The synthesis and characterization of [Tc(SPh) 2(NNC 5H 4N)(HNNC 5H 4N)] 2, a paramagnetic dimer with bridging phenylthiolate ligands. The X-ray structure of [Tc(SPh) 2(NNC 5H 4N)(HNNC 5H 4N)] 2

Abstract

The reaction of [TeCl 3(NNC 5H 4NH)(HNNC 5H 4N)] with thiophenol and trialkylamine in methanol gives [Tc(SPh) 2(NNC 5H 4N)(HNNC 5H 4N)] 2 in excellent yields. The neutral, paramagnetic, doubly thiolato-bridged dimer contains a pyridyldiazenido ligand and a bidentate organodiazene ligand on each of the technetium atoms, as well as a terminal and a bridging phenyl-thiolate ligand. The infrared spectrum displays a series of strong absorption in the 1600-1150 cm 1 region from the two organohydrazide ligands. The fast atom bombardment (+) mass spectrum displays the protonated parent ion {[Te 2(SPh) 4(NNC 5H 4N) 2(HNNC 5H 4N) 2]·H} + of 1061 m/ z and the fragment [Te 2(SPh) 3(NNC 5H 4N) 2(HNNC 5H 4N) 2] + of 951 m/ z. The X-ray structure displays a molecular coordination geometry of distorted octahedral. The TeN bonnd length to the pyridine nitrogen atom of the organodiazene chelate is 2.135(8) A, while the TeN bond to the diazene α-nitrogen atom is 2.016(8) A. The NN bond length of this ligand is 1.285(11) A, indicative of multiple bonding within the chelated ligand. The TeN bond length of the pyridyldiazenido ligand is 1.778(10) A and the NN bond length is 1.237(11) A, again reflecting the multiple bonding throughout the organodiazenido unit. The bond angle for this linkage is 174.2(8)″. Crystal data for TeS 2N 6C 22H 19; orthorhombic space group Pbca; unit cell dimensions: a = 15.176(3), b = 16.560(5), c = 19.875(5) A ̊ V = 4995(2) A ̊ , with D = 1.408 g cm 1 to give Z = 8. Structure solution based on 2325 reflections converged at R = 0.0753 for ( I · 2 σ( I)).