2-Mercapto-methyltetrazolate, Smetetraz Β± , acts as monoanionic, monodentate ligand in a number of technetium compounds. Anionic Tc V complexes of the types [TcO(Smetetraz) 4 ] Β± and [TcN(Smetetraz) 4 ] 2Β± are formed when (Bu 4 N)[Tc V OCl 4 ] or (Bu 4 N)[Tc VI NCl 4 ], respectively, react with Na(Smetetraz). Reduction of the metal takes place in the latter case. (Bu 4 N) 2 [TcN(Smetetraz) 4 ] crystallises in the monoclinic space group Pc (a = 9.701(5), b = 17.570(5), c = 16.821(10) A Γ , b = 96.50( 3)Β°, Z = 2). The Tc atom is situated 0.580(3) A Γ above the basal plane of a square pyramid which is formed by the sulfur atoms and the nitrido ligand as its apex. The TcΒ±S bond lengths lie between 2.384(3) and 2.410(3) A Γ .
[Tc(PPh 3 )(Smetetraz) 3 (CH 3 CN)] is formed during the reaction of [TcCl 3 (PPh 3 ) 2 (CH 3 CN)] with NaSmetetraz as blue needles with co-crystallised solvent toluene (space group C2/c, a = 24.188(4), b = 14.373(1), c = 25.617(5) A Γ , b = 109.48(1)Β°, Z = 8). The metal atom is coordinated by PPh 3 and CH 3 CN in the axial position of a trigonal bipyramid. All three aryl rings are on the sterically less strained side of the plane defined by the sulfur atoms. The TcΒ±S bond lengths range between 2.233(2) and 2.247(2) A Γ .