S-(2-(2′-pyridyl)ethyl)mercaptoacetic acid and S-(2-(2′-pyridyl)ethyl)mercaptopropionic acid as ligands for the 'fac-M(CO)3+' (M = Re,99mTc) core

摘要

Two new high affinity tridentate NSO ligands that form stable neutral complexes, respectively, withthe [M(CO)3(H2O)3]+ (M = Tc or Re) synthons are presented. The chemistry of the reaction of the ligands S-(2-(2′-pyridyl)ethyl)mercaptoacetic acid L1H and S-(2-(2′-pyridyl)ethyl) mercaptopropionic acid L2H with the[NEt4]2[Re(CO)3Br3] was studied. The reaction of [NEt4]2[Re(CO)3Br3] with the L1H in methanol with NaOH,leads to the formation of the expected [Re(CO)3(NSO)] complex. At technetium-99m level, the correspondingcomplex fac-[99mTc(CO)3(NSO)], was obtained by heating the L1H with the fac-[99mTc(CO)3(H2O)3]+ precursorat 70oC in water. The reaction of [NEt4]2[Re(CO)3Br3] with the NSO L2H in methanol with the presence ofNaOH, leads to the formation of a [Re(CO)3(NSO)] complex, practically of the same structure as [Re(CO)3(L1)].