作者:Evi Honegger、Edgar Heilbronner、Thomas Urbanek、Hans-Dieter Martin
DOI:10.1002/hlca.19850680104
日期:1985.2.13
therefore, hyperconjugate appreciably with both sets. Interaction with the lower-lying set will lead to the usual destabilization (‘normal’ hyperconjugation), whereas interaction with the set above will necessarily lead to a ‘stabilization’ (‘inverted’ hyperconjugation). As a result the lone-pair ionization energies of Cl or Br substituted cubanes (derived from PE spectra) are much larger than naively expected
如其PE光谱所暗示的,古巴1的σ轨道流形被分成两组,由3 eV的间隙隔开,该间隙从-10.5 eV到-13.5 eV。np AO基能落入该间隙的卤素取代基(例如因此,C 1或Br 2将与两组显着超共轭。与低层组的相互作用将导致通常的不稳定(“正常”过度共轭),而与上述组的相互作用将必然导致“稳定”(“反向”过度共轭)。结果,Cl或Br取代的古巴人的孤对电离能(源自PE光谱)比天真预期的含多达8个C原子的烷基卤化物的电离能大。特别是,相对于自由原子Cl和Br或HCl的第一电离能,没有检测到1,4-二氯-和1,4-二溴代古巴的PE光谱中的孤对带有明显变化。和HBr。