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