Patent ID: 10988494

Abstract:
To provide europium complexes having high photostability.A europium complex expressed with the following formula (A): {wherein, RA and RB are independently a cyclic alkyl group with 3 to 10 carbons, respectively, and RC is a cyclic alkyl group with 3 to 10 carbons or a phenyl group expressed with the following formula (B):  (wherein, XA, XB, AC, XD and XE independently represent a hydrogen atom; a fluorine atom; an alkyl group with 1 to 3 carbon(s); an alkyloxy group with 1 to 3 carbon(s); an aryloxy group with 6 to 10 carbons; a fluoroalkyl group with 1 to 3 carbon(s); a fluoroalkyloxy group with 1 to 3 carbon(s); or a phenyl group that may be substituted with a fluorine atom, an alkyl group with 1 to 3 carbon(s), an alkyloxy group with 1 to 3 carbon(s), a fluoroalkyl group with 1 to 3 carbon(s), a fluoroalkyloxy group with 1 to 3 carbon(s), a fluorophenyl group, a hydroxyl group or a cyano group, respectively);       (wherein, XE represents a hydrogen atom, an alkyl group with 1 to 3 carbon(s), an alkyloxy group with 1 to 3 carbon(s), a fluoroalkyl group with 1 to 3 carbon(s), a fluoroalkyloxy group with 1 to 3 carbon(s), a naphthyl group that may be substituted with a fluorine atom, a pyridyl group that may be substituted with a fluorine atom, or a phenyl group that is expressed with a formula (C):  [wherein, ZA, ZC and ZE independently represent a hydrogen atom, a fluorine atom, an alkyl group with 1 to 3 carbon(s), an alkyloxy group with 1 to 3 carbon(s), a fluoroalkyl group with 1 to 3 carbon(s), a fluoroalkyloxy group with 1 to 3 carbon(s), a phenyl group that may be substituted with a fluorine atom, a hydroxyl group or a cyano group; ZB and ZD independently represent a hydrogen atom or a fluorine atom, respectively], provided, however, that a case where RA, RB and RC are all a phenyl group is excluded), respectively; RD represents a hydrogen atom, a deuterium atom or a fluorine atom; WA and WB independently represent an alkyl group with 1 to 6 carbon(s), a fluoroalkyl group with 1 to 6 carbon(s), a phenyl group, a 2-thienyl group or a 3-thienyl group; and ‘n’ represents an integer of 1 to 3}.