Resonance Raman and X-ray Crystallographic Studies of Intertriad Metal-Metal Bonds. 2. WRu and MoOs Porphyrin Dimers.
Solution ((1)H NMR, Evans method magnetic susceptibility, resonance Raman) and X-ray crystallographic spectroscopic studies of intertriad heterodimeric [(OEP)MoOs(OEP)] (3), [(OEP)WRu(OEP)] (4), [(OEP)MoOs(TPP)]PF(6) (5(+)), and [(OEP)WRu(TPP)]PF(6) (6(+)) metalloporphyrins are reported (OEP = 2,3,7,8,12,13,17,18-octaethylporphyrinato; TPP = 5,10,15,20-tetraphenylporphyrinato). Evans method magnetic susceptibility data indicate that 3 and 4 contain two unpaired electrons in the ground electronic configuration. Resonance Raman spectra of 3, 4, 5(+), and 6(+) suggest that WRu bonds are 5-10% stronger than corresponding MoOs species. Structural characterization of 5(+) and 6(+) demonstrates metal-metal bond lengths of 2.30 (WRu) and 2.24 (MoOs) Å, respectively. The possibility of a special stability associated with polar heterometallic multiple bonds is discussed.
Collman
James P.
JP
Department of Chemistry, Stanford University, Stanford, California 94305, and Los Alamos National Laboratory, Los Alamos, New Mexico 87545.
Harford
S. T.
ST
Franzen
Stefan
S
Shreve
Andrew P.
AP
Woodruff
William H.
WH