Crosslinking agent and fluorine-containing aromatic compound

A crosslinking agent comprising a compound represented by a formula (2),

• wherein
• m is an integer from 2 to 6;
• each hydrogen on the benzene ring in the core structure is not substituted or is substituted with a substituent selected from the group consisting of fluorine atom, an alkyl group, a fluoroalkyl group, a cycloalkyl group, a fluorocycloalkyl group, and a substituted or unsubstituted aryl group;
• and
• the —CR1═CR2R3 group is selected from the group consisting of

A crosslinking agent comprising a compound represented by a formula (5),

• wherein
• o is 1;
• q are an integer from 1 to 4;
• in each —CR1═CR2R3, at least one of R1, R2, and R3 is a hydrogen atom, at least one of R1, R2, and R3 is a fluorine atom or a fluoroalkyl group, and any R1, R2, or R3 that is not a hydrogen atom, a fluorine atom, or a fluoroalkyl group is an alkyl group, or a substituted or unsubstituted aryl group,
• a plurality of R1 are identical to or different from each other, a plurality of R2 are identical to or different from each other, and a plurality of R3 are identical to or different from each other;
• each hydrogen on the benzene rings in the core structure is not substituted or is substituted with a substituent selected from the group consisting of fluorine atom, an alkyl group, a fluoroalkyl group, a cycloalkyl group, a fluorocycloalkyl group, and a substituted or unsubstituted aryl group, and
• the —CR1═CR2R3 groups are not —CH═CF2.

A compound represented by a formula (1),

• wherein
• m is an integer from 2 to 6;
• 1 is one;
• in each —CR1═CR2R3, at least one of R1, R2, and R3 is a hydrogen atom, at least one of R1, R2, and R3 is a fluorine atom or a fluoroalkyl group, and any R1, R2, or R3 that is not a hydrogen atom, a fluorine atom, or a fluoroalkyl group is an alkyl group, or a substituted or unsubstituted aryl group;
• a plurality of R1 are identical to or different from each other, a plurality of R2 are identical to or different from each other, and a plurality of R3 are identical to or different from each other;
• each hydrogen on the benzene ring(s) in the core structure is not substituted or is substituted with a substituent selected from the group consisting of fluorine atom, an alkyl group, a fluoroalkyl group, a cycloalkyl group, a fluorocycloalkyl group, and a substituted or unsubstituted aryl group;
• and
• the —CR1═CR2R3 groups are not —CH═CF2.

A compound represented by a formula (2),

• wherein
• m is an integer from 2 to 6;
• each hydrogen on the benzene ring in the core structure is not substituted or is substituted with a substituent selected from the group consisting of fluorine atom, an alkyl group, a fluoroalkyl group, a cycloalkyl group, a fluorocycloalkyl group, and a substituted or unsubstituted aryl group;
• and
• the —CR1═CR2R3 groups are selected from the group consisting of

A compound represented by a formula (5),

• wherein
• o is 1;
• q are an integer from 1 to 4;
• in each —CR1═CR2R3, at least one of R1, R2, and R3 is a hydrogen atom, at least one of R1, R2, and R3 is a fluorine atom or a fluoroalkyl group, and any R1, R2, or R3 that is not a hydrogen atom, a fluorine atom, or a fluoroalkyl group is an alkyl group, or a substituted or unsubstituted aryl group;
• a plurality of R1 are identical to or different from each other, a plurality of R2 are identical to or different from each other, and a plurality of R3 are identical to or different from each other;
• each hydrogen on the benzene rings in the core structure is not substituted or is substituted with a substituent selected from the group consisting of fluorine atom, an alkyl group, a fluoroalkyl group, a cycloalkyl group, a fluorocycloalkyl group, and a substituted or unsubstituted aryl group;
• and
• the —CR1═CR2R3 groups are not —CH═CF2.