abstract |
The present invention provides a filter for electronic display devices comprising a metal complex of squarylium compound represented by General Formula (I): n n n(wherein R 1 and R 2 may be the same or different and each represents a hydrogen atom, an alkyl group optionally having substituent(s) and the like, R 3 and R 4 may be the same or different and each represents a hydrogen atom, an alkyl group optionally having substituent(s), an aralkyl group optionally having substituent(s) and the like, and M represents a metal atom having coordination function, n represents an integer of 1 to 4). |