L1, L2 and L {HEAD ~ each} independently represent the single bond, a substituted or unsubstituted arylene group having 6 to 60 nuclear carbon atoms, a substituted or unsubstituted heteroarylene group having 3 to 60 nuclear carbon atoms or {TAIL ~ a substituted or unsubstituted fluorenylene group} 
independently represent
L1 , L2 and L { HEAD ~ each } independently represent the single bond , a substituted or unsubstituted arylene group having 6 to 60 nuclear carbon atoms , a substituted or unsubstituted heteroarylene group having 3 to 60 nuclear carbon atoms or { TAIL ~ a substituted or unsubstituted fluorenylene group }
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL 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 OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL