Crystallines, acenaphthylene

Irradiation of crystalline acenaphthylene at temperatures below 25 C results in formation of the trow j-cyclobutane dimer only. At temperatures above 40°C both cis and trans dimers are formed, with the cis dimer predominating at 60 C (Table 10.12). The formation of the trans dimer, whidi occurs with low quantum yield at all temperatures studied, is thought to... 

Similar results have been observed in the photodimerization reaction of acenaphthylene [732, 733] cf. Eq. (5-161) in Section 5.5.8. A considerable increase in the production of the traro-adduct was reported in cholesteric liquid-crystalline media compared to the isotropic solvent benzene, in which the cu-adduct is the dominant product... 

Surprisingly, some Diels-Alder cycloaddition reactions show no variation in endojexo product ratio with changes in solvent phase. Ordered liquid-crystalline solvents are not able to differentiate between endo- and exo-activated complexes in the Diels-Alder reaction of 2,5-dimethyl-3,4-diphenylcyclopentadienone with dienophiles of varying size (cyclopentene, cycloheptene, indene, and acenaphthylene), when it is carried out in isotropic (benzene), cholesteric (cholesteryl propionate), and smectic liquid-crystalline solvents at 105 °C [734]. 

On exploring the reaction of osmium tetroxide with olefins in a nonaqueous solvent (ether, also benzene, cyclohexane), Criegee promptly confirmed the Boeseken hypothesis. From acenaphthylene, indene, A -ditralin, and A -octalin he obtained nicely crystalline, bright colored osmate esters in yields of 89-99% no... 

Dimerization of Acenaphthylene in the Crystalline or Solid State Dimerization on Sihca Gel Surfaces ... 

Haga, N., Nakajima, H., Takayanagi, H., and Tokumaru, K., Photoinduced electron transfer between acenaphthylene and tetracyanoethylene. Effect of irradiation mode on reactivity of the charge-transfer complex and the resulted radical ion pair in solution and crystalline state, /. Org. Chem., 63, 5372, 1998. 

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