| abstract |
An infrared absorbent comprising alpha -diimine metal complex is disclosed. With the use of the infrared absorbent, there is provided an infrared absorbing material capable of absorbing a near-infrared light having a wavelength of 700-1500 nm and a far-infrared light. The infrared absorbent has a good fastness to heat and light. The infrared absorbing material is suitable for an optical filter and optical information recording medium. |