The “Bond‐Stretched Invertomer” of Hexafluorocyclopropane—a New Type of Reactive Intermediate

Chain elongation during thermolysis of tetrafluoroethylene and hexafluoropropylene: Modeling of mechanistic hypotheses and elucidation of data needs

“…The 1,3-biradical: Recent computations by Wei and coworkers [71] support earlier suggestions [94,96] that step (7), contrary to the general behavior of singlet carbenes, is not concerted but proceeds through a specially stabilized singlet 1,3-biradical intermediate which was described as a C 2v "bond-stretched invertomer" of c-C 3 F 6…”

“…Of the eight required A and E parameters, only two have a literature source, i.e., the barriers E 9 = 9.8 and E −9 = 30.5 kcal/mol from the computations of Wei and coworkers [71]. Noting Fig.…”

“…The hypothetical symmetrical TS5 for concerted cycloaddition is placed based on computations by Bilera and coworkers [60]. However, there is ambiguity in that the alternate computations [71] place it some 20 kcal/mol lower, i.e., only slightly above our placement of TS4. Much the same two-step mechanism with a distinct energy minimum for the 1,3-biradical was developed earlier by Bilera and coworkers [60] from computations and literature and experimental data.…”

“…11. The levels for CF 2 :, CF 2 CF 2 , and c-C 3 F 6 are "experimental" values from Table 1; the computations of Wei and coworkers [71] were used to place the 1,3-biradical (see above) and TS3 ( ‡ H −9 = 30.5 kcal/mol). Since the level of TS3 lies below that of (CF 2 : + C 2 F 4 ), we assume that the rate-controlling transition state for overall step (7) (see below) is the unsymmetrical TS4; it is placed based on our dissection of k 7 described below.…”

CF : A first-principles study of structural patterns arising during synthetic growth

“…In contrast to recent works dedicated to computer simulations of fluorination of relatively small organic molecules [19,20,21], in our calculations we employ considerably larger graphene-like model systems based on coronene and corannulene-molecules. The nomenclature of four typical structural CF x patterns discussed here corroborates the understanding of the growth mechanism of magnetron sputtered CF x films and provides suggestions how to control the CF x films' structure.…”