ydroxyl groupsmust be meta or para to the aromatic carbonyl;X is halogen, alkoxy, or hydroxyl, provided that when an X is a hydroxyl groups, X must be meta or para to the aromatic carbonyl;n is an integer from 0 to 4;Y is a divalent linking group, preferably selected from the group consisting of a covalent bond, an oxygen atom (--O--), an amino groups (--NR'-- wherein R is hydrogen or lower alkyl)