R3 is {HEAD ~ H}, {TAIL ~ SO3 X}, halogen, CN, NO2, or L SC  
R3 is { HEAD ~ H } , { TAIL ~ SO3 X } , halogen , CN , NO2 , or L SC
OTH OTH HEAD HEAD HEAD HEAD HEAD OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH