Electronic and geometrical structures of cyclopropanes, part 51. fluorocyclopropanes. linear correlation of orbital energies with C–C bond lengths. further improvement of the two-orbitals model

Abstract

The electronic and geometrical structures of fluorocyclopropanes (1-12) have been analysed using DFT B3LYP calculations. A linear relationship, ε ω = − 0.172 r − 0.171 (n = 12, R = 0.931), between ε ω (in eV), the difference of the energies of the Walsh orbitals ω S and ω A , and r (in pm), the difference of vicinal and distal C-C bond lengths, is established. Correcting the orbital splitting by the basic value at r = 0.00 pm, an even better linear correlation ε ω eff = 0.0720 r (n = 12, R = 0.984) is obtained. The results confirm the general applicability of the two-orbitals model for the relationship between geometrical and electronic structures for substituted cyclopropanes.

Geometry and conformation of cyclopropane derivatives having σ-acceptor and σ-donor substituents: a theoretical and crystal structure database study

“…CSD results Perretta & Laurie (1975). (Rademacher, 2006) levels of theory provide geometrical data (Table 1b) which is in close agreement with our current DFT analysis in Table 1(a).…”

“…No C-C-F angles are given in either study. A recent DFT study (Rademacher, 2006) of CpF 3 has all the C-C ring bonds at 1.513 Å , while in CpF 6 they are all 1.527 Å . Whilst no C-C-F valence angles are given in the DFT study, the overall lengthening of the C-C bonds in the hexafluoro compound mirrors similar lengthenings in the corresponding hexachloro and hexabromo compounds for the reasons already discussed.…”

Visible‐Light‐Mediated Ring‐Opening Reactions of Cyclopropanes

“…The chlorine radical I initiate the oxidative ring opening of aryl cyclopropane 122, which is then reacted with molecular oxygen to form β-chloro ketones 123. It was evident from the 18 O labeling experiments that the ketone oxygen atom comes from molecular oxygen and not from a nucleophilic attack by water molecule.…”

“…The catalytic cycle was proposed on the basis of 18 O labeling experiment, UV/Vis measurements, cyclovoltammetry, and other Scheme 73. Mechanism for the photooxygenation of aryl cyclopropanes using ruthenium catalyst.…”

“…Cyclopropanes are unique moieties that grabbed the attention of synthetic chemists, [1][2][3][4][5][6][7][8][9] biochemists [10][11][12][13][14] as well as theoretical chemists. [15][16][17][18][19][20][21][22] Several methods are available for the synthesis of cyclopropanes and cyclopropenes, including photoredox methods. [23][24][25][26][27][28] Availability of these viable methods drew the attention of chemists to explore their reactivities.…”