An insight into the mechanism of the cellulose dyeing process, part 1: Modelling azo-systems in azo-linked aromatics and dyes

Flower, K.R.; Hamlin, J.D.; Whiting, A.

Abstract

Molecular modelling has been used to model the three-dimensional structure of azo-containing aryl systems and in particular, azo-dyes such as Procion Red MX-5B. These simulations look in detail at the dynamics of the azo-linkage and the effect of an ortho-phenol function. In this paper we show that the planar arrangement of the C-N=N-C potentially delocalised sp(2)-hybridised system is not encountered exactly in the systems examined; a transoid-arrangement of the azo-linkage allows dihedrals to approach close to 180degrees, however, a cisoid-arrangement can engender greater deformation producing dihedral-, around 30degrees away from planarity. Hence, intra-molecular repulsions are capable of easily distorting the azo-linkages producing a range of dihedral geometries which depend strongly on other substituents around the molecular framework.

Citation

Flower, K., Hamlin, J., & Whiting, A. (2002). An insight into the mechanism of the cellulose dyeing process, part 1: Modelling azo-systems in azo-linked aromatics and dyes. Molecular Simulation, 28(12), 1031-1047

• Journal Article Type: Article
• Publication Date: 2002-12
• Journal: Molecular Simulation
• Print ISSN: 0892-7022
• Publisher: Taylor and Francis Group
• Peer Reviewed: Peer Reviewed
• Volume: 28
• Issue: 12
• Pages: 1031-1047