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A 1 H, 13 C and 15 N NMR investigation of three substituted DMAN derivatives and their monoprotonated salts
Author(s) -
Pietrzak Mariusz,
Stefaniak Lech,
Pozharskii Alexander F.,
Ozeryanskii Valery A.,
NowickaScheibe Joanna,
Grech Eugeniusz,
Webb Graham A.
Publication year - 2000
Publication title -
journal of physical organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.325
H-Index - 66
eISSN - 1099-1395
pISSN - 0894-3230
DOI - 10.1002/(sici)1099-1395(200001)13:1<35::aid-poc202>3.0.co;2-n
Subject(s) - chemistry , tautomer , chemical shift , protonation , proton nmr , proton , carbon 13 nmr , naphthalene , computational chemistry , solvent , stereochemistry , organic chemistry , ion , physics , quantum mechanics
We report a 1 H, 13 C and 15 N NMR investigation of one symmetrically substituted 2,7‐dichloro and two unsymmetrically substituted 2‐chloro and 4‐bromo DMAN [1,8‐bis(dimethylamino)naphthalene] proton sponges and their protonated salts. From a consideration of the NMR data reported we conclude, that the most sensitive parameters for investigating compounds of this kind are 1 J ( 15 N– 1 H) and 15 N and 1 H chemical shifts for the nuclei in the [N8–H–N1] + bridge. A further significant NMR parameter is 3 J ( 1 H– 1 H) for the bridging proton and the N(CH 3 ) 2 protons. An analysis of the values of 1 J ( 15 N– 1 H) for the studied compounds is consistent with the view that in the investigated system equilibrium between two tautomeric forms occurs. A study at temperatures between 27 and −40 °C, and a change of solvent, show that the values of the 15 N chemical shifts and couplings 1 J ( 15 N– 1 H) and 3 J ( 1 H– 1 H) for the [N8–H–N1] + bridge are essentially unchanged. This shows that the bonding arrangements of the bridge atoms are stable under these experimental conditions. Copyright © 2000 John Wiley & Sons, Ltd.