کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1403697 | 1501809 | 2011 | 5 صفحه PDF | دانلود رایگان |
X-ray measurements of four naphthalene proton sponges have been performed. They include 2,7-di(4-tolylethynyl)-1,8-bis(dimethylamino)naphthalene 4 together with its cation, 2,4-bis(trifluoroacetyl)-1,8-bis(dimethylamino)naphthalenes 16 and 2,6-difluoro-1,3,4,5,7,8-hexakis(dimethylamino)naphthalene 15. It has been disclosed that among all known proton sponge derivatives, compound 16 possesses the largest N⋯N distance and the strongest deviation of the NMe2 groups from the average ring plane while for compound 15 the related parameters are record small. A peculiarity of 2,7-diacetylene 4 is its unusually enhanced basicity contrasting with electron acceptor nature of 4-tolylethynyl group. An origin of the latter phenomena is discussed.
► Four new naphthalene proton sponges were structurally analyzed.
► Proton accepting properties and conformation of NMe2 groups are generalized.
► Ethynyl groups may raise proton sponge’s basicity if adjacent to the basic centers.
► Effective conjugation as stimulus for severe aromatic ring distortions.
Journal: Journal of Molecular Structure - Volume 1005, Issues 1–3, 16 November 2011, Pages 12–16