<i>O</i>-<i>vs. N</i>-protonation of 1-dimethylaminonaphthalene-8-ketones: formation of a<i>peri</i>N–C bond or a hydrogen bond to the pi-electron density of a carbonyl group
作者:Nerea Mercadal、Stephen P. Day、Andrew Jarmyn、Mateusz B. Pitak、Simon J. Coles、Claire Wilson、Gregory J. Rees、John V. Hanna、John D. Wallis
DOI:10.1039/c4ce00981a
日期:——
series of 1-dimethylaminonaphthalene-8-ketones leads either to O protonation with formation of a long N–C bond (1.637–1.669 Å) between peri groups, or to N protonation and formation of a hydrogen bond to the π surface of the carbonyl group, the latter occurring for the larger ketone groups (C(O)R, R = t-butyl and phenyl). Solid state 15N MAS NMR studies clearly differentiate the two series, with the former
X射线晶体学和固态NMR测量表明,一系列1-二甲基氨基萘8-酮的质子化导致O质子化,在周边基团之间形成长的N–C键(1.637–1.669Å),或者N质子化并在羰基的π表面形成氢键,后者出现在较大的酮基(C(O)R,R =叔丁基和苯基)上。固态15N MAS NMR研究清楚地区分了这两个系列,前者产生的屏蔽效应明显更多。通过相关化学位移参数的DFT计算可以准确地证实这一点。在母体酮中,X射线晶体学分析表明,在所有情况下,氮孤对都指向羰基。