All substituents of the compounds of the invention may be the same, all substituents may be different, or {HEAD ~ any combination} of {TAIL ~ substituents} may be the same or different 
of
All substituents of the compounds of the invention may be the same , all substituents may be different , or { HEAD ~ any combination } of { TAIL ~ substituents } may be the same or different
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH