ISSN:
0009-2940
Keywords:
1-Azapentadienyllithium compounds
;
Structure in solution
;
Calculations, ab initio, MNDO
;
Chemistry
;
Inorganic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
On the Structures of 1-Azapentadienyllithium Compounds1-Azapentadienyllithium compounds 2-6 have been prepared by deprotonation of the α,β-unsaturated imines 1 with lithium diisopropylamide. Their structures in THF solution at various temperatures have been studied by 1H- and 13C-NMR spectroscopy. All N-alkyl-substituted derivatives 2 - 5 adopt W conformations of the 1-azapentadienyl unit. The N-tert-butylsubstituted compound 2 shows an (E)-configurated N=C- bond, whereas compounds 3 -5 prefer (Z)-N=C configurations. According to NOE experiments, the triphenyl system 6 has a U-shape structure, probably because of steric interactions of the phenyl substituents. 13C-shifts of the 1-azapentadienyl carbon atoms are discussed in terms of HOMO coefficients. The experimental structural results are compared with theoretical data obtained by MNDO and ab initio calculations for the corresponding anions. MNDO results are also given for monomeric 1-azapentadienyllithium conformers 11.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/cber.19911240432
Permalink
