Synthesis and structural characterization of novel neutral fac-M(CO)3(NSO) complexes (M=Re, 99mTc) with N-acetylcysteine derivatives as tridentate NSO ligands
The reaction of [NEt4](2)[Re(CO)(3)Br-3] with equimolar amount of a tridentate NSO ligand in methanol leads to the formation of neutral tricarbonyl rhenium(I) complexes of the general formula Re(CO)(3)(NSO), where the NSO ligand is o-C5H4N-CH2CH2-S-CH2CH(NHCOCH3)COOH (L1H), complex 1 or o-C5H4N-CH2CH2-S-C(CH3)(2)CH(NHCOCH3)COOH (L2H), complex 2. Both complexes have been characterized by elemental analysis and spectroscopic methods, while complex 2 has also been characterized by X-rays analysis. At technetium-99m level, the corresponding fac-[Tc-99m(CO)(3)(NSO)] complexes 3 and 4, were obtained in high yield by reacting ligands L1H or L2H with the fac-[Tc-99m(CO)(3)(H2O)(3)](+) precursor in water. Their structure was established by chromatographic comparison to the prototype rhenium complex using high-performance liquid chromatographic techniques. (C) 2009 Elsevier Ltd. All rights reserved.