and wherein T3 is a timing or linking group which functions by electron transfer down a conjugated chain and is represented by the formula ##STR25## wherein *** denotes the point of attachment to E2 and **** denotes {TAIL ~ the point} of {HEAD ~ attachment} to PUG 
and wherein T3 is a timing or linking group which functions by electron transfer down a conjugated chain and is represented by the formula # # STR25 # # wherein * * * denotes the point of attachment to E2 and * * * * denotes { TAIL ~ the point } of { HEAD ~ attachment } to PUG
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH HEAD HEAD HEAD HEAD HEAD OTH OTH