摘要:
A bleach catalyst in the form of a ligand of formula (I); wherein Z and Z are independently selected from monocyclic or polycyclic aromatic ring structures optionally containing one or more heteroatoms, each aromatic ring structure being optionally substituted by one or more substituents. Y and Y are independently selected from C, N, O, Si, P and S atoms. A and A are independently selected from hydrogen, alkyl, alkenyl and cycloalkyl (each of alkyl, alkenyl and cycloalkyl being optionally substituted, electron donating groups and electron withdrawing groups); i and j are selected from 0, 1 and 2 to complete the valency of the groups Y and Y each of Q -Q is independently selected from groups of formula (a); wherein 10 > a + b + c + d > = 2; each Y is independently selected from O, S, SO, SO2, (G )(G )N-C(O), aryl, heteroaryl, P and P(O) each of A -A is independently selected from the groups hereinbefore defined for A and A ; ion pairs, complexes and the use of such ligands, ion pairs and complexes in cleaning and/or bleaching compositions are also described.