5',5''-Bis(4-carboxyphenyl)-4'',6'-dimethoxy-[1,1':3',1'':3'',1'''-quaterphenyl]-4,4'''-dicarboxylic acid

[1,1':3',1'':3'',1'''-Quaterphenyl]-4,4'''-dicarboxylic acid, 5',5''-bis(4-carboxyphenyl)-4'',6'-dimethoxy-