Directed synthesis of the triangular mixed-metal cluster H 2RhRe2Cp*(CO)9: Ligand fluxionality and facile cluster fragmentation in the presence of CO, halogenated solvents, and thiols

Shih Huang Huang; William H. Watson; Carl J. Carrano; Xiaoping Wang; Michael G. Richmond

doi:10.1021/om9007407

Directed synthesis of the triangular mixed-metal cluster H ₂RhRe₂Cp*(CO)₉: Ligand fluxionality and facile cluster fragmentation in the presence of CO, halogenated solvents, and thiols

Shih Huang Huang
, William H. Watson
, Carl J. Carrano
, Xiaoping Wang
, Michael G. Richmond

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

13 Scopus citations

Abstract

The reaction Of H₂Re₂(CO)₈ (1) with Cp*Rh(CO)₂ (2) in refluxing hexane affords the mixed-metal clusters H₂RhRe₂Cp*(CO)₉ (4, major product), HRh₂ReCp*₂(CO)₆ (5), and HRhRe₃Cp*(CO)₁₄ (6). 4 and 5 are electron-precise 48e clusters and display triangular metallic cores, while 6 contains 64 valence electrons and exhibits a spiked-triangular core having a pendant Re(CO) ₅ moiety. Heating 1 with Cp*₂Rh₂(CO) ₂ (3) gives 4 and 5 as the principal products, in addition to H ₂Rh₂Re₂Cp*₂(CO)₈ (7) in low yield. Cluster 7 possesses 60e and contains a tetrametallic core with two face-capping CO and hydride groups. Heating 4 under CO leads to cluster fragmentation and formation of Re2(CO)io and 2 in essentially quantitative yield, as assessed by IR spectroscopy. The kinetics for the fragmentation of 4 in toluene under CO have been investigated over the temperature range 325-349 K by UV-vis spectroscopy. On the basis of the first-order rate constants and the Eyring activation parameters (ΔH‡ = 25.0(8) kcal/mol; ΔS‡ = -2.6(3) eu), a rate-limiting step involving a polyhedral opening of 4 is supported. 4 is thermally and photochemically sensitive, and reactions conducted in the presence of chlorinated solvents furnish the face-shared bioctahedral compound Cp*Rh(μ-Cl)₃Re(CO) ₃ (8). Heating 4 and H₂S in benzene at ca. 60 °C furnishes the 48e triangular cluster S₂Rh₃Cp*(CO) ₄ (9), which contains two Rh(CO)₂ moieties and two face-capping sulfide groups. The reaction of 4 with p-methylbenzenethiol gives the sulfido-bridged dimer Cp*Rh(μSC₆H₄Me-p) ₃Re(CO)₃ (11). The dinuclear compounds Cp*Rh(μ-Cl)(μ-SC₆H₄Me-p)₂Re(CO) ₃ (10) and 11 are formed when 8 is allowed to react with p-methylbenzenethiol. Treatment of 8 and 10 with excess p-methylbenzenethiol yields 11 at elevated temperature in toluene. Compounds 4-11 have been isolated and fully characterized by IR and NMR spectroscopy and by X-ray crystallography. The reactivity displayed by 4 is contrasted with that of the known indenyl-substituted cluster H₂Re₂Ir(η⁵-ind) (CO)₉ prepared earlier by Shapley and co-workers.

Original language	English
Pages (from-to)	61-75
Number of pages	15
Journal	Organometallics
Volume	29
Issue number	1
DOIs	https://doi.org/10.1021/om9007407
State	Published - Jan 11 2010

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@article{f0eaa45c37dd450fabf32361c2e14d2c,

title = "Directed synthesis of the triangular mixed-metal cluster H 2RhRe2Cp*(CO)9: Ligand fluxionality and facile cluster fragmentation in the presence of CO, halogenated solvents, and thiols",

abstract = "The reaction Of H2Re2(CO)8 (1) with Cp*Rh(CO)2 (2) in refluxing hexane affords the mixed-metal clusters H2RhRe2Cp*(CO)9 (4, major product), HRh2ReCp*2(CO)6 (5), and HRhRe3Cp*(CO)14 (6). 4 and 5 are electron-precise 48e clusters and display triangular metallic cores, while 6 contains 64 valence electrons and exhibits a spiked-triangular core having a pendant Re(CO) 5 moiety. Heating 1 with Cp*2Rh2(CO) 2 (3) gives 4 and 5 as the principal products, in addition to H 2Rh2Re2Cp*2(CO)8 (7) in low yield. Cluster 7 possesses 60e and contains a tetrametallic core with two face-capping CO and hydride groups. Heating 4 under CO leads to cluster fragmentation and formation of Re2(CO)io and 2 in essentially quantitative yield, as assessed by IR spectroscopy. The kinetics for the fragmentation of 4 in toluene under CO have been investigated over the temperature range 325-349 K by UV-vis spectroscopy. On the basis of the first-order rate constants and the Eyring activation parameters (ΔH‡ = 25.0(8) kcal/mol; ΔS‡ = -2.6(3) eu), a rate-limiting step involving a polyhedral opening of 4 is supported. 4 is thermally and photochemically sensitive, and reactions conducted in the presence of chlorinated solvents furnish the face-shared bioctahedral compound Cp*Rh(μ-Cl)3Re(CO) 3 (8). Heating 4 and H2S in benzene at ca. 60 °C furnishes the 48e triangular cluster S2Rh3Cp*(CO) 4 (9), which contains two Rh(CO)2 moieties and two face-capping sulfide groups. The reaction of 4 with p-methylbenzenethiol gives the sulfido-bridged dimer Cp*Rh(μSC6H4Me-p) 3Re(CO)3 (11). The dinuclear compounds Cp*Rh(μ-Cl)(μ-SC6H4Me-p)2Re(CO) 3 (10) and 11 are formed when 8 is allowed to react with p-methylbenzenethiol. Treatment of 8 and 10 with excess p-methylbenzenethiol yields 11 at elevated temperature in toluene. Compounds 4-11 have been isolated and fully characterized by IR and NMR spectroscopy and by X-ray crystallography. The reactivity displayed by 4 is contrasted with that of the known indenyl-substituted cluster H2Re2Ir(η5-ind) (CO)9 prepared earlier by Shapley and co-workers.",

author = "Huang, \{Shih Huang\} and Watson, \{William H.\} and Carrano, \{Carl J.\} and Xiaoping Wang and Richmond, \{Michael G.\}",

year = "2010",

month = jan,

day = "11",

doi = "10.1021/om9007407",

language = "English",

volume = "29",

pages = "61--75",

journal = "Organometallics",

issn = "0276-7333",

publisher = "American Chemical Society",

number = "1",

}

Directed synthesis of the triangular mixed-metal cluster H ₂RhRe₂Cp*(CO)₉: Ligand fluxionality and facile cluster fragmentation in the presence of CO, halogenated solvents, and thiols. / Huang, Shih Huang; Watson, William H.; Carrano, Carl J. et al.
In: Organometallics, Vol. 29, No. 1, 11.01.2010, p. 61-75.

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

TY - JOUR

T1 - Directed synthesis of the triangular mixed-metal cluster H 2RhRe2Cp*(CO)9

T2 - Ligand fluxionality and facile cluster fragmentation in the presence of CO, halogenated solvents, and thiols

AU - Huang, Shih Huang

AU - Watson, William H.

AU - Carrano, Carl J.

AU - Wang, Xiaoping

AU - Richmond, Michael G.

PY - 2010/1/11

Y1 - 2010/1/11

N2 - The reaction Of H2Re2(CO)8 (1) with Cp*Rh(CO)2 (2) in refluxing hexane affords the mixed-metal clusters H2RhRe2Cp*(CO)9 (4, major product), HRh2ReCp*2(CO)6 (5), and HRhRe3Cp*(CO)14 (6). 4 and 5 are electron-precise 48e clusters and display triangular metallic cores, while 6 contains 64 valence electrons and exhibits a spiked-triangular core having a pendant Re(CO) 5 moiety. Heating 1 with Cp*2Rh2(CO) 2 (3) gives 4 and 5 as the principal products, in addition to H 2Rh2Re2Cp*2(CO)8 (7) in low yield. Cluster 7 possesses 60e and contains a tetrametallic core with two face-capping CO and hydride groups. Heating 4 under CO leads to cluster fragmentation and formation of Re2(CO)io and 2 in essentially quantitative yield, as assessed by IR spectroscopy. The kinetics for the fragmentation of 4 in toluene under CO have been investigated over the temperature range 325-349 K by UV-vis spectroscopy. On the basis of the first-order rate constants and the Eyring activation parameters (ΔH‡ = 25.0(8) kcal/mol; ΔS‡ = -2.6(3) eu), a rate-limiting step involving a polyhedral opening of 4 is supported. 4 is thermally and photochemically sensitive, and reactions conducted in the presence of chlorinated solvents furnish the face-shared bioctahedral compound Cp*Rh(μ-Cl)3Re(CO) 3 (8). Heating 4 and H2S in benzene at ca. 60 °C furnishes the 48e triangular cluster S2Rh3Cp*(CO) 4 (9), which contains two Rh(CO)2 moieties and two face-capping sulfide groups. The reaction of 4 with p-methylbenzenethiol gives the sulfido-bridged dimer Cp*Rh(μSC6H4Me-p) 3Re(CO)3 (11). The dinuclear compounds Cp*Rh(μ-Cl)(μ-SC6H4Me-p)2Re(CO) 3 (10) and 11 are formed when 8 is allowed to react with p-methylbenzenethiol. Treatment of 8 and 10 with excess p-methylbenzenethiol yields 11 at elevated temperature in toluene. Compounds 4-11 have been isolated and fully characterized by IR and NMR spectroscopy and by X-ray crystallography. The reactivity displayed by 4 is contrasted with that of the known indenyl-substituted cluster H2Re2Ir(η5-ind) (CO)9 prepared earlier by Shapley and co-workers.

AB - The reaction Of H2Re2(CO)8 (1) with Cp*Rh(CO)2 (2) in refluxing hexane affords the mixed-metal clusters H2RhRe2Cp*(CO)9 (4, major product), HRh2ReCp*2(CO)6 (5), and HRhRe3Cp*(CO)14 (6). 4 and 5 are electron-precise 48e clusters and display triangular metallic cores, while 6 contains 64 valence electrons and exhibits a spiked-triangular core having a pendant Re(CO) 5 moiety. Heating 1 with Cp*2Rh2(CO) 2 (3) gives 4 and 5 as the principal products, in addition to H 2Rh2Re2Cp*2(CO)8 (7) in low yield. Cluster 7 possesses 60e and contains a tetrametallic core with two face-capping CO and hydride groups. Heating 4 under CO leads to cluster fragmentation and formation of Re2(CO)io and 2 in essentially quantitative yield, as assessed by IR spectroscopy. The kinetics for the fragmentation of 4 in toluene under CO have been investigated over the temperature range 325-349 K by UV-vis spectroscopy. On the basis of the first-order rate constants and the Eyring activation parameters (ΔH‡ = 25.0(8) kcal/mol; ΔS‡ = -2.6(3) eu), a rate-limiting step involving a polyhedral opening of 4 is supported. 4 is thermally and photochemically sensitive, and reactions conducted in the presence of chlorinated solvents furnish the face-shared bioctahedral compound Cp*Rh(μ-Cl)3Re(CO) 3 (8). Heating 4 and H2S in benzene at ca. 60 °C furnishes the 48e triangular cluster S2Rh3Cp*(CO) 4 (9), which contains two Rh(CO)2 moieties and two face-capping sulfide groups. The reaction of 4 with p-methylbenzenethiol gives the sulfido-bridged dimer Cp*Rh(μSC6H4Me-p) 3Re(CO)3 (11). The dinuclear compounds Cp*Rh(μ-Cl)(μ-SC6H4Me-p)2Re(CO) 3 (10) and 11 are formed when 8 is allowed to react with p-methylbenzenethiol. Treatment of 8 and 10 with excess p-methylbenzenethiol yields 11 at elevated temperature in toluene. Compounds 4-11 have been isolated and fully characterized by IR and NMR spectroscopy and by X-ray crystallography. The reactivity displayed by 4 is contrasted with that of the known indenyl-substituted cluster H2Re2Ir(η5-ind) (CO)9 prepared earlier by Shapley and co-workers.

UR - https://www.scopus.com/pages/publications/73649123132

U2 - 10.1021/om9007407

DO - 10.1021/om9007407

M3 - Article

AN - SCOPUS:73649123132

SN - 0276-7333

VL - 29

SP - 61

EP - 75

JO - Organometallics

JF - Organometallics

IS - 1

ER -

Directed synthesis of the triangular mixed-metal cluster H ₂RhRe₂Cp*(CO)₉: Ligand fluxionality and facile cluster fragmentation in the presence of CO, halogenated solvents, and thiols

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