R and T are the same or different, being hydrogen, {HEAD ~ a hydrocarbyl group} having from 1 to 12 carbon atoms, or a 1 to 6 heteroatom substituted hydrocarbyl group having from 1 to 12 carbon atoms, wherein said heteroatoms are {TAIL ~ chalcogen}, halogen, or nitrogen 
R and T are the same or different , being hydrogen , { HEAD ~ a hydrocarbyl group } having from 1 to 12 carbon atoms , or a 1 to 6 heteroatom substituted hydrocarbyl group having from 1 to 12 carbon atoms , wherein said heteroatoms are { TAIL ~ chalcogen } , halogen , or nitrogen
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD 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 OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH