M. Pietrzak et al., A H-1, C-13 and N-15 NMR investigation of three substituted DMAN derivatives and their monoprotonated salts, J PHYS ORG, 13(1), 2000, pp. 35-38
We report a H-1, C-13 and N-15 NMR investigation of one symmetrically subst
ituted 2,7-dichloro and two unsymmetrically substituted 2-chloro and 4-brom
o DMAN [1,8-bis(dimethylamino)naphthalene] proton sponges and their protona
ted 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(N-15-H-1) and N-15 and H-1 chemical shifts for the nuclei in the [N-8-
H-N1](+) bridge. A further significant NMR parameter is (3)J(H-1-H-1) for t
he bridging proton and the N(CH3)(2) protons. An analysis of the values of
(1)J (N-15-H-1) 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 degrees C, and a change of solv
ent, show that the values of the N-15 chemical shifts and couplings (1)J (N
-15-H-1) and (3)J (H-1-H-1) for the [N8-H-N1](+) bridge are essentially unc
hanged. This shows that the bonding arrangements of the bridge atoms are st
able under these experimental conditions. Copyright (C) 2000 John Wiley & S
ons, Ltd.