A semiclassical molecular dynamics of the photochromic ring-opening reaction of spiropyran

The photochromic ring-opening reaction of spiropyran (SP) has been investigated by a realistic semiclassical dynamics simulation, accompanied by SA3-CASSCF(12,10)/MS-CASPT2 potential energy curves (PECs) of S0–S2. The main simulation results show the dominate pathway corresponds to the ring-opening process of trans-SP to form the most stable merocyanine (MC) product. These findings provide more important complementarity for interpreting experimental observations.

Graphical abstractA realistic semiclassical dynamics simulation shows the ring-opening reaction process from the excited spiropyran (SP) to the trans–cis–cis merocyanine (MC-TCC) then to MC-CCC, and finally to the stable MC-TTC product.Figure optionsDownload full-size imageDownload as PowerPoint slide