The invention provides novel compounds which show high sensitivity to near-infrared rays in the region of 750-950 nm and, when processed to give films and so forth, undergo only slight discoloration and retain high transparency, hence can be used as near-infrared absorbing materials, together with an intermediate thereof. Thus provided are polymethine compounds of the general formula (I):
1
wherein R
1
and R
2
each independently represents a hydrogen atom, an alkyl group or an alkoxy group, R
3
represents an alkyl group, which may optionally be substituted, L represents an alkylene group necessary for the formation of a cyclic structure, X represents a hydrogen atom, a halogen atom or a substituted amino group, and Z represents an acidic residue, as well as near-infrared absorbing materials comprising the same.
该发明提供了一种新型化合物,其在750-950纳米的近红外光区域表现出高灵敏度,当加工成薄膜等材料时,仅发生轻微变色并保持高透明度,因此可用作近红外吸收材料,以及其中间体。因此提供了一般式(I)的聚甲烯化合物:其中R1和R2分别独立表示氢原子、烷基或烷氧基,R3表示烷基,可以选择性地被取代,L表示用于形成环状结构的亚烷基基团,X表示氢原子、卤素原子或取代
氨基团,Z表示酸性残基,以及包含相同化合物的近红外吸收材料。