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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

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 » 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.« less

Authors:
 [1];  [2];  [3];  [4];  [1]
  1. University of North Texas
  2. Texas Christian University
  3. San Diego State University
  4. 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}
}