Conformational behaviour of hydroxamic acids: ab initio and structural studies

1996; Royal Society of Chemistry; Issue: 12 Linguagem: Inglês

10.1039/p29960002673

ISSN

2050-8239

Autores

David A. Brown, R. Coogan, N.J. Fitzpatrick, W.K. Glass, Dau E. Abukshima, Loreto Shiels, Markku Ahlgrén, Kimmo Smolander, Tuula T. Pakkanen, Tapani A. Pakkanen, Mikael Peräkylä,

Tópico(s)

Crystal structures of chemical compounds

Resumo

The conformational behaviour of a series of monohydroxamic acids, p-RC6H4CONR′OH (R = Me, R′= H, Me; R = MeO, R′= H, Me; R = NO2, R′= H), and a series of dihydroxamic acids, (CH2)n(CONR′OH)2(n= 3–8, 10, R′= H and n= 7, R′= Me), in methanol, DMSO and chloroform and in the solid state has been examined using IR and NMR spectroscopy. X-Ray crystal structure determinations of p-MeC6H4CONMeOH and the monohydrate of glutarodihydroxamic acid (n= 3) together with ab initio molecular orbital calculations for several hydrated and unhydrated hydroxamic acids have been performed. Hydrogen bonding effects are shown to be important in both the solid state and solution. The cis(Z) conformation of the hydroxamate group(s)(CONHOH) is preferentially stabilized by hydrogen bonding with water molecules.

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