{HEAD ~ A compound} 1, wherein said {TAIL ~ compound} is selected from the group consisting of: 
wherein
{ HEAD ~ A compound } 1 , wherein said { TAIL ~ compound } is selected from the group consisting of :
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH REL OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH