1 DOF (S)-2-(4-nitrobenzyl)-1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetate 1.000 2 DOE (S)-2-(4-(2-(2-hydroxyethylthio)-acetamido)-benzyl)-1,4,7,10-tetraazacyclododecane-N,N',N'',N'''-tetraacetate 0.800