English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Equilibrium acidities in DMSO are reported for nine cycloalkanones, acetone, acetophenone, and 19 of their α-substituted derivatives. Oxidation potentials in DMSO for the conjugate bases of most of these ketones are also reported. Combination of these E OX (A − ) and pK HA  values gives estimates of the homolytic bond dissociation energies (BDEs) of the acidic C—H bonds in the ketones. The ΔBDEs, relative to the BDE of CH 3 -H, or a parent ketone, provide a measure of the radical stabilization energies (RSEs) of the corresponding radicals. The effects of successive α-Me and α-Ph substitutions on RSEs, relative to those of CH 3 COCH 2 -H or PhCOCH 2 -H, are similar to those reported in the gas phase for methane. The RSE for the MeĊHCOPh radical, relative to CH 3 • is 17 kcal/mol, which is smaller than the sum of the RSEs of the MeCH 2 • and PhCOCH 2 • radicals relative to CH 3 • (7 + 12 = 19), contrary to the prediction of the captodative postulate. When G in PhCOCH 2 G is PhCO, CH 3 CO, or CN the ΔBDEs (relative to PhCOCH 2 -H) are 0, 1, and 3 respectively; for MeCOCH 2 SO 2 Ph, PhCOCH 2 SO 2 Ph, and PhCOCH 2 NMe 3  +  the ΔBDEs are −5, −2, and −4, respectively. The BDEs in C 5 , C 6 , C 7 , C 8 , C 10 , and C 12  cycloalkanones are within ±2.5 kcal/mol of that of 3-pentanone. Acetophenones bearing meta or para substituents all have BDEs of 93-94 kcal/mol. Ketone radical cations, [RCOR′] +• , appear to be superacids with estimated [Formula: see text] values below −25. Keywords: acidities, bond dissociation energies, ketones.

Acidities and homolytic bond dissociation energies of the αC—H bonds in ketones in DMSO