1 ##STR2## wherein: X is hydrogen or a coupling-off group, and Y and Z are independentlyselected hydrogen or a substituent;R.sup.1 is hydrogen or a substituent; andeach R is an independently selected substituent with at least one R substituent located in the 2- or 5-position, and n is 1 to 3;provided that substituents may join to form a ring.The invention also provides a coupler composition, a dy