Expanding Dinitrogen Reduction Chemistry to Trivalent
Lanthanides via the LnZ<sub>3</sub>/Alkali Metal Reduction System:
Evaluation of the Generality of Forming Ln<sub>2</sub>(μ<i>-</i>η<i><sup>2</sup></i><sup></sup><i>:</i>η<i><sup>2</sup></i><sup></sup>-N<sub>2</sub>)
Complexes via LnZ<sub>3</sub>/K
William J. Evans
David S. Lee
Daniel B. Rego
Jeremy M. Perotti
Stosh A. Kozimor
Ericka K. Moore
Joseph W. Ziller
10.1021/ja046047s.s009
https://acs.figshare.com/articles/dataset/Expanding_Dinitrogen_Reduction_Chemistry_to_Trivalent_Lanthanides_via_the_LnZ_sub_3_sub_Alkali_Metal_Reduction_System_Evaluation_of_the_Generality_of_Forming_Ln_sub_2_sub_i_i_i_sup_2_sup_i_sup_sup_i_i_i_sup_2_sup_i_sup_sup_N_sub_2_sub_Complexes_via_LnZ_su/3316735
The Ln[N(SiMe<sub>3</sub>)<sub>2</sub>]<sub>3</sub>/K dinitrogen reduction system, which mimicks the reactions of the highly
reducing divalent ions Tm(II), Dy(II), and Nd(II), has been explored with the entire lanthanide series and
uranium to examine its generality and to correlate the observed reactivity with accessibility of divalent
oxidation states. The Ln[N(SiMe<sub>3</sub>)<sub>2</sub>]<sub>3</sub>/K reduction of dinitrogen provides access from readily available starting
materials to the formerly rare class of M<sub>2</sub>(μ<i>-</i>η<i><sup>2</sup></i><sup></sup><i>:</i>η<i><sup>2</sup></i><sup></sup>-N<sub>2</sub>) complexes, {[(Me<sub>3</sub>Si)<sub>2</sub>N]<sub>2</sub>(THF)Ln}<sub>2</sub>(μ<i>-</i>η<i><sup>2</sup></i><sup></sup><i>:</i>η<i><sup>2</sup></i><sup></sup>-N<sub>2</sub>), <b>1</b>,
that had previously been made only from TmI<sub>2</sub>, DyI<sub>2</sub>, and NdI<sub>2</sub> in the presence of KN(SiMe<sub>3</sub>)<sub>2</sub>. This LnZ<sub>3</sub>/alkali metal reduction system provides crystallographically characterizable examples of <b>1</b> for Nd, Gd, Tb,
Dy, Ho, Er, Y, Tm, and Lu. Sodium can be used as the alkali metal as well as potassium. These compounds
have NN distances in the 1.258(3) to 1.318(5) Å range consistent with formation of an (NN)<sup>2-</sup> moiety.
Isolation of <b>1</b> with this selection of metals demonstrates that the Ln[N(SiMe<sub>3</sub>)<sub>2</sub>]<sub>3</sub>/alkali metal reaction can
mimic divalent lanthanide reduction chemistry with metals that have calculated Ln(III)/Ln(II) reduction
potentials ranging from −2.3 to −3.9 V vs NHE. In the case of Ln = Sm, which has an analogous Ln(III)/Ln(II) potential of −1.55 V, reduction to the stable divalent tris(amide) complex, K{Sm[N(SiMe<sub>3</sub>)<sub>2</sub>]<sub>3</sub>}, is
observed instead of dinitrogen reduction. When the metal is La, Ce, Pr, or U, the first crystallographically
characterized examples of the tetrakis[bis(trimethylsilyl)amide] anions, {M[N(SiMe<sub>3</sub>)<sub>2</sub>]<sub>4</sub>}<sup>-</sup>, are isolated as
THF-solvated potassium or sodium salts. The implications of the LnZ<sub>3</sub>/alkali metal reduction chemistry on
the mechanism of dinitrogen reduction and on reductive lanthanide chemistry in general are discussed.
2004-11-10 00:00:00
reductive lanthanide chemistry
THF
dinitrogen reduction
alkali
divalent oxidation states
divalent lanthanide reduction chemistry
N 2
Dinitrogen Reduction Chemistry
NN
η 2
LnZ
KN
Ln
NHE
crystallographically characterizable examples