Reaction of o-phenylenediamine with diacetyl monoxime: characterisation of the product by solid-state 13C and 15N MAS NMR

T Radhakrishnan; P Sreekumari Nair; G A Kolawole; N Revaprasadu; G E Hawkes; M Motevalli; E S Bento; P O'Brien

doi:10.1002/mrc.1923

Reaction of o-phenylenediamine with diacetyl monoxime: characterisation of the product by solid-state 13C and 15N MAS NMR

Magn Reson Chem. 2007 Jan;45(1):59-64. doi: 10.1002/mrc.1923.

Authors

T Radhakrishnan¹, P Sreekumari Nair, G A Kolawole, N Revaprasadu, G E Hawkes, M Motevalli, E S Bento, P O'Brien

Affiliation

¹ Department of Chemistry, University of Zululand, Private Bag X1001, Kwadlangezwa 3886, Kwa Zulu Natal, Republic of South Africa.

PMID: 17103484
DOI: 10.1002/mrc.1923

Abstract

2,3-dimethylquinoxaline (DMQ) and dimethylglyoxime (DMGH2) form a 1:1 hydrogen-bonded complex in the solid state, which is completely dissociated in methanol solution. There are small differences in solid-state 13C shifts between the separated components DMQ and DMGH2 and the complex. The changes in 15N solid-state chemical shifts are more significant: the hydrogen bond imparting a low frequency shift of ca 19 ppm. The effect of direct protonation on the DMQ solid-state 15N shifts was measured, and the experimental 15N data correlated with those from GIAO molecular orbital (MO) calculations.