Synthesis, Structure,
and Reactivity of a Thorium Metallocene Containing a 2,2′-Bipyridyl
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Abstract
The reduction of [η<sup>5</sup>-1,2,4-(Me<sub>3</sub>C)<sub>3</sub>C<sub>5</sub>H<sub>2</sub>]<sub>2</sub>ThCl<sub>2</sub> (<b>1</b>) with potassium graphite in the presence of 2,2′-bipyridine
gives the purple thorium bipy metallocene [η<sup>5</sup>-1,2,4-(Me<sub>3</sub>C)<sub>3</sub>C<sub>5</sub>H<sub>2</sub>]<sub>2</sub>Th(bipy)
(<b>2</b>) in good yield. Complex <b>2</b> has been characterized
by various spectroscopic techniques, elemental analysis, and single-crystal
X-ray diffraction. Complex <b>2</b> is a good synthon for low-valent
thorium, as shown by the reactivity with silver halides, trityl chloride,
pyridine-<i>N</i>-oxide, RN<sub>3</sub>, 9-diazofluorene,
and diphenyl diselenide, yielding the halide metallocenes [η<sup>5</sup>-1,2,4-(Me<sub>3</sub>C)<sub>3</sub>C<sub>5</sub>H<sub>2</sub>]<sub>2</sub>ThX<sub>2</sub> (X = Cl (<b>1</b>), F (<b>3</b>), Br (<b>4</b>)), oxo metallocene [η<sup>5</sup>-1,2,4-(Me<sub>3</sub>C)<sub>3</sub>C<sub>5</sub>H<sub>2</sub>]<sub>2</sub>ThO(py)
(<b>5</b>), imido metallocenes [η<sup>5</sup>-1,2,4-(Me<sub>3</sub>C)<sub>3</sub>C<sub>5</sub>H<sub>2</sub>]<sub>2</sub>ThNR
(R = <i>p</i>-tolyl (<b>6</b>), Ph<sub>3</sub>C (<b>7</b>), Me<sub>3</sub>Si (<b>8</b>), (9-C<sub>13</sub>H<sub>8</sub>)N (<b>9</b>)), and selenido complex [η<sup>5</sup>-1,2,4-(Me<sub>3</sub>C)<sub>3</sub>C<sub>5</sub>H<sub>2</sub>]Th(SePh)<sub>3</sub>(bipy) (<b>10a</b>), in quantitative conversions