Epoxy density functional theory

Irradiation of 2,5-dimethylbenzoyl oxiranes results in formation of p-hydroxy functionalized indanones (74) that structurally resemble biologically active pterosines. Nanosecond laser flash photolysis and quantum-chemical calculations based on density functional theory support a photoenolization mechanism.Reversible photochemical transformations of cis- and tra v-2,3-dimethyloxirane radical cations in freonic matrices at 77 K has been observed and explained by the interconversion between the open (C2-C3 broken) and the cyclic forms. Photocatalytic ring opening of a-epoxy ketones in cyclopentanone, using 2,4,6-triphenylpyrylium tetra-fluoroborate as electron acceptor, results in the diastereoselective formation of 2,5-dioxaspiro[4,4]nonanes through Ca-O bond cleavage and subsequent nucleophilic attack by cyclopentanone to the radical cation intermediates. ... 

It should be noted that, for all the resins considered, the specific heat does not depend on cross-linking or the chemical structure below 100 K. This can be explained by the Debye theory, which states that the specific heat is a function only of the oscillator density, N, and 0/T. 6 is the Debye temperature, which can be determined by elastic parameters, such as Young s modulus, E, N is approximately equal for all resins, since they have nearly equal densities. At low temperatures, roughly the same value of E is asymptotically reached by the epoxy resins. 

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