The synthesis of nitrosyl complexes of technetium with sulfur-containing cores

Abstract

Abstract The reaction of [Tc(NO)Cl 2 (PPh 3 ) 2 (NCCH 3 )] with 1 equiv. of potassium alkylxanthate in CH 2 Cl 2 yields complexes of the type [Tc(NO)Cl(PPh 3 ) 2 (S 2 COiBu)], in which the weakly coordinated acetonitrile ligand and one of the chloride ligands have been replaced by the bidentate, monoanionic xanthate ligand. The 1 H NMR spectrum of this complex displays equivalent triphenylphosphine ligands, indicating mutually trans coordination geometry. The IR spectrum of this complex displays the absorption associated with ν(NO) at 1702 cm −1 from the linearly coordinated nitrosyl ligand. The FAB (+) mass spectrum of this complex contains the parent ion of 837 m / z which corresponds to [Tc(NO)Cl(PPh 3 ) 2 (S 2 COiBu)] + plus various fragments associated with the loss of the chloride and phosphine ligands. The reaction of [Tc(NO)Cl 2 (PPh 3 ) 2 (NCCH 3 )] with excess potassium alkylxanthate in CH 2 Cl 2 yields complexes of the type [Tc(NO) (PPh 3 ) (S 2 COiBu) 2 ], in which two, bidentate alkylxanthate ligands have been incorporated into the reaction product. The IR spectrum of this complex displays the absorption from ν(NO) at 1701 cm −1 which indicates a linearly coordinated nitrosyl ligand. The FAB(+) mass spectrum of the species displays the parent ion of 689 m / z which corresponds to [Tc(NO) (PPh 3 ) (S 2 COiBu) 2 ] + . The 1 H NMR spectrum of this species displays inequivalent alkylxanthate ligands which indicates that the phosphine and nitrosyl ligands are coordinated in a cis conformation. The analogous reaction chemistry of [Tc(NO)Cl 2 (PPh 3 ) 2 (NCCH 3 )] with the potentially bidentate ligand 2-mercaptopyridine is also presented.