Compound, and preparation method and use thereof

A compound having a structure of formula I:

• wherein R1 and R2 are independently selected from H, halogen, a substituted or unsubstituted C1-C6 alkyl, a substituted or unsubstituted C1-C6 alkoxy, —O—R7, a substituted or unsubstituted C6-C30 aryl, or a substituted or unsubstituted C4-C20 heteroaryl;
• R7 is independently selected from a substituted or unsubstituted C1-C6 alkyl, a substituted or unsubstituted C6-C20 aryl, or a substituted or unsubstituted C4-C20 heteroaryl;
• a and b are independently selected from any integer of 0 to 3;
• a heteroatoms in the heteroaryl is selected from any one or more of N, O, P, or S;
• R3, R4, R5, and R6 are independently selected from H, halogen, nitro, a substituted or unsubstituted C1-C6 alkyl, cyano, sulfonyl, acyl, or carboxyl;
• and
• c and d are independently selected from any integer of 0 to 3.