CooperativeB–H Activation: Ligand Diversityin Groups 6 and 8 Transition Metal κ<sup>2</sup>-<i>N,E</i>-Chelated Complexes (E = S or Se)
The synthesis, structure, and reactivity of the <i>N</i>-heterocyclic carbene (NHC)-supported κ<sup>2</sup>-<i>N,S</i>-chelated ruthenium complex [(IMe)(PPh<sub>3</sub>)Ru{κ<sup>2</sup>-<i>N,S</i>-(mbz)}<sub>2</sub>] (IMe = 1,3-dimethylimidazol-2-ylidene, mbz = 2-mercaptobenzothiazolyl (NC<sub>7</sub>H<sub>4</sub>S<sub>2</sub>)), <b>2</b> has been established. Complex <b>2</b> is generated from the reaction of [Ru(PPh<sub>3</sub>)<sub>2</sub>Cl<sub>2</sub>], <b>1</b> with IMe followed by the addition of [(mbz)K]. The room-temperature reaction of <b>2</b> with [BH<sub>3</sub>·THF] led to the formation of the dihydridoborate complex, [(Ph<sub>3</sub>P)Ru{κ<sup>3</sup>-<i>H</i>,<i>S</i>,<i>S</i>′-(NH<sub>2</sub>BSBH<sub>2</sub>N)(S<sub>2</sub>C<sub>7</sub>H<sub>4</sub>)<sub>2</sub>}], <b>3</b>. Further, the synthesis and structure of Cp*-supported κ<sup>2</sup>-<i>N,S</i>-chelated tungsten complexes, [Cp*W(CO)<sub>2</sub>{κ<sup>2</sup>-<i>N,S</i>-(NC<sub>7</sub>H<sub>4</sub>S<sub>2</sub>)}], <b>5</b> and [Cp*W(CO)<sub>2</sub>{κ<sup>2</sup>-<i>N,S</i>-(NC<sub>7</sub>H<sub>4</sub>S<sub>2</sub>)}{κ<sup>2</sup>-<i>N,S</i>-(N(CH<sub>3</sub>)C<sub>5</sub>H<sub>4</sub>S)}], <b>6</b>, generated from the reaction of [Cp*W(CO)<sub>3</sub>Me], <b>4</b> and [Na(H<sub>3</sub>B-NC<sub>7</sub>H<sub>4</sub>S<sub>2</sub>)] have been described. In a similar fashion, pyridine-2-thiolato/selenolato ligand-supported Cp*-based κ<sup>2</sup>-<i>N,E</i>-chelated (E = S and Se) tungsten complexes, [Cp*W(CO)<sub>2</sub>{κ<sup>2</sup>-<i>N,E</i>-(NC<sub>5</sub>H<sub>4</sub>E)}] (<b>7a</b>: E = S (pyridine-2-thiolato), <b>7b</b>: E = Se (pyridine-2-selenolato)), have been isolated from the reaction of [Cp*W(CO)<sub>3</sub>Me], <b>4</b> and [Na(H<sub>3</sub>B-NC<sub>5</sub>H<sub>4</sub>E)] ligands. The reaction of bulky borane Ar<sup>F</sup>BH<sub>2</sub> (Ar<sup>F</sup> = 3,5-bistrifluoromethylbenzyl) with <b>5</b> led to the isolation of a borate species, [Cp*W(CO)<sub>2</sub>{κ<sup>2</sup>-<i>S,H</i>-(H<sub>2</sub>Ar<sup>F</sup>B-NC<sub>7</sub>H<sub>4</sub>S<sub>2</sub>)}], <b>10</b>. The complex [Cp*Mo(CO)<sub>2</sub>{κ<sup>2</sup>-<i>N,Se</i>-(NC<sub>5</sub>H<sub>4</sub>Se)}], <b>9</b> generated from the salt elimination reaction of [Cp*Mo(CO)<sub>3</sub>Cl], <b>8</b> and [K(NC<sub>5</sub>H<sub>4</sub>Se)] reacts with [BH<sub>3</sub>·THF] to yield the borate complex [Cp*Mo(CO)<sub>2</sub>{κ<sup>2</sup>-<i>Se,H</i>-(H<sub>3</sub>B-NC<sub>5</sub>H<sub>4</sub>Se)}], <b>11</b>. To investigate the effect of the ligand diversities on the reactivity of all of the κ<sup>2</sup>-<i>N,E</i>-chelated complexes, density functional theory (DFT)-based calculations were performed.
Publication Details
- Journal
- Figshare
- Published
- 2025-02-04
- DOI
- https://doi.org/10.1021/acs.inorgchem.4c03546.s001
- Primary Topic
- N-Heterocyclic Carbenes in Organic and Inorganic Chemistry
- Type
- article
- Field-Weighted Citation Impact
- 0.00