THE SYNTHESIS AND CHARACTERIZATION OF [TC(SPH)(2)(N=NC5H4N) (HN=NC5H4N)](2), A PARAMAGNETIC DIMER WITH BRIDGING PHENYLTHIOLATE LIGANDS - THE X-RAY STRUCTURE OF [TC(SPH)(2)(N=NC5H4N) (HN=NC5H4N)](2)

The reaction of [TcCl3(N=NC5H4NH)(HN=NC5H4N)] with thiophenol and tria lkylamine in methanol gives [Tc(SPh)(2)(N=NC5H4N)(HN=NC5H4N)](2) in ex cellent yields. The neutral, paramagnetic, doubly thiolato-bridged dim er contains a pyridyldiazenido ligand and a bidentate oganodiazene lig and on each of the technetium atoms, as well as a terminal and a bridg ing phenyl-thiolate ligand. The infrared spectrum displays a series of strong absorptions in the 1600-1150 cm(-1) region from the two organo hydrazide ligands. The fast atom bombardment(+) mass spectrum displays the protonated parent ion {[Tc-2(SPh)(4)(N=NC5H4N)(2)(HN=NC5H4N)(2)]. H}(+) of 1061 m/z and the fragment [Tc-2(SPh)(3)(N=NC5H4N)(2)(HN=NC5H4 N)(2)](+) of 951 m/z. The X-ray structure displays a molecular coordin ation geometry of distorted octahedral. The Tc-N bond length to the py ridine nitrogen atom of the organodiazene chelate is 2.135(8) Angstrom , while the Tc-N bond to the diazene alpha-nitrogen atom is 2.016(8) A ngstrom. The N-N bond length of this ligand is 1.285(11) Angstrom, ind icative of multiple bonding within the chelated ligand. The Tc-N bond length of the pyridyldiazenido ligand is 1.778(10) Angstrom and the N- N bond length is 1.237(11) Angstrom, again reflecting the multiple bon ding throughout the organodiazenido unit. The bond angle for this link age is 174.2(8)degrees. Crystal data for TcS2N6C22H19: orthorhombic sp ace group Pbca; unit cell dimensions: a=15.176(3), b=16.560(5), c=19.8 75(5) Angstrom, V=4995(2) Angstrom(3), with D-cak = 1.408 g cm(-3) to give Z=8. Structure solution based on 2325 reflections converged at R= 0.0753 for (I > 2 sigma(I)). (C) 1998 Elsevier Science S.A.