{TAIL ~ The compound} 11, wherein Z1 and {HEAD ~ Z2} are each independently a single bond or alkylene 
{ TAIL ~ The compound } 11 , wherein Z1 and { HEAD ~ Z2 } are each independently a single bond or alkylene
TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH