Matches in SemOpenAlex for { <https://semopenalex.org/work/W2103176800> ?p ?o ?g. }
- W2103176800 endingPage "7744" @default.
- W2103176800 startingPage "7731" @default.
- W2103176800 abstract "Branched alkanes like isobutane and neopentane are more stable than their straight chain isomers, n-butane and n-pentane (by 2 and 5 kcal mol−1, respectively). Electron correlation is largely responsible. Branched alkanes have a greater number of net attractive 1,3-alkyl–alkyl group interactions, there are three such stabilizing 1,3 “protobranching” dispositions in isobutane, but only two in n-butane. Neopentane has six protobranches but n-pentane only three. Propane has one protobranch and is stabilized appreciably, by 2.8 kcal mol−1, relative to methane and ethane. This value per protobranch also applies to the n-alkanes and cyclohexane. Consequently, energy evaluations employing alkane reference standards, for example, of small ring strain and stabilizations due to conjugation, hyperconjugation, and aromaticity, should be corrected for protobranching, for example, by employing Pople's isodesmic bond separation reaction method. This reduces the ring strain of cyclopropane to 19.2 from the conventional 27.7 kcal mol−1, while the stabilization energies of alkenes and alkynes due to hyperconjugation (5.5 and 7.7 kcal mol−1 for propene and propyne) and conjugation (14.8 and 27.1 kcal mol−1 for butadiene and butadiyne) are considerably larger than the traditional estimates. Widely diverging literature evaluations of benzene resonance energy all give ≈65 kcal mol−1 after adjusting for conjugation, hyperconjugation, and protobranching “contaminations.” The BLW (block localized wavefunction) method, which localizes π bonds and precludes their interactions, largely confirms these stabilization estimates for hyperconjugation, conjugation, and aromaticity. Protobranching is seriously underestimated by theoretical computations at the HF and most DFT levels, which do not account for electron correlation satisfactorily. Such levels give bond separation energies, which can differ greatly from experimental values." @default.
- W2103176800 created "2016-06-24" @default.
- W2103176800 creator A5011717029 @default.
- W2103176800 creator A5011835456 @default.
- W2103176800 creator A5042178740 @default.
- W2103176800 creator A5049309461 @default.
- W2103176800 creator A5052766830 @default.
- W2103176800 creator A5076317766 @default.
- W2103176800 date "2007-09-17" @default.
- W2103176800 modified "2023-10-16" @default.
- W2103176800 title "The Concept of Protobranching and Its Many Paradigm Shifting Implications for Energy Evaluations" @default.
- W2103176800 cites W1574356778 @default.
- W2103176800 cites W1971803965 @default.
- W2103176800 cites W1973403327 @default.
- W2103176800 cites W1973446427 @default.
- W2103176800 cites W1975160218 @default.
- W2103176800 cites W1975708211 @default.
- W2103176800 cites W1978162420 @default.
- W2103176800 cites W1978396634 @default.
- W2103176800 cites W1979939908 @default.
- W2103176800 cites W1981291305 @default.
- W2103176800 cites W1981828560 @default.
- W2103176800 cites W1982044891 @default.
- W2103176800 cites W1983103022 @default.
- W2103176800 cites W1983535181 @default.
- W2103176800 cites W1986518757 @default.
- W2103176800 cites W1987796086 @default.
- W2103176800 cites W1993180382 @default.
- W2103176800 cites W1993999000 @default.
- W2103176800 cites W1996541391 @default.
- W2103176800 cites W1997303632 @default.
- W2103176800 cites W2000937707 @default.
- W2103176800 cites W2003512449 @default.
- W2103176800 cites W2003691545 @default.
- W2103176800 cites W2004728230 @default.
- W2103176800 cites W2013032231 @default.
- W2103176800 cites W2013236757 @default.
- W2103176800 cites W2015086168 @default.
- W2103176800 cites W2015358981 @default.
- W2103176800 cites W2015459255 @default.
- W2103176800 cites W2020753183 @default.
- W2103176800 cites W2025759763 @default.
- W2103176800 cites W2036836472 @default.
- W2103176800 cites W2038936521 @default.
- W2103176800 cites W2042441465 @default.
- W2103176800 cites W2042796027 @default.
- W2103176800 cites W2044163988 @default.
- W2103176800 cites W2044591029 @default.
- W2103176800 cites W2049976780 @default.
- W2103176800 cites W2050537696 @default.
- W2103176800 cites W2052080248 @default.
- W2103176800 cites W2052099987 @default.
- W2103176800 cites W2052663864 @default.
- W2103176800 cites W2054725129 @default.
- W2103176800 cites W2056345462 @default.
- W2103176800 cites W2059121232 @default.
- W2103176800 cites W2060491737 @default.
- W2103176800 cites W2063272142 @default.
- W2103176800 cites W2063589866 @default.
- W2103176800 cites W2066584524 @default.
- W2103176800 cites W2068975370 @default.
- W2103176800 cites W2070203126 @default.
- W2103176800 cites W2071088618 @default.
- W2103176800 cites W2072754743 @default.
- W2103176800 cites W2075381847 @default.
- W2103176800 cites W2075386661 @default.
- W2103176800 cites W2076937419 @default.
- W2103176800 cites W2079256799 @default.
- W2103176800 cites W2081939952 @default.
- W2103176800 cites W2083829149 @default.
- W2103176800 cites W2086957099 @default.
- W2103176800 cites W2088779490 @default.
- W2103176800 cites W2089750480 @default.
- W2103176800 cites W2090970177 @default.
- W2103176800 cites W2093432634 @default.
- W2103176800 cites W2096043120 @default.
- W2103176800 cites W2098985212 @default.
- W2103176800 cites W2104861651 @default.
- W2103176800 cites W2105512706 @default.
- W2103176800 cites W2106298831 @default.
- W2103176800 cites W2109129868 @default.
- W2103176800 cites W2112054650 @default.
- W2103176800 cites W2114030802 @default.
- W2103176800 cites W2116502442 @default.
- W2103176800 cites W2120787330 @default.
- W2103176800 cites W2134670420 @default.
- W2103176800 cites W2149533343 @default.
- W2103176800 cites W2157915887 @default.
- W2103176800 cites W2163274886 @default.
- W2103176800 cites W2164827516 @default.
- W2103176800 cites W2171445884 @default.
- W2103176800 cites W2313513535 @default.
- W2103176800 cites W2316326193 @default.
- W2103176800 cites W2317452699 @default.
- W2103176800 cites W2321781324 @default.
- W2103176800 cites W2324653063 @default.
- W2103176800 cites W2329016261 @default.
- W2103176800 cites W2331983058 @default.