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