40496-93-3Relevant academic research and scientific papers
17O NMR Study of Steric Interactions in Hindered N-Substituted Imides
Baumstark, A.L.,Dotrong, M.,Oakley M.G.,Stark, R.R.,Boykin, D.W.
, p. 3640 - 3643 (1987)
17O NMR spectroscopic data (natural abundance in acetonitrile at 75 deg C) were obtained for a series of N-substituted phthalimides (1-11),a series of N-substituted succinimides and maleimides (12-19),and N-substituted phthalamides (20-22).The 17O NMR data showed large deshielding effects as the steric bulk of the N-substituent increased ; introduction of a 3-substituent in the phthalimide series produced additional deshielding.The deshielding effects of 3-substitution and N-substitution in the phthalimides were found to be roughly additive.The results correlated with in-plane bond angle distortions (X-ray results and molecular mechanics calculations.)The results for N-arylphthalimides showed that the aromatic ring was rotated out of the plane (torsion angle effect) in those cases.
(17)O NMR SPECTROSCOPIC STUDY OF STERIC HINDRANCE IN PHTHALIC ANHYDRIDES AND PHTHALIDES
Baumstark, A. L.,Balakrishnan, P.,Boykin, D. W.
, p. 3079 - 3082 (1986)
(17)O NMR data for sterically hindered phthalic anhydrides and phthalides showed unusual deshielding effects which were correlated with in-plane bond angle distortions (X-ray results and MM2 calculations); indicative of van der Waals repulsions.
