The synthesis and characterization of [MCl(3)(N=NC5H4NH)(HN=NC5H4N)] from [MO(4)](-) (where M=Re, Tc) organodiazenido, organodiazene-chelate complexes. The X-ray structure of [ReCl3(N=NC5H4NH)(HN=NC5H4N)]

The reaction of Na[ReO4] with 2-hydrazinopyridine dihydrochloride in methanol gives [ReCl3(N=NC5H4NH) (HN=NC5H4N)] in excellent yields. The neutral, six-coordinate complex contains a pyridinium-diazenido ligand and a bidentate organodiazene ligand chelated through the pyridine nitrogen atom. The IR spectrum of this complex displays a series of strong absorptions in the 1600-1150 cm(-1) region from the organohydrazide ligands. The FAB(+) mass spectrum displays the protonated parent ion of 507 m/z units and the fragment [ReCl2(N=NHC5H4N)(HN=NC5H4N)](+) of 470 m/z. The X-ray structure displays a meridional arrangement of chloride ligands, and the pyridine nitrogen atom of the organodiazene chelate ligand trans to the singly-bent, organodiazenido ligand. The molecular coordination geometry is distorted octahedral. The Re-N bond length to the pyridine nitrogen atom of the organodiazene chelate is 2.164(7) Angstrom, while the Re-N bond to the diazene alpha-nitrogen atom is 1.936(10) Angstrom. The N-N bond length of this ligand is 1.309(11) Angstrom, indicative of multiple bonding within the chelated ligand. The Re-N bond length of the pyridinium-diazenido ligand is 1.741(7) Angstrom and the N-N bond length is 1.253(12) Angstrom, again reflecting the multiple bonding throughout the organodiazenido unit. The bond angle for this linkage is 168.1(8)degrees. Crystal data for ReCl3N6C10H10: triclinic space group P (1) over bar, unit cell dimensions: a = 7.527(2), b = 7.599(2), c = 13.118(3) Angstrom, alpha = 106.55(3), beta = 90.28(3), gamma = 93.83(3)degrees, V = 717.4(4) Angstrom(3), with D-calc = 2.346 Mg m(-3) to give Z = 2. Structure solution based on 2533 reflections converged at R = 3.61. The reaction of ammonium pertechnetate with 2-hydrazinopyridine-dihydrochloride in methanol gives [TcCl3(N=NC5H4NH)(HN=NC5H4N)]. The H-1 NMR spectrum displays inequivalent organohydrazide ligands. The IR spectrum of the technetium complex displays an extended series of absorptions in the 1600-1150 cm(-1) region, analogous to the rhenium complex. The FAB(+) mass spectrum displays the protonated parent ion of 420 m/z as well as the fragment associated with the loss of HCl of 383 m/z. The reaction of the rhenium complex with stoichiometric amounts of triphenylphosphine and a proton scavenger gives [ReCl2(PPh(3)) (N=NC5H4N) (HN=NC5H4N)], an organodiazenido-organodiazene complex in which the phosphine has replaced one of the chloride ligands accompanied by the loss of the pyridinium proton from the organodiazenido ligand.