenyl cyclopropenone (DPCP)-centered poly(methyl acrylate) (PMA) are presented. DPCP-centered PMA could release carbon monoxide (CO) upon UV light in a switched on-and-off manner. The CO-releasing process can be reported by the variations in photoluminescence spectra. In addition, DPCP moiety covalently embedded in the crosslinked polyurethane could also release CO under UV light. Of special, DPCP-centered PMA in solution was selectively dissociated at the phenol ester bond under the ultrasound, and a force-induced hydrolyzation reaction was revealed by D₂O exchanging ¹H NMR spectra. The kinetic study reveals that small quantity of water could enhance the chain scission rate. This work provides a DPCP-centered polymer for sitespecific CO-releasing and chain dissociation.