3,3'''-Dihydroxy-2',2'',5',5''-tetramethyl-[1,1':4',1'':4'',1'''-quaterphenyl]-4,4'''-dicarboxylic acid

3,3'''-Dihydroxy-2',2'',5',5''-tetramethyl-[1,1':4',1'':4'',1'''-quaterphenyl]-4,4'''-dicarboxylic acid,