STRUCTURE OF C5H5)(2)RU2FE2(CO)(8)(MU(2)-CO)(MU(4)-ETA(6)-C6H6) - AN UNUSUAL MIXED-METAL COMPOUND CONTAINING A BRIDGING DIALLYL LIGAND DERIVED BY UNSYMMETRICAL COUPLING OF 2 ALLENYL GROUPS
Mr. Churchill et al., STRUCTURE OF C5H5)(2)RU2FE2(CO)(8)(MU(2)-CO)(MU(4)-ETA(6)-C6H6) - AN UNUSUAL MIXED-METAL COMPOUND CONTAINING A BRIDGING DIALLYL LIGAND DERIVED BY UNSYMMETRICAL COUPLING OF 2 ALLENYL GROUPS, Journal of organometallic chemistry, 512(1-2), 1996, pp. 189-196
The heteronuclear compound C5H5)(2)Ru2Fe2(CO)(8)(mu(2)-CO)(mu(4)-eta(6
)-C6H6) (1), Obtained by reaction of (eta(5)-C5H5)(CO)(2)RuCH=C=CH2 wi
th Fe-2(CO)(9), displays unusually complex H-1 and C-13 NMR spectra, A
ll nine CO ligands, as well as all six carbon and hydrogen atoms of C6
H6, afford separate resonance signals. The structure of 1 was determin
ed by X-ray diffraction techniques. The complex crystallizes from hexa
ne (as a 3.1 cluster:solvate complex) in the centrosymmetric triclinic
space group P (1) over bar with a = 7.852(1) Angstrom, b = 23.487(5)
Angstrom, c = 24.144(4) Angstrom, alpha = 74.47(2)degrees, beta = 84.7
9(1)degrees, gamma = 86.69(1)degrees, V = 4269.8(14) Angstrom(3). The
unit cell contains six polynuclear Ru2Fe2-containing molecules and two
molecules of hexane. X-ray diffraction data (Mo K alpha, 2 theta = 7.
0-40.0 degrees) were collected with a Siemens R3m/V diffractometer and
the structure was refined to R = 6.56% for all 7987 independent refle
ctions (R = 2.90% for those 4844 reflections with \F-o\ > 6 sigma(\F-o
\)). The organometallic molecule is based upon an unusual CH-C(CH2)-C
H-C-CH2 fragment, which is derived from a beta-gamma coupling of two
allenyl moieties and which forms pi-allyl linkages to the two iron ato
ms and sigma-bonds (via the starred carbon atoms) to (eta(5)-C5H5)Ru m
oieties. The metal atoms are arranged as a linear Ru(1)-Fe(2)-Fe(3) sy
stem and a lone Ru(4) atom. Dimensions in the three independent molecu
les are internally consistent, with carbonyl-bridged Ru(1)-Fe(2) dista
nces of 2.687(1), 2.679(1) and 2.687(1) Angstrom and Fe(2)-Fe(3) dista
nces of 2.895(2), 2.871(2) and 2.906(2) Angstrom.