R11 is independently selected from {HEAD ~ the group} consisting of alkyl and {TAIL ~ aryl}; and 
consisting of
R11 is independently selected from { HEAD ~ the group } consisting of alkyl and { TAIL ~ aryl } ; and
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL REL OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH