{TAIL ~ 3,7 Diamino phenazine leuco dyes} stabilized in {HEAD ~ the 10 position} with acyl substituents, said acyl substituents being themselves substituted with electron withdrawing groups 
{ TAIL ~ 3,7 Diamino phenazine leuco dyes } stabilized in { HEAD ~ the 10 position } with acyl substituents , said acyl substituents being themselves substituted with electron withdrawing groups
TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH