Light emitting material, delayed fluorescent emitter, organic light emitting device, and compound

1. A compound represented by the following formula (1′):

wherein in the formula (1′), X′ represents an oxygen atom or a sulfur atom; and R 1′ to R 8′ each independently represent a hydrogen atom, a hydroxyl group, a halogen atom, a cyano group, an alkyl group having from 1 to 20 carbon atoms, an alkoxy group having from 1 to 20 carbon atoms, an alkylthio group having from 1 to 20 carbon atoms, an alkyl-substituted amino group having from 1 to 20 carbon atoms, an acyl group having from 2 to 20 carbon atoms, an aryl group having from 6 to 40 carbon atoms, a heteroaryl group having from 3 to 40 carbon atoms, an alkenyl group having from 2 to 10 carbon atoms, an alkynyl group having from 2 to 10 carbon atoms, an alkoxycarbonyl group having from 2 to 10 carbon atoms, an alkylsulfonyl group having from 1 to 10 carbon atoms, a haloalkyl group having from 1 to 10 carbon atoms, an amide group, an alkylamide group having from 2 to 10 carbon atoms, a trialkylsilyl group having from 3 to 20 carbon atoms, a trialkylsilylalkyl group having from 4 to 20 carbon atoms, a trialkylsilylalkenyl group having from 5 to 20 carbon atoms, a trialkylsilylalkynyl group having from 5 to 20 carbon atoms, a nitro group, or a group represented by any one of the following formulae (2′) to (6′), provided that at least one of R 1′ to R 8′ each independently represent a group represented by any one of the following formulae (2′) to (6′), and such a case is excluded that R 2′ and R 7′ each represent a group represented by the following formula (2′), and all R 21′ to R 28′ represent hydrogen atoms,

wherein in the formulae (2′) to (6′), L 20′ , L 30′ , L 40′ , L 50′ and L 60′ each independently represent a single bond or a divalent linking group selected from an alkenylene group, an alkynylene group, an arvlene group, a thiophenediyl group, and a linking group formed of a combination of these groups, and the group represented by any one of the formulae (2′) to (6′) is bonded to the cyclic structure of the formula (1′) through L 20′ , L 30′ , L 40′ , L 50′ or L 60′ ; and R 21′ to R 28′ , R 31′ to R 38′ , R 3a′ , R 3b′ , R 41′ to R 48′ , R 4a′ , R 51′ to R 58′ , and R 61′ to R 68′ each independently represent a hydrogen atom, a hydroxyl group, a halogen atom, a cyano group, an alkyl group having from 1 to 20 carbon atoms, an alkoxy group having from 1 to 20 carbon atoms, an alkylthio group having from 1 to 20 carbon atoms, an alkyl-substituted amino group having from 1 to 20 carbon atoms, an acyl group having from 2 to 20 carbon atoms, an aryl group having from 6 to 40 carbon atoms, a heteroaryl group having from 3 to 40 carbon atoms, an alkenyl group having from 2 to 10 carbon atoms, an alkynyl group having from 2 to 10 carbon atoms, an alkoxycarbonyl group having from 2 to 10 carbon atoms, an alkylsulfonyl group having from 1 to 10 carbon atoms, a haloalkyl group having from 1 to 10 carbon atoms, an amide group, an alkylamide group having from 2 to 10 carbon atoms, a trialkylsilyl group having from 3 to 20 carbon atoms, a trialkylsilylalkyl group having from 4 to 20 carbon atoms, a trialkylsilylalkenyl group having from 5 to 20 carbon atoms, a trialkylsilylalkynyl group having from 5 to 20 carbon atoms, a nitro group, or a group represented by any one of the formulae (2′) to (6′), provided that R 3a′ and R 3b′ may be bonded to each other to form a cyclic structure selected from a fluorene ring, a xanthene ring and a thioxanthene ring.