Selenomerocyanines and processes for preparation and methods of use and compositions thereof

A compound having the structural formula ##STR16## wherein X is O, S, Se, Te, C(CH.sub.3).sub.2 or NR wherein R is methyl, ethyl, propyl, cyclopropyl, cyclohexyl, phenyl or phenyl substituted by from one to three of methyl, trifluoromethyl, methoxycarbonyl, ethoxycarbonyl, cyano, dimethylamino, methoxy, methylthio, fluoro, chloro, bromo, or iodo;

• Y is alkylene having from two to nine carbon atoms or alkylene having from two to nine carbon atoms interrupted by O, S, NR', CONH or phenylene wherein R' is methyl or phenyl;
• Z.sub.1 and Z.sub.2 are independently H or alkyl having from one to ten carbon atoms;
• m is 0 or 1;
• n is 1, 2 or 3;
• M.sup.+ is pharmaceutically or photographically acceptable cation;
• and
• Ar is a fused aromatic nucleus selected from the group consisting of benzo and naphtho.