Expanding
Thorium Hydride Chemistry Through Th<sup>2+</sup>, Including the Synthesis
of a Mixed-Valent Th<sup>4+</sup>/Th<sup>3+</sup> Hydride Complex
Ryan R. Langeslay
Megan
E. Fieser
Joseph W. Ziller
Filipp Furche
William J. Evans
10.1021/jacs.5b11508.s003
https://acs.figshare.com/articles/dataset/Expanding_Thorium_Hydride_Chemistry_Through_Th_sup_2_sup_Including_the_Synthesis_of_a_Mixed_Valent_Th_sup_4_sup_Th_sup_3_sup_Hydride_Complex/3114832
The
reactivity of the recently discovered Th<sup>2+</sup> complex
[K(18-crown-6)(THF)<sub>2</sub>][Cp″<sub>3</sub>Th], <b>1</b> [Cp′′ = C<sub>5</sub>H<sub>3</sub>(SiMe<sub>3</sub>)<sub>2</sub>-1,3], with hydrogen reagents has been investigated
and found to provide syntheses of new classes of thorium hydride compounds.
Complex <b>1</b> reacts with [Et<sub>3</sub>NH][BPh<sub>4</sub>] to form the terminal Th<sup>4+</sup> hydride complex Cp″<sub>3</sub>ThH, <b>2</b>, a reaction that formally involves a net
two-electron reduction. Complex <b>1</b> also reacts in the
solid state and in solution with H<sub>2</sub> to form a mixed-valent
bimetallic product, [K(18-crown-6)(Et<sub>2</sub>O)][Cp″<sub>2</sub>ThH<sub>2</sub>]<sub>2</sub>, <b>3</b>, which was analyzed
by X-ray crystallography, electron paramagnetic resonance and optical
spectroscopy, and density functional theory. The existence of <b>3</b>, which formally contains Th<sup>3+</sup> and Th<sup>4+</sup>, suggested that KC<sub>8</sub> could reduce [(C<sub>5</sub>Me<sub>5</sub>)<sub>2</sub>ThH<sub>2</sub>]<sub>2</sub>. In the presence
of 18-crown-6, this reaction forms an analogous mixed-valent product
formulated as [K(18-crown-6)(THF)][(C<sub>5</sub>Me<sub>5</sub>)<sub>2</sub>ThH<sub>2</sub>]<sub>2</sub>, <b>4</b>. A similar complex
with (C<sub>5</sub>Me<sub>4</sub>H)<sup>1–</sup> ligands was
not obtained, but reaction of (C<sub>5</sub>Me<sub>4</sub>H)<sub>3</sub>Th with H<sub>2</sub> in the presence of KC<sub>8</sub> and 2.2.2-cryptand
at −45 °C produced two monometallic hydride products,
namely, (C<sub>5</sub>Me<sub>4</sub>H)<sub>3</sub>ThH, <b>5</b>, and [K(2.2.2-cryptand)]{(C<sub>5</sub>Me<sub>4</sub>H)<sub>2</sub>[η<sup>1</sup>:η<sup>5</sup>-C<sub>5</sub>Me<sub>3</sub>H(CH<sub>2</sub>)]ThH]}, <b>6</b>. Complex <b>6</b> contains
a metalated tetramethylcyclopentadienyl dianion, [C<sub>5</sub>Me<sub>3</sub>H(CH<sub>2</sub>)]<sup>2–</sup>, that binds in a tuck-in
mode.
2016-03-15 12:36:39
5H
thorium hydride compounds
C 5Me
monometallic hydride products
H 2
Complex 1
KC 8
Thorium Hydride Chemistry
C 5Me ligands
metalated tetramethylcyclopentadienyl dianion
3NH