title: Pressure dependence of the forward and backward rates of 9-tert-butylanthracene Dewar isomerization.
abstract: 9-tert-Butylanthracene undergoes a photochemical reaction to form its strained Dewar isomer, which thermally back-reacts to reform the original molecule. When 9-tert-butylanthracene is dissolved in a polymer host, we find that both the forward and reverse isomerization rates are pressure-dependent. The forward photoreaction rate, which reflects the sum of contributions from photoperoxidation and Dewar isomerization, decreases by a factor of 1000 at high pressure (1.5 GPa). The back-reaction rate, on the other hand, increases by a factor of ∼3 at high pressure. Despite being highly strained and higher volume, the back-reaction reaction rate of the Dewar isomer is at least 100× less sensitive to pressure than that of the bi(anthracene-9,10-dimethylene) photodimer studied previously by our group. These results suggest that the high pressure sensitivity of the bi(anthracene-9,10-dimethylene) photodimer reaction is not just due to the presence of strained four-membered rings but instead relies on the unique molecular geometry of this molecule.
authors: Department of Chemistry, University of California Riverside , 501 Big Springs Road, Riverside, California 92521, United States.
authors: Fei
authors: F
authors: Tong
authors: Chad D
authors: CD
authors: Cruz
authors: Sebastian R
authors: SR
authors: Jezowski
authors: Xiaoquan
authors: X
authors: Zhou
authors: Lingyan
authors: L
authors: Zhu
authors: Rabih O
authors: RO
authors: Al-Kaysi
authors: Eric L
authors: EL
authors: Chronister
authors: Christopher J
authors: CJ
authors: Bardeen
mesh_terms: D000873:Anthracenes / Q000737:chemistry*; D007536:Isomerism; D007700:Kinetics; D015394:Molecular Structure; D055668:Photochemical Processes; D011312:Pressure; D013057:Spectrum Analysis
chemical_list: D000873:Anthracenes