wherein the tertiary ligand comprises {HEAD ~ a formula} of {TAIL ~ X2 X3} X4 X5 X6 wherein 
wherein the tertiary ligand comprises { HEAD ~ a formula } of { TAIL ~ X2 X3 } X4 X5 X6 wherein
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH