47-electron organometallic clusters derived by chemical and electrochemical oxidation of trihydrido(alkylidyne)triruthenium and -triosmium clusters. Ligand additivity in metal clusters

William G. Feighery; Huirong Yao; Anthony F. Hollenkamp; Robert D. Allendoerfer; Jerome B. Keister

doi:10.1021/om970769t

47-electron organometallic clusters derived by chemical and electrochemical oxidation of trihydrido(alkylidyne)triruthenium and -triosmium clusters. Ligand additivity in metal clusters

William G. Feighery
, Huirong Yao
, Anthony F. Hollenkamp
, Robert D. Allendoerfer
, Jerome B. Keister

Chemistry

University at Buffalo

SUNY Buffalo
Indiana University South Bend
CSIRO

Research output: Contribution to journal › Article › peer-review

18 Scopus citations

Abstract

Cyclic voltammograms for H₃Ru₃(μ₃-CX)(CO)_9-nL_n (X = OMe, SEt, Me, Et, Ph, NMeBz, Br; L = PR₃, AsPh₃, SbPh₃; n = 2, 3), H₃Ru₃(μ₃-COMe)(CO)₆(PPh ₃)₂(L) (L = P(OMe)₃, CNCH₂-Ph), and H₃Os₃(μ₃-COMe)(CO)₇(PPh ₃)₂ each display a quasi-reversible to reversible, one-electron oxidation followed by an irreversible to quasi-reversible, one-electron oxidation. The ligand and substituent effects upon the oxidation potential are analyzed as an example of ligand additivity in a cluster system; the oxidation potential of the alkylidyne cluster core is as sensitive to π-donor substituent effects as are aromatic π complexes such as CpFe-(C₅H₄X) to substituents on the rings, and the dependence of the oxidation potential of the cluster upon ligand substitution on any given Ru atom is 37% of that expected for the oxidation of a monometallic complex. Reactions with 1 equiv of Ag⁺ or ferricenium give the 47-electron cations [H₃Ru₃(CX)(CO)₆L₃]¹⁺ (X = OMe; L₃ = (PPh₃)₂;Ĺ Ĺ = CO, PPh₃, P(OMe)₃, CNCH₂Ph; X = Ph, NMeBz, SEt, L = PPh₃), characterized by EPR spectroscopy; the equilibrium between isomers H₃Ru₃(COMe)(CO)₆(ax-PPh₃) ₂(ax- and eq-PPh₃)^0/1+ (ax = axial coordination, eq = equatorial coordination) favors the axial coordination for the 48-electron cluster (eq/ax = 0.15) and equatorial coordination for the 47-electron species (eq/ax = 6.4). The rate constant for ax-eq isomerization for the 47-electron species (6.5 s^-1) is 4 orders of magnitude greater than that for the 48-electron species (2 × 10^-4 s^-1). The 47-electron clusters have lifetimes which are correlated with the oxidation potentials of the precursors, ranging from seconds to many hours at room temperature. Slow decomposition of [H₃Ru₃-(COMe)(CO)₆L₃]¹⁺ in the absence of added CO forms the new 46-electron clusters [H₃Ru₃-(CO)₇L₃]¹⁺ (L = PPh₃, AsPh₃). [H₃Ru₃(COMe)(CO)₆(PPh₃) ₃]¹⁺ does not react with CCl₄ but does react with Lewis bases such as CO and acetonitrile. Disproportionation occurs with acetonitrile, chloride, and pyridine; the CO products are [HRu₃(CO)₉(PPh₃)₃]¹⁺, [MePPh₃]¹⁺, and H₃Ru₃(COMe)(CO)_9-n(PPH₃)_n (n = 1, 2).

Original language	English
Pages (from-to)	872-886
Number of pages	15
Journal	Organometallics
Volume	17
Issue number	5
DOIs	https://doi.org/10.1021/om970769t
State	Published - Mar 2 1998

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@article{04f59704ac3d47d18c78052d54a5f07e,

title = "47-electron organometallic clusters derived by chemical and electrochemical oxidation of trihydrido(alkylidyne)triruthenium and -triosmium clusters. Ligand additivity in metal clusters",

abstract = "Cyclic voltammograms for H3Ru3(μ3-CX)(CO)9-nLn (X = OMe, SEt, Me, Et, Ph, NMeBz, Br; L = PR3, AsPh3, SbPh3; n = 2, 3), H3Ru3(μ3-COMe)(CO)6(PPh 3)2(L) (L = P(OMe)3, CNCH2-Ph), and H3Os3(μ3-COMe)(CO)7(PPh 3)2 each display a quasi-reversible to reversible, one-electron oxidation followed by an irreversible to quasi-reversible, one-electron oxidation. The ligand and substituent effects upon the oxidation potential are analyzed as an example of ligand additivity in a cluster system; the oxidation potential of the alkylidyne cluster core is as sensitive to π-donor substituent effects as are aromatic π complexes such as CpFe-(C5H4X) to substituents on the rings, and the dependence of the oxidation potential of the cluster upon ligand substitution on any given Ru atom is 37\% of that expected for the oxidation of a monometallic complex. Reactions with 1 equiv of Ag+ or ferricenium give the 47-electron cations [H3Ru3(CX)(CO)6L3]1+ (X = OMe; L3 = (PPh3)2;{\'L} {\'L} = CO, PPh3, P(OMe)3, CNCH2Ph; X = Ph, NMeBz, SEt, L = PPh3), characterized by EPR spectroscopy; the equilibrium between isomers H3Ru3(COMe)(CO)6(ax-PPh3) 2(ax- and eq-PPh3)0/1+ (ax = axial coordination, eq = equatorial coordination) favors the axial coordination for the 48-electron cluster (eq/ax = 0.15) and equatorial coordination for the 47-electron species (eq/ax = 6.4). The rate constant for ax-eq isomerization for the 47-electron species (6.5 s-1) is 4 orders of magnitude greater than that for the 48-electron species (2 × 10-4 s-1). The 47-electron clusters have lifetimes which are correlated with the oxidation potentials of the precursors, ranging from seconds to many hours at room temperature. Slow decomposition of [H3Ru3-(COMe)(CO)6L3]1+ in the absence of added CO forms the new 46-electron clusters [H3Ru3-(CO)7L3]1+ (L = PPh3, AsPh3). [H3Ru3(COMe)(CO)6(PPh3) 3]1+ does not react with CCl4 but does react with Lewis bases such as CO and acetonitrile. Disproportionation occurs with acetonitrile, chloride, and pyridine; the CO products are [HRu3(CO)9(PPh3)3]1+, [MePPh3]1+, and H3Ru3(COMe)(CO)9-n(PPH3)n (n = 1, 2).",

author = "Feighery, \{William G.\} and Huirong Yao and Hollenkamp, \{Anthony F.\} and Allendoerfer, \{Robert D.\} and Keister, \{Jerome B.\}",

year = "1998",

month = mar,

day = "2",

doi = "10.1021/om970769t",

language = "English",

volume = "17",

pages = "872--886",

journal = "Organometallics",

issn = "0276-7333",

publisher = "American Chemical Society",

number = "5",

}

47-electron organometallic clusters derived by chemical and electrochemical oxidation of trihydrido(alkylidyne)triruthenium and -triosmium clusters. Ligand additivity in metal clusters. / Feighery, William G.; Yao, Huirong; Hollenkamp, Anthony F. et al.
In: Organometallics, Vol. 17, No. 5, 02.03.1998, p. 872-886.

Research output: Contribution to journal › Article › peer-review

TY - JOUR

T1 - 47-electron organometallic clusters derived by chemical and electrochemical oxidation of trihydrido(alkylidyne)triruthenium and -triosmium clusters. Ligand additivity in metal clusters

AU - Feighery, William G.

AU - Yao, Huirong

AU - Hollenkamp, Anthony F.

AU - Allendoerfer, Robert D.

AU - Keister, Jerome B.

PY - 1998/3/2

Y1 - 1998/3/2

N2 - Cyclic voltammograms for H3Ru3(μ3-CX)(CO)9-nLn (X = OMe, SEt, Me, Et, Ph, NMeBz, Br; L = PR3, AsPh3, SbPh3; n = 2, 3), H3Ru3(μ3-COMe)(CO)6(PPh 3)2(L) (L = P(OMe)3, CNCH2-Ph), and H3Os3(μ3-COMe)(CO)7(PPh 3)2 each display a quasi-reversible to reversible, one-electron oxidation followed by an irreversible to quasi-reversible, one-electron oxidation. The ligand and substituent effects upon the oxidation potential are analyzed as an example of ligand additivity in a cluster system; the oxidation potential of the alkylidyne cluster core is as sensitive to π-donor substituent effects as are aromatic π complexes such as CpFe-(C5H4X) to substituents on the rings, and the dependence of the oxidation potential of the cluster upon ligand substitution on any given Ru atom is 37% of that expected for the oxidation of a monometallic complex. Reactions with 1 equiv of Ag+ or ferricenium give the 47-electron cations [H3Ru3(CX)(CO)6L3]1+ (X = OMe; L3 = (PPh3)2;Ĺ Ĺ = CO, PPh3, P(OMe)3, CNCH2Ph; X = Ph, NMeBz, SEt, L = PPh3), characterized by EPR spectroscopy; the equilibrium between isomers H3Ru3(COMe)(CO)6(ax-PPh3) 2(ax- and eq-PPh3)0/1+ (ax = axial coordination, eq = equatorial coordination) favors the axial coordination for the 48-electron cluster (eq/ax = 0.15) and equatorial coordination for the 47-electron species (eq/ax = 6.4). The rate constant for ax-eq isomerization for the 47-electron species (6.5 s-1) is 4 orders of magnitude greater than that for the 48-electron species (2 × 10-4 s-1). The 47-electron clusters have lifetimes which are correlated with the oxidation potentials of the precursors, ranging from seconds to many hours at room temperature. Slow decomposition of [H3Ru3-(COMe)(CO)6L3]1+ in the absence of added CO forms the new 46-electron clusters [H3Ru3-(CO)7L3]1+ (L = PPh3, AsPh3). [H3Ru3(COMe)(CO)6(PPh3) 3]1+ does not react with CCl4 but does react with Lewis bases such as CO and acetonitrile. Disproportionation occurs with acetonitrile, chloride, and pyridine; the CO products are [HRu3(CO)9(PPh3)3]1+, [MePPh3]1+, and H3Ru3(COMe)(CO)9-n(PPH3)n (n = 1, 2).

AB - Cyclic voltammograms for H3Ru3(μ3-CX)(CO)9-nLn (X = OMe, SEt, Me, Et, Ph, NMeBz, Br; L = PR3, AsPh3, SbPh3; n = 2, 3), H3Ru3(μ3-COMe)(CO)6(PPh 3)2(L) (L = P(OMe)3, CNCH2-Ph), and H3Os3(μ3-COMe)(CO)7(PPh 3)2 each display a quasi-reversible to reversible, one-electron oxidation followed by an irreversible to quasi-reversible, one-electron oxidation. The ligand and substituent effects upon the oxidation potential are analyzed as an example of ligand additivity in a cluster system; the oxidation potential of the alkylidyne cluster core is as sensitive to π-donor substituent effects as are aromatic π complexes such as CpFe-(C5H4X) to substituents on the rings, and the dependence of the oxidation potential of the cluster upon ligand substitution on any given Ru atom is 37% of that expected for the oxidation of a monometallic complex. Reactions with 1 equiv of Ag+ or ferricenium give the 47-electron cations [H3Ru3(CX)(CO)6L3]1+ (X = OMe; L3 = (PPh3)2;Ĺ Ĺ = CO, PPh3, P(OMe)3, CNCH2Ph; X = Ph, NMeBz, SEt, L = PPh3), characterized by EPR spectroscopy; the equilibrium between isomers H3Ru3(COMe)(CO)6(ax-PPh3) 2(ax- and eq-PPh3)0/1+ (ax = axial coordination, eq = equatorial coordination) favors the axial coordination for the 48-electron cluster (eq/ax = 0.15) and equatorial coordination for the 47-electron species (eq/ax = 6.4). The rate constant for ax-eq isomerization for the 47-electron species (6.5 s-1) is 4 orders of magnitude greater than that for the 48-electron species (2 × 10-4 s-1). The 47-electron clusters have lifetimes which are correlated with the oxidation potentials of the precursors, ranging from seconds to many hours at room temperature. Slow decomposition of [H3Ru3-(COMe)(CO)6L3]1+ in the absence of added CO forms the new 46-electron clusters [H3Ru3-(CO)7L3]1+ (L = PPh3, AsPh3). [H3Ru3(COMe)(CO)6(PPh3) 3]1+ does not react with CCl4 but does react with Lewis bases such as CO and acetonitrile. Disproportionation occurs with acetonitrile, chloride, and pyridine; the CO products are [HRu3(CO)9(PPh3)3]1+, [MePPh3]1+, and H3Ru3(COMe)(CO)9-n(PPH3)n (n = 1, 2).

UR - https://www.scopus.com/pages/publications/0000678916

U2 - 10.1021/om970769t

DO - 10.1021/om970769t

M3 - Article

SN - 0276-7333

VL - 17

SP - 872

EP - 886

JO - Organometallics

JF - Organometallics

IS - 5

ER -

47-electron organometallic clusters derived by chemical and electrochemical oxidation of trihydrido(alkylidyne)triruthenium and -triosmium clusters. Ligand additivity in metal clusters

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