ISSN:
0009-2940
Keywords:
13C NMR, SCS
;
Substituent effects
;
Imines
;
Isomerization, (E,Z) Schiff bases
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Sterically congested N-(1,1,3,3-tetraalkyl-2-indanylidene)-amines 8-11, N-(cyclopentylidene)anilines 13-17, and two of their salts are described, together with a short synthesis of 2-imino-1,1,3,3-tetramethylindan (5). Some of these imines show rapid (E,Z) equilibration. Positively and negatively charged nitrogen functions (in 6 and 7) cause opposite 1H- and 13C-NMR chemical shift effects along the C = N bond. Chemical shifts are almost equally affected by the lone electron pair and by the imino N-H bond. Substituent-induced chemical shifts (SCS) have been assigned for all syn and anti positions with respect to methyl, phenyl, and 2,6-dimethylphenyl groups at the imino nitrogen atom. The structurally well-defined, rigid imines recommend themselves as new models for the calibration of theoretical approaches to syn/anti-differentiating SCS.
Additional Material:
3 Tab.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19921250911
Permalink
