Directed Synthesis of the Triangular Mixed-Metal Cluster H2RhRe2Cp*(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 H2Rh2Re2Cp*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)10 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 [ H = 25.0(8) kcal/mol; S = -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( -Cl)3Re(CO)3 (8). Heating 4 and H2S in benzene at ca. 60 ECmore »
- Authors:
-
- University of North Texas
- Texas Christian University
- San Diego State University
- ORNL
- Publication Date:
- Research Org.:
- Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)
- Sponsoring Org.:
- USDOE Office of Science (SC)
- OSTI Identifier:
- 970925
- DOE Contract Number:
- DE-AC05-00OR22725
- Resource Type:
- Journal Article
- Journal Name:
- Organometallics
- Additional Journal Information:
- Journal Volume: 29; Journal Issue: 1; Journal ID: ISSN 0276-7333
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 36 MATERIALS SCIENCE; BENZENE; CRYSTALLOGRAPHY; DIMERS; ELECTRONS; FRAGMENTATION; HEATING; HEXANE; HYDRIDES; KINETICS; OPENINGS; SOLVENTS; SPECTROSCOPY; SULFIDES; SYNTHESIS; THIOLS; TOLUENE; Mixed-metal clusters; Rhodium-Rhenium clusters; Metal hydrides; Cluster fragmentation; X-ray crystallography
Citation Formats
Huang, Shih-Huang Huang, Watson, William H., Carrano, Carl J., Wang, Xiaoping, and Richmond, Michael G. Directed Synthesis of the Triangular Mixed-Metal Cluster H2RhRe2Cp*(CO)9: Ligand Fluxionality and Facile Cluster Fragmentation in the Presence of CO, Halogenated Solvents, and Thiols. United States: N. p., 2010.
Web. doi:10.1021/om9007407.
Huang, Shih-Huang Huang, Watson, William H., Carrano, Carl J., Wang, Xiaoping, & Richmond, Michael G. Directed Synthesis of the Triangular Mixed-Metal Cluster H2RhRe2Cp*(CO)9: Ligand Fluxionality and Facile Cluster Fragmentation in the Presence of CO, Halogenated Solvents, and Thiols. United States. https://doi.org/10.1021/om9007407
Huang, Shih-Huang Huang, Watson, William H., Carrano, Carl J., Wang, Xiaoping, and Richmond, Michael G. 2010.
"Directed Synthesis of the Triangular Mixed-Metal Cluster H2RhRe2Cp*(CO)9: Ligand Fluxionality and Facile Cluster Fragmentation in the Presence of CO, Halogenated Solvents, and Thiols". United States. https://doi.org/10.1021/om9007407.
@article{osti_970925,
title = {Directed Synthesis of the Triangular Mixed-Metal Cluster H2RhRe2Cp*(CO)9: Ligand Fluxionality and Facile Cluster Fragmentation in the Presence of CO, Halogenated Solvents, and Thiols},
author = {Huang, Shih-Huang Huang and Watson, William H. and Carrano, Carl J. and Wang, Xiaoping and Richmond, Michael G.},
abstractNote = {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 H2Rh2Re2Cp*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)10 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 [ H = 25.0(8) kcal/mol; S = -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( -Cl)3Re(CO)3 (8). Heating 4 and H2S in benzene at ca. 60 EC 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( -SC6H4Me-p)3Re(CO)3 (11). The dinuclear compounds Cp*Rh( -Cl)( -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 spectroscopies and by X-ray crystallography. The reactivity displayed by 4 is contrasted with the known indenyl-substituted cluster H2Re2Ir( 5-ind)(CO)9 prepared earlier by Shapley and co-workers.},
doi = {10.1021/om9007407},
url = {https://www.osti.gov/biblio/970925},
journal = {Organometallics},
issn = {0276-7333},
number = 1,
volume = 29,
place = {United States},
year = {Fri Jan 01 00:00:00 EST 2010},
month = {Fri Jan 01 00:00:00 EST 2010}
}