Dimerization of Cibacron Blue F3GA and other dyes: influence of salts and temperature

The synthesis of 2,8-diamino-5,10-dihydro-10-hydroxy-5-methylphenophosphazine 10oxide as a possible replacement for the benzidine moiety in some disazo dyes and the use of this new diamine in the preparation of direct dyes were undertaken. The dyes obtained were applied to cotton to give purple to brilliant blue shades, and their structures were confirmed using negative ion electrospray mass spectrometry.