ISSN:
0018-019X
Keywords:
Chemistry
;
Organic Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
Since we found certain structural features of triaziridine (1) obtained by MNDO calculations to be in qualitative agreement with those derived earlier from ab initio calculations, we used the MNDO method to derive properties of formyltriaziridine (2) and 1-formyl-2,3-diisopropyltriaziridine (3) as models for the preparatively known 2,3-dialkyl-triaziridine-1-carboxylates 4 and 5. The main results are: (a) The triaziridine N-atoms with H, alkyl, or formyl as substituents (see 2 and 3) are pyramidal. N(1) carrying the formyl group is flatter than N(2) and N(3) with H or alkyl substitent. Bond lengths and angles at N(2) and N(3) are almost identical with those calculated for the N-atoms of 1. (b) The MNDO inversion barriers at the H-substituted N(2) and N(3) of 2 are higher than those at the formyl-substituted N(1), but similar to the ab initio barriers at the N-atoms of 1. (c) The MNDO inversion barriers at N(1) of 2 and 3 are 53 to 92 kJ/mol, whereas the rotation barriers around the N(1)-C(4) bond are 7 to 23 kJ/mol; thus, the previously observed dynamic NMR phenomena in trans-2,3-diisopropyltriaziridine-carboxylates (5) can now be assigned to the slowing down of N(1) inversion rather than N(1)-C(4) rotation.
Additional Material:
1 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/hlca.19860690618
