{HEAD ~ R5} is ##STR72## R9 is independently selected from the group consisting of alkyl and {TAIL ~ arylalkyl} 
{ HEAD ~ R5 } is # # STR72 # # R9 is independently selected from the group consisting of alkyl and { TAIL ~ arylalkyl }
HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL