O - vs. N -protonation of 1-dimethylaminonaphthalene-8-ketones: formation of a peri N-C bond or a hydrogen bond to the pi-electron density of a carbonyl group
O - vs. N -protonation of 1-dimethylaminonaphthalene-8-ketones: formation of a peri N-C bond or a hydrogen bond to the pi-electron density of a carbonyl group
复制标题
1-二甲基氨基萘-8-酮的 O - 与 N - 质子化：与羰基的π电子密度形成近N-C键或氢键
DOI：
10.1039/c4ce00981a
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发表时间：
2014
期刊：
影响因子：
3.1
通讯作者：
Mercadal N
中科院分区：
文献类型：
--
作者：
Mercadal N
X-射线晶体学和固体核磁共振研究表明，一系列1-二甲氨基萘-8-酮的质子化反应要么导致O质子化，形成长的N-C键，（1.637-1.669 π），或N质子化并与羰基的π表面形成氢键，后者发生在较大的酮基（C（O）R，R =叔丁基和苯基）。固态15 N MAS NMR研究清楚地区分了这两个系列，前者产生了显着更多的去屏蔽共振。这是准确地证实了DFT计算相关的化学位移参数。在母体酮中，X射线晶体学显示，在所有情况下，氮孤对电子都指向羰基。
X-ray crystallography and solid-state NMR measurements show that protonation of a 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 yielding significantly more deshielded resonances. This is accurately corroborated by DFT calculation of the relevant chemical shift parameters. In the parent ketones X-ray crystallography shows that the nitrogen lone pair is directed towards the carbonyl group in all cases.