Intramolecular hydrogen bonds proton sponges

A.V. Degtyarev et al., 2,7-Disubstituted proton sponges as borderline systems for investigating barrier-free intramolecular hydrogen bonds. Protonated 2,7-bis(trimethylsilyl)-and 2,7-di (hydroxymethyl)-l,8-bis(dimethylamino)naphthalenes. Tetrahedron 64, 6209-6224 (2008)... 

Howard, S.T. (2000) Relationship between basicity, strain, and intramolecular hydrogen bond energy in proton sponges. Journal of the American Chemical Society, 122, 8238-8244. 

Howard, S.T. (2000) Relationship between basicity, strain and intramolecular hydrogen-bond energy in proton sponges. Journal of the American Chemical Society, 122, 8238-8244. Smith, P.B., Dye, J.L., Cheney, J. and Lehn, J.-M. (1981) Proton cryptates. Kinetics and thermodynamics of protonation of the [ 1.1.1 ] macrobicyclic cryptand. Journal of the American Chemical Society, 103, 6044-6048. 

M. Pietrzak et al., 13C detected scalar nitrogen-nitrogen couplings across the intramolecular symmetric NHN hydrogen bond of proton sponge. J. Am. Chem. Soc. 123,4338 1339 (2001)... 

Figure 14.17 labeled systems exhibiting strong intramolecular NHN hydrogen bonds. 28 deprotonated mono-anion of 6-nitro-2,3-dipyrrol-2-ylquinoxaline [59]. 29 protonated mono-cation of 1,6-dimethyl-1,6-diazacyclodecane [59] and 30 of 1,8-bis(dimethylamino)-naphthalene (OMAN, proton sponge) [60]. For comparison, the neutral molecules W,W -diphenyl-6-aminopentafulvene-1-aldimine (1, see... 

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