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