{HEAD ~ R3} is 1 3 groups independently selected from the group consisting of lower alkyl, lower alkoxy, COOH, NO2, NR4 R5, OH or {TAIL ~ halogeno} 
{ HEAD ~ R3 } is 1 3 groups independently selected from the group consisting of lower alkyl , lower alkoxy , COOH , NO2 , NR4 R5 , OH or { TAIL ~ halogeno }
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 TAIL TAIL TAIL TAIL TAIL