Photomechanochemical control over stereoselectivity in the [2 + 2] photodimerization of acenaphthylene.

ABSTRACT: Tuning solubility and mechanical activation alters the stereoselectivity of the [2 + 2] photochemical cycloaddition of acenaphthylene. Photomechanochemical conditions produce the syn cyclobutane, whereas the solid-state reaction in the absence of mechanical activation provides the anti. When the photochemical dimerization occurs in a solubilizing organic solvent, there is no selectivity. Dimerization in H₂O, in which acenaphthylene is insoluble, provides the anti product. DFT calculations reveal that insoluble and solid-state reactions proceed via a covalently bonded excimer, which drives anti selectivity. Alternatively, the noncovalently bound syn conformer is more mechanosusceptible than the anti, meaning it experiences greater

SUBMITTER: Biswas S 

PROVIDER: S-EPMC10088556 | biostudies-literature | 2023 Jan

REPOSITORIES: biostudies-literature