In:
Canadian Journal of Chemistry, Canadian Science Publishing, Vol. 76, No. 8 ( 1998-08-01), p. 1174-1179
Abstract:
The cyclic stannoxane obtained from N-methyldiethanolamine and dibutyltin oxide reacts with 1H-pyrazole-3,5-dicarbonyl dichloride to afford the new 26-membered diaza tetraester crown 3. In neutral medium, the above crown forms 1:2 solid dinuclear complexes with phenethylamine (3a) and homoveratrylamine (3b), which, after crystallization from acetonitrile, were isolated in high yield (90% and 85%, respectively). The 3, 3a, and 3b structures were identified from their analytical and spectroscopic ( 1 H, 13 C NMR, and MS (FAB)) data. The spectroscopic properties of 3a and 3b are demonstrating that, in each complexation centre, simultaneously to the strong participation of the four pyrazole nitrogens, an additional weaker interaction between the aliphatic nitrogen of the side chain and the amine is involved. Comparison of the total interaction energies calculated (GenMol software) for phenethylamine-derived complex (3a) and homoveratrylamine-derived one (3b) suggests that the o-dimethoxy substitution of the guest aromatic ring could be improving the stability of 3b in relation to 3a.Key words: diazacrown, 1H-pyrazole, dinuclear, complexes, phenethylamines.
Type of Medium:
Online Resource
ISSN:
0008-4042
,
1480-3291
Language:
English
Publisher:
Canadian Science Publishing
Publication Date:
1998
detail.hit.zdb_id:
1482256-8
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