10.1021/om9509397.s001 Victorio Cadierno Victorio Cadierno M. Pilar Gamasa M. Pilar Gamasa José Gimeno José Gimeno Mercedes González-Cueva Mercedes González-Cueva Elena Lastra Elena Lastra Javier Borge Javier Borge Santiago García-Granda Santiago García-Granda Enrique Pérez-Carreño Enrique Pérez-Carreño Activation of 2-Propyn-1-ol Derivatives by Indenylruthenium(II) and -osmium(II) Complexes:  X-ray Crystal Structures of the Allenylidene Complexes [M(CCCPh<sub>2</sub>)(η<sup>5</sup>-C<sub>9</sub>H<sub>7</sub>)(PPh<sub>3</sub>)<sub>2</sub>][PF<sub>6</sub>]·CH<sub>2</sub>Cl<sub>2</sub> (M = Ru, Os) and EHMO Calculations American Chemical Society 1996 Ru PPh 3 HC dppm dppe refluxing methanol RuCl L 2 OH NaPF 6 C 9 H 7 CH potassium carbonate yields allenylidene complexes EHMO 2 Ph Extended H ückel 1996-04-16 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Activation_of_2-Propyn-1-ol_Derivatives_by_Indenylruthenium_II_and_-osmium_II_Complexes_X-ray_Crystal_Structures_of_the_Allenylidene_Complexes_M_C_C_CPh_sub_2_sub_sup_5_sup_-C_sub_9_sub_H_sub_7_sub_PPh_sub_3_sub_sub_2_sub_PF_sub_6_sub_CH_sub_2_sub_Cl_sub_/3776964 The allenylidene complexes [M(CCCR<sub>2</sub>)(η<sup>5</sup>-C<sub>9</sub>H<sub>7</sub>)L<sub>2</sub>][PF<sub>6</sub>] (M = Ru, L = PPh<sub>3</sub>, L<sub>2</sub> = 1,2-bis(diphenylphosphino)ethane (dppe), bis(diphenylphosphino)methane (dppm), R<sub>2</sub> = 2 Ph (<b>1a−c</b>), C<sub>12</sub>H<sub>8</sub> (2,2‘-biphenyldiyl) (<b>2a−c</b>); M = Os, L = PPh<sub>3</sub>, R<sub>2</sub> = 2Ph (<b>3</b>), C<sub>12</sub>H<sub>8</sub> (<b>4</b>)) have been prepared by reaction of the complexes [MCl(η<sup>5</sup>-C<sub>9</sub>H<sub>7</sub>)L<sub>2</sub>] with HC⋮CC(OH)R<sub>2</sub> and NaPF<sub>6</sub> in refluxing methanol. The crystal structures of [M(CCCPh<sub>2</sub>)(η<sup>5</sup>-C<sub>9</sub>H<sub>7</sub>)(PPh<sub>3</sub>)<sub>2</sub>][PF<sub>6</sub>]·CH<sub>2</sub>Cl<sub>2</sub> (M = Ru (<b>1a</b>), Os (<b>3</b>)) were determined by X-ray diffraction methods. In the structures the MCCC chains are nearly linear (M−C(1)−C(2) = 168.5(5)° (<b>1a</b>) and 169.3(4)° (<b>3</b>); C(1)−C(2)−C(3) = 168.2(7)° (<b>1a</b>) and 168.0(5)° (<b>3</b>)) with MC(1) distances of 1.878(5) Å (<b>1a</b>) and 1.895(4) Å (<b>3</b>). The indenyl ligand is η<sup>5</sup>-bonded to the metal with the benzo ring orientated “cis” with respect to the allenylidene group. Extended Hückel molecular orbital calculations have been used to rationalize the preferred “cis” orientation. The reaction of [RuCl(η<sup>5</sup>-C<sub>9</sub>H<sub>7</sub>)L<sub>2</sub>] (L = PPh<sub>3</sub>, L<sub>2</sub> = dppe, dppm) with HC⋮CCMe(OH)Ph and NaPF<sub>6</sub> in refluxing methanol leads to the formation of the allenylidene complexes [Ru{CCC(Me)Ph}(η<sup>5</sup>-C<sub>9</sub>H<sub>7</sub>)L<sub>2</sub>][PF<sub>6</sub>] (<b>6a−c</b>) along with the vinylvinylidene isomers [Ru{CC(H)C(Ph)CH<sub>2</sub>}(η<sup>5</sup>-C<sub>9</sub>H<sub>7</sub>)L<sub>2</sub>][PF<sub>6</sub>] (L = PPh<sub>3</sub> (<b>5a</b>), L<sub>2</sub> = dppe (<b>5b</b>), dppm (<b>5c</b>)). Only complex <b>6a</b> could be isolated by chromatography (SiO<sub>2</sub>) from these mixtures along with complex <b>7a</b> obtained from the deprotonation of the vinylvinylidene complex <b>5a</b>. The treatment of these reaction mixtures with potassium carbonate yields the neutral σ-enynyl derivatives [Ru{C⋮CC(Ph)CH<sub>2</sub>}(η<sup>5</sup>-C<sub>9</sub>H<sub>7</sub>)L<sub>2</sub>] (<b>7a−c</b>). The monosubstituted allenylidene complex [Ru{CCC(H)Ph}(η<sup>5</sup>-C<sub>9</sub>H<sub>7</sub>)(PPh<sub>3</sub>)<sub>2</sub>][PF<sub>6</sub>] (<b>9</b>) has been prepared by the reaction of [RuCl(η<sup>5</sup>-C<sub>9</sub>H<sub>7</sub>)(PPh<sub>3</sub>)<sub>2</sub>] with HC⋮CCH(OH)Ph and NaPF<sub>6</sub> in methanol. Under similar reaction conditions [RuCl(η<sup>5</sup>-C<sub>9</sub>H<sub>7</sub>)L<sub>2</sub>] reacts with HC⋮CCH(OH)R and NaPF<sub>6</sub> to afford the alkenylmethoxycarbene derivatives [Ru{C(OMe)C(H)CH(R)}(η<sup>5</sup>-C<sub>9</sub>H<sub>7</sub>)L<sub>2</sub>][PF<sub>6</sub>] (L<sub>2</sub> = dppe, R = Ph (<b>11b</b>); L<sub>2</sub> = dppm, R = Ph (<b>11c</b>), H (<b>13</b>)). [RuCl(η<sup>5</sup>-C<sub>9</sub>H<sub>7</sub>)(PPh<sub>3</sub>)<sub>2</sub>] also reacts with HC⋮CC(OH)H<sub>2</sub> to give the hydroxyvinylidene complex [Ru{CCH(CH<sub>2</sub>OH)}(η<sup>5</sup>-C<sub>9</sub>H<sub>7</sub>)(PPh<sub>3</sub>)<sub>2</sub>][PF<sub>6</sub>] (<b>12</b>), which is stable toward the dehydration process.