Isolation of dysprosium and yttrium complexes of a three-electron reduction product in the activation of dinitrogen, the (N2)3- radical.
DyI(2) reacts with 2 equiv of KOAr (OAr = OC(6)H(3)(CMe(3))(2)-2,6) under nitrogen to form not only the (N(2))(2-) complex, [(ArO)(2)(THF)(2)Dy](2)(mu-eta(2):eta(2)-N(2)), 1, but also complexes of similar formula with an added potassium ion, [(ArO)(2)(THF)Dy](2)(mu-eta(2):eta(2)-N(2))[K(THF)(6)], 2, and [(ArO)(2)(THF)Dy](2)(mu(3)-eta(2):eta(2):eta(2)-N(2))K(THF), 3. The 1.396(7) and 1.402(7) A N-N bond distances in 2 and 3, respectively, are consistent with an (N(2))(3-) ligand, but the high magnetic moment of 4f(9) Dy(3+) precluded definitive identification. The Y[N(SiMe(3))(2)](3)/K reduction system was used to synthesize yttrium analogues of 2 and 3, {[(Me(3)Si)(2)N](2)(THF)Y}(2)(mu-eta(2):eta(2)-N(2))[K(THF)(6)] and {[(Me(3)Si)(2)N](2)(THF)Y}(2)(mu(3)-eta(2):eta(2):eta(2)-N(2))K, that had similar N-N distances and allowed full characterization. EPR, Raman, and DFT studies are all consistent with the presence of (N(2))(3-) in these complexes. (15)N analogues were also prepared to confirm the spectroscopic assignments. The DFT studies suggest that the unpaired electron is localized primarily in a dinitrogen pi orbital isolated spatially, energetically, and by symmetry from the metal orbitals.
Evans
William J
WJ
Department of Chemistry, University of California, Irvine, California 92697, USA. wevans@uci.edu
Fang
Ming
M
Zucchi
Gaël
G
Furche
Filipp
F
Ziller
Joseph W
JW
Hoekstra
Ryan M
RM
Zink
Jeffrey I
JI
D004419:Dysprosium / Q000737:chemistry*; D004583:Electrons; D005609:Free Radicals / Q000737:chemistry*; D008958:Models, Molecular; D009584:Nitrogen / Q000737:chemistry*; D010084:Oxidation-Reduction; D013057:Spectrum Analysis; D015019:Yttrium / Q000737:chemistry*
D005609:Free Radicals; D004419:Dysprosium; D015019:Yttrium; D009584:Nitrogen