New NIR methine dyes with modified polyene chain belonging to cyanine and t
riphenylmethane groups has been synthesised and tested for the sensitivity
to ammonia. It was found that the dyes are reversibly sensitive to ammonia
and also to some amines in ethanol and ethanol-water solutions. The dyes ma
y be also used as pH indicators in the basic pH region. (C) 1998 Elsevier S
cience S.A. All rights reserved.