Organic salt compound, and optical recording material and optical recording medium using the organic salt compound

An organic salt compound consisting of a monomethine cyanine cation represented by formula (I) and an azomethine complex anion represented by formula (IV):

• wherein X represents an oxygen atom, sulfur atom, a selenium atom, or —NY3—;
• R1 and R2 each independently represent a group represented by formula (II) shown below, a group represented by formula (II′) shown below, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, or an arylalkyl group having 7 to 30 carbon atoms, and R1 and R2 may be taken together to form a 3- to 6-membered alicyclic group;
• R3, R4, R5, and R6 each independently represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, or an arylalkyl group having 7 to 30 carbon atoms, and R4 and R5 may be taken together to form a 6-membered ring;
• Y1, Y2, and Y3 each independently represent an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, or an arylalkyl group having 7 to 30 carbon atoms, or a group represented by formula (III) shown below;
• R7, R8, R9, and R10 each independently represent a hydrogen atom, a hydroxyl group, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, an arylalkyl group having 7 to 30 carbon atoms, a halogen atom, a nitro group, or a cyano group, and adjacent two of R7, R8, R9, and R10 may be taken together to form a 5- or 6-membered ring;
• and
• the methylene moiety of the alkyl group and the arylalkyl group may be interrupted by —O—, —S—, —CO—, —COO—, —OCO—, —SO2—, —NH—, —CONH—, —NHCO—, —N═CH—, or —CH═CH—;
• wherein, in formula (II), the bond between G and T is a double bond, a conjugated double bond, or a triple bond;
• G represents a carbon atom;
• T represents a carbon atom, an oxygen atom, or a nitrogen atom;
• w represents a number from 0 to 4;
• x, y, and z each represent, 0 or 1, provided that, when T is oxygen, y=z=0, and, when T is nitrogen, y+z=0 or 1;
• R01, R02, R03, and R04 each independently represent a hydrogen atom, a hydroxyl group, a nitro group, a cyano group, a halogen atom, or an optionally substituted alkyl group having 1 to 4 carbon atoms of which the methylene moiety may be interrupted by —O— or —CO—;
• and R01 and R04 may be taken together to form a cycloalkene ring or a heterocyclic ring;
• and
• in formula (II′), the bond between G′ and T′ is a double bond or a conjugated double bond;
• G′ represents a carbon atom;
• T′ represents a carbon atom or a nitrogen atom;
• w′ represents a number of 0 to 4;
• R01′ represented a hydrogen atom, a hydroxyl group, a nitro group, a cyano group, a halogen atom, an optionally substituted alkyl group having 1 to 4 carbon atoms of which the methylene moiety may be interrupted by —O— or —CO—;
• and the ring containing G′ and T′ is a 5-membered ring optionally containing a hetero atm, a 6-membered ring optionally containing a hetero atom, a quinoline ring, an isoquinoline ring, or an anthraquinone ring, each optionally substituted with a halogen atom, a hydroxyl group, a nitro group, a cyano group, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms;
• wherein Ra, Rb, Rc, Rd, Re, Rf, Rg, Rh, and Ri each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms of which the methylene moiety may be interrupted by —O— or —CO—;
• Q represents a direct bond or an optionally substituted alkylene group having 1 to 8 carbon atoms of which the methylene moiety may be interrupted by —O—, —S—, —CO—, —COO—, —OCO—, —SO2—, —NH—, —CONH—, —NHCO—, —N═CH—, or —CH═CH—;
• and M represents Fe, Co, Ni, Ti, Cu, Zn, Zr, Cr, Mo, Os, Mn, Ru, Sn, Pd, Rh, Pt, or Ir;
• wherein M′ represents Fe, Co, Ni, Cu, Cr, Mo, Os, Mn, Ru, Sn, Pd, Rh, Pt, Al, or Ir;
• R11, R12, R13, R14, R15, R16, R17, R18, R19, R20, R21, R22, R23, R24, R25, and R26 each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 30 carbon atoms, an arylalkyl group having 7 to 30 carbon atoms, a nitro group, a cyano group, or —NRR′;
• R and R′ each represent an alkyl group having 1 to 4 carbon atoms;
• and any adjacent two of R11 through R26 may be taken together to form a 5- or 6-membered ring.