The characterization of technetium organohydrazide chelate complexes. The synthesis of a technetium phenylimido complex. The X-ray crystal structure of [TcO(SC 6H 2Pr i3) 2(PhNNCON 2HPh)

Abstract

The reaction of the neutral technetium(V) oxo tris(thiolate) complex [TcO(SAr) 3(C 5H 5N)] with (phenylazo)formic acid 2-phenylhydrazide in methanol gives the oxo technetium(V) bis(thiolato) complex [TcO(SAr) 2(PhN 2CONNHPh)] ( 2). The FAB-MS(+) of 2 shows the protonated parent ion and the organohydrazide ligand fragmenting such that the technetium-phenylimido species [TcO(SAr)(NPh)] + is generated. The X-ray crystal structure of 2 shows a distorted square pyramidal coordination geometry and the nitrogen-bound proton on the terminal exocyclic nitrogen of the singly deprotonated, chelated organohydrazide ligand. Crystal data for C 43H 56N 4O 2S 2Tc: triclinic space group P 1 , a = 13.3613(8), b = 14.02768(6), c = 13.0857(6) Å, α = 113.949(4), β = 100.265(4), γ = 76.019(4)°, V = 2166.0(4) Å 3 to give Z = 2. Structure solution and refinement based on 7786 reflections converged at R = 0.040, R w = 0.045. The reaction of the cationic technetium(V) oxo complex (Bu 4N)[TcOCl 4] with (phenylazo)formic acid 2-phenylhydrazide and 1,5-diphenylcarbazide yields the phenylimido complex [TcCl(NPh)PhN 2CON 2HPh) 2] ( 1) which incorporates a phenylimido unit. The infrared spectrum of this species shows a strong band at 1204 cm −1 which has been assigned to v(TcN). The fast atom bombardment mass spectrometric analysis shows the protonated parent ion and a fragmentation profile containing both bis(phenylimido) and tris(phenylimido) technetium species generated through the decomposition of the chelated organohydrazide ligands.