T. Nicholson et al., THE SYNTHESIS, CHARACTERIZATION AND X-RAY CRYSTAL-STRUCTURE OF THE RHENIUM ORGANODIAZENIDO, ORGANODIAZENE COMPLEX [RECL2(PPH(3))(N=NC5H4N)(HN=NC5H4N)], Inorganica Chimica Acta, 252(1-2), 1996, pp. 427-430
The reaction of the Re(III) complex [ReCl3(N=NC5H4NH)(HN=NC5H4N)] (1)
with triphenylphosphine and a proton scavenger in methanol gives the n
eutral complex [ReCl2(PPh(3))(N=NC5H4N)(HN=NC5H4N)] (2). The neutral,
six-coordinate complex contains a singly-bent pyridyldiazenido ligand
and a bidentate, organodiazene ligand that is chelated through the pyr
idine nitrogen atom, The IR spectrum displays a series of strong absor
ptions in the 1600-1150 cm(-1) region characteristic of the organohydr
azide ligands. The FAB(+) mass spectrum displays the protonated parent
ion of 733 m/z and the ion [ReCl(PPh(3))(N=NHC5H4N)(HN=NC5H4N)](+) of
697 m/z. The X-ray crystal structure of this complex displays a cis a
rrangement of chloride ligands with the pyridine nitrogen atom of the
organodiazene chelate located in the position trans to the pyridyldiaz
enido ligand. Crystal data for ReCl2PN6C28H26: monoclinic space group
P2(1)/n, a=10.263(2), b=14.938(3), c=19.650(4) Angstrom, beta=97.54(3)
degrees with Z=4 to give V=2995.5(15) Angstrom(3). The coordination ge
ometry is distorted octahedral. The Re-N bond length to the pyridine n
itrogen atom of the organodiazene chelate is 2.147(15) Angstrom, while
the Re-N bond to the diazene-alpha-nitrogen atom is 1.915(21) Angstro
m. The N-N bond length of this ligand is 1.340(26) Angstrom, indicativ
e of multiple bonding within the chelated ligand, The Re-N bond length
of the pyridyldiazenido ligand is 1.778(14) Angstrom, and the N-N bon
d length is 1.212(22) Angstrom, again reflecting the multiple bonding
throughout the singly-bent, organodiazenido unit. The bond angle of th
e Re-N-N linkage is 172.8(13)degrees.