Compounds of the invention are of the formula (I)； wherein: is a double bond and X is C； or is a single bond and X is N, CH or CQR1； and wherein: n is 1 to 10； R is H or QR1； each R&prime； is independently selected from H and QR1； each Q is independently selected from a bond, CO, NH, S, SO, SO2 or O； each R1 is independently selected from C1-C10 alkyl, C2-C10 alkenyl, C2-C10 alkynyl, substituted or unsubstituted aryl or heteroaryl, acyl, C1-C10 cycloalkyl, halogen, C1-C10 alkylaryl or C1-C10 heterocycloalkyl； L is a nitrogen-containing heteroaryl； and W is a zinc-chelating residue； or a pharmaceutically acceptable salt thereof. The compounds are useful in therapy.
