This invention provides {HEAD ~ 3,7 diamino phenazine leuco dyes} with {TAIL ~ acyl substituents} in the 10 position, said acyl substituents being themselves substituted with electron withdrawing groups 
with
This invention provides { HEAD ~ 3,7 diamino phenazine leuco dyes } with { TAIL ~ acyl substituents } in the 10 position , said acyl substituents being themselves substituted with electron withdrawing groups
OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH