F. You, R.J. Twieg, et al.
Molecular Crystals and Liquid Crystals Science and Technology Section A: Molecular Crystals and Liquid Crystals
Paper
Functionalized azo dyes by direct Ullmann coupling
Abstract
A variety of thermally stable 4-(N,N-diarylamino)-4′-nitroazobenzene dyes can be produced by direct copper-mediated C-N bond formation on preformed amino substituted azo dyes, thus avoiding a troublesome azo coupling step; the products are useful chromophores for high temperature nonlinear optical applications.