Knowledge of the electron donor strength of different amino groups, which can be affected by other substituents and bridges (rings) present in the molecule, is necessary to explain the properties of aromatic amines. The optimum conformation of aromatic amines is a compromise between the tendency of the nitrogen atom to be pyramidal and its tendency to assume planer configuration in order to maximize the response interaction with the aromatic part of the molecule. Numerous experimental techniques and theoretical calculations allow differentiate the subtituent effect of the amino groups. Although spectroscopic methods (NMR, UV-VIS, IR/Raman, microwave and photoelectron) are helpful to evaluate their donor strength, other data (dipole moment, basicity/reactivity, electron and X-ray diffraction) are complementary and have also been discussed in this review.
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Ryszard Gawinecki, 2001. Evaluation of the Electron Donor Strength of Different Amino Groups. Journal of Applied Sciences, 1: 538-551.
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