Supersonic jet studies of alkyl-substituted pyrazines and pyridines. Minimum-energy conformations and torsional motion
作者:Jeffrey I. Seeman、John B. Paine、Henry V. Secor、Hoong Sun Im、E. R. Bernstein
DOI:10.1021/ja00039a044
日期:1992.6
Conformational perferences for methyl-, ethyl-, propyl-, and isopropyl-substituted pyrazines and pyridines are determined by mass resolved excitation spectroscopy (MRES) and MOPAC 5/PM3 semiempirical calculations. The results of these studies suggest that the conformational behavior of alkyl-substituted pyrazines and pyridines is different from that of alkyl-susbtituted benzenes. Based on the experimental
甲基、乙基、丙基和异丙基取代的吡嗪和吡啶的构象偏好通过质量分辨激发光谱 (MRES) 和 MOPAC 5/PM3 半经验计算确定。这些研究的结果表明,烷基取代的吡嗪和吡啶的构象行为不同于烷基取代的苯。根据本文报道的实验和半经验理论结果以及公布的从头计算,这种差异可归因于烷基取代基的 α-氢原子与环氮原子上相邻的孤对非键电子之间的稳定相互作用