H2 CH2 CO2 R' where R' is H, or an alkyl group other than t-butyl having from one to four carbon atoms, with the provisos that R11 can be SO3 H or a salt thereof, that, in the foregoing chlorinimines and metal complexes, either R3 or R4 can be a CH2 group or O which, in either case, is bonded to the carbon of the pyrrole ring by a double bond, that, in the foregoing families of compounds which are