The compound may have {HEAD ~ the formula} 2C L M R. The substructure L may be selected from {TAIL ~ an optionally substituted propenylene group} and trimethylene group  
The compound may have { HEAD ~ the formula } 2C L M R. The substructure L may be selected from { TAIL ~ an optionally substituted propenylene group } and trimethylene group
OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH