| 摘要 |
<p>Cyanine dyes are disclosed having a nucleus of the formula: <CHEM> in which; A and B are independently selected from heterocyclic ring nuclei and heterocyclic fused ring nuclei to complete a cyanine dye, m and n independently have values of 0, 1, 2 or 3 with the proviso that 2 </= m + n </= 4, R represents a hydrogen atom, an alkyl group or an aryl group, each of which groups may optionally be substituted, and Q represents those non-metallic atoms necessary to complete a nucleus of a heterocyclic ring, a carbocyclic ring or a carbocyclic or heterocyclic fused ring system. The cyanine dyes of formula (I) may be used to spectrally sensitise silver halide grains to radiation in the wavelength range from 650 nm upwards, especially 700 to 850 nm, to provide infrared-sensitive, silver halide photographic materials which are particularly suitable for use with electronically modulated exposure sources, such as lasers and light emitting diodes.</p> |
