Synthesis and Characterization of Hydride-Alkynyl, Allenylidene, Carbyne, and Functionalized-Alkynyl Complexes Containing the [Os(<
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- 作者：Miguel Baya ; Pascale Crochet ; Miguel A. Esteruelas ; Enrique Gutié ; rrez-Puebla ; Ana M. Ló ; pez ; Javier Modrego ; Enrique Oñ ; ate ; and Noelia Vela
- 刊名：Organometallics
- 出版年：2000
- 出版时间：June 26, 2000
- 年：2000
- 卷：19
- 期：13
- 页码：2585 - 2596
- 全文大小：300K
- 年卷期：v.19,no.13(June 26, 2000)
- ISSN：1520-6041
文摘
Complex Os(
5-C5H5)Cl(PiPr3)2 (1) reacts with equimolecular mixtures of TlPF6 and alkynessuch as phenylacetylene and cyclohexylacetylene to give [OsH(5-C5H5)(C
CR)(PiPr3)2]PF6(R = Ph (2), Cy (3)). The structure of 2 in the solid state has been determined by X-raydiffraction analysis. The distribution of ligands around the metallic center can be describedas a four-legged piano-stool geometry with the hydride and alkynyl ligands mutually transoid.The reaction of 1 with 2-phenyl-3-butyn-2-ol and TlPF6 leads to [OsH(5-C5H5){CCC(OH)MePh}(PiPr3)2]PF6 (4), which evolves into the hydride-enynyl complex [OsH(5-C5H5){CCC(Ph)=CH2}(PiPr3)2]PF6 (5) in solution of chloroform. Treatment of 1 with 1,1-diphenyl-2-propyn-1-ol and TlPF6 affords [OsH(5-C5H5){CCC(OH)Ph2}(PiPr3)2]PF6 (6), which reactswith KOH in methanol to give the neutral compound Os(5-C5H5){CCC(OH)Ph2}(PiPr3)2(7) by extraction of the hydride ligand. The addition of 1 equiv of HPF6 to the solutions of7 leads to the allenylidene, [Os(5-C5H5)(C=C=CPh2)(PiPr3)2]PF6 (8), which affords thedicationic carbyne derivative [Os(5-C5H5)(CCH=CPh2)(PiPr3)2](PF6)2 (9) by reaction withHPF6. The structure of 9 in the solid state has been also determined by X-ray diffractionanalysis. In this case, the geometry around the osmium center is close to octahedral withthe triisopropylphosphine ligands mutually cis disposed (P-Os-P = 105.12(8)
). Complex8 also reacts with nucleophilic reagents; the reaction with CH3Li gives Os(5-C5H5){CCC(CH3)Ph2}(PiPr3)2 (10), whereas the reactions with acetone and methanol solutions of KOHafford Os(5-C5H5){CCC[CH2C(O)CH3]Ph2}(PiPr3)2 (11) and Os(5-C5H5){CCC(OCH3)Ph2}(PiPr3)2 (12), respectively. To understand the chemical behavior of 8, EHT-MO calculationson the model compounds Os(5-C5H5)Cl(C=C=CH2)(PH3) (13) and [Os(5-C5H5)(C=C=CH2)L(PH3)]+ (L = PH3 (14), CO (15)) have been also carried out. The results suggest that thebehavior of 8 as nucleophile is a consequence of the high electron density of the allenylideneligand, while the behavior as 
-electrophile is due to its cationic nature. In addition, wehave determined by ab initio calculations the energies of stabilization by protonation of 13-15 with a naked proton. In the three cases the formation of the corresponding carbynederivatives [Os(5-C5H5)Cl(CCH=CH2)(PH3)]+ (16; 267 kcal·mol-1), [Os(5-C5H5)(CCH=CH2)(PH3)2]2+ (17; 180 kcal·mol-1), and [Os(5-C5H5)(CCH=CH2)(CO)(PH3)]2+ (18; 157 kcal·mol-1)involves a stabilization of the system.
5-C5H5)Cl(PiPr3)2 (1) reacts with equimolecular mixtures of TlPF6 and alkynessuch as phenylacetylene and cyclohexylacetylene to give [OsH(5-C5H5)(CCR)(PiPr3)2]PF6(R = Ph (2), Cy (3)). The structure of 2 in the solid state has been determined by X-raydiffraction analysis. The distribution of ligands around the metallic center can be describedas a four-legged piano-stool geometry with the hydride and alkynyl ligands mutually transoid.The reaction of 1 with 2-phenyl-3-butyn-2-ol and TlPF6 leads to [OsH(5-C5H5){CCC(OH)MePh}(PiPr3)2]PF6 (4), which evolves into the hydride-enynyl complex [OsH(5-C5H5){CCC(Ph)=CH2}(PiPr3)2]PF6 (5) in solution of chloroform. Treatment of 1 with 1,1-diphenyl-2-propyn-1-ol and TlPF6 affords [OsH(5-C5H5){CCC(OH)Ph2}(PiPr3)2]PF6 (6), which reactswith KOH in methanol to give the neutral compound Os(5-C5H5){CCC(OH)Ph2}(PiPr3)2(7) by extraction of the hydride ligand. The addition of 1 equiv of HPF6 to the solutions of7 leads to the allenylidene, [Os(5-C5H5)(C=C=CPh2)(PiPr3)2]PF6 (8), which affords thedicationic carbyne derivative [Os(5-C5H5)(CCH=CPh2)(PiPr3)2](PF6)2 (9) by reaction withHPF6. The structure of 9 in the solid state has been also determined by X-ray diffractionanalysis. In this case, the geometry around the osmium center is close to octahedral withthe triisopropylphosphine ligands mutually cis disposed (P-Os-P = 105.12(8)). Complex8 also reacts with nucleophilic reagents; the reaction with CH3Li gives Os(5-C5H5){CCC(CH3)Ph2}(PiPr3)2 (10), whereas the reactions with acetone and methanol solutions of KOHafford Os(5-C5H5){CCC[CH2C(O)CH3]Ph2}(PiPr3)2 (11) and Os(5-C5H5){CCC(OCH3)Ph2}(PiPr3)2 (12), respectively. To understand the chemical behavior of 8, EHT-MO calculationson the model compounds Os(5-C5H5)Cl(C=C=CH2)(PH3) (13) and [Os(5-C5H5)(C=C=CH2)L(PH3)]+ (L = PH3 (14), CO (15)) have been also carried out. The results suggest that thebehavior of 8 as nucleophile is a consequence of the high electron density of the allenylideneligand, while the behavior as -electrophile is due to its cationic nature. In addition, wehave determined by ab initio calculations the energies of stabilization by protonation of 13-15 with a naked proton. In the three cases the formation of the corresponding carbynederivatives [Os(5-C5H5)Cl(CCH=CH2)(PH3)]+ (16; 267 kcal·mol-1), [Os(5-C5H5)(CCH=CH2)(PH3)2]2+ (17; 180 kcal·mol-1), and [Os(5-C5H5)(CCH=CH2)(CO)(PH3)]2+ (18; 157 kcal·mol-1)involves a stabilization of the system.