If {HEAD ~ the compound} is {TAIL ~ a disulfide}, the disulfide bond is broken and each sulfur is individually bonded to the metal 
If { HEAD ~ the compound } is { TAIL ~ a disulfide } , the disulfide bond is broken and each sulfur is individually bonded to the metal
OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH