Mixed-metal cluster chemistry: 32. Synthesis, structure, and reactivity of a trimetallic molybdenum–iridium carbonyl cluster possessing a μ3-η2-benzyne ligand
The reaction of Mo2Ir2(μ-CO)3(CO)7(η5-C5H5)2 and Ir(C <img border="0" alt="triple bond; length of mdash" src="<a href="http://cdn.els-cdn.com/sd/entities/tbnd">http://cdn.els-cdn.com/sd/entities/tbnd</a>" class="glyphImg">CCH2OH)(CO...
| Main Authors: | , , , , , , , |
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| Format: | Journal Article |
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2013
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| Online Access: | http://hdl.handle.net/20.500.11937/12370 |
| _version_ | 1848748057481445376 |
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| author | Randles, M. Gupta, V. Simpson, Peter Moxey, G. Criddle, A. Stranger, R. Cifuentes, M. Humphrey, M. |
| author_facet | Randles, M. Gupta, V. Simpson, Peter Moxey, G. Criddle, A. Stranger, R. Cifuentes, M. Humphrey, M. |
| author_sort | Randles, M. |
| building | Curtin Institutional Repository |
| collection | Online Access |
| description | The reaction of Mo2Ir2(μ-CO)3(CO)7(η5-C5H5)2 and Ir(C <img border="0" alt="triple bond; length of mdash" src="<a href="http://cdn.els-cdn.com/sd/entities/tbnd">http://cdn.els-cdn.com/sd/entities/tbnd</a>" class="glyphImg">CCH2OH)(CO)(PPh3)3 in refluxing toluene gives the molybdenum–iridium cluster MoIr2(μ3-η2-C6H4)(μ-PPh2)(μ-CO)2(CO)4(η5-C5H5) (1) in low yield. Mo2Ir2(μ-CO)3(CO)6(PPh3)(η5-C5H5)2 (2) is a possible intermediate en route to 1; reaction of Mo2Ir2(μ-CO)3(CO)7(η5-C5H5)2 and Ir(C <img border="0" alt="triple bond; length of mdash" src="<a href="http://cdn.els-cdn.com/sd/entities/tbnd">http://cdn.els-cdn.com/sd/entities/tbnd</a>" class="glyphImg">CCH2OH)(CO)(PPh3)3 in refluxing dichloromethane affords low yields of 2, and thermolysis of the latter in refluxing toluene gives modest yields of 1. A structural study reveals that 1 consists of a triangular MoIr2 core with a molybdenum-bound cyclopentadienyl group, two terminal carbonyls at each of the iridium atoms, one carbonyl bridging each of the Mo–Ir bonds, and a PPh2 moiety spanning the Ir–Ir linkage. The cluster coordination sphere is completed by a face-capping benzyne ligand that ligates η1- to each iridium atom and η2- to the group 6 metal. A structural study of 2 confirms the tetranuclear Mo2Ir2 core with molybdenum-bound cyclopentadienyl groups, six terminal and three-edge-bridging carbonyls, the latter deployed about an MoIr2 face, and a triphenylphosphine ligand ligated axially with respect to the carbonyl-bridged plane. Reaction of 1 with PPh3 in refluxing toluene gives MoIr2(μ3-η2-C6H4)(μ-PPh2)(μ-CO)2(CO)3(PPh3)(η5-C5H5) (3) in low yield. While X-ray structural authentication of 3 has thus far proven elusive, theoretical studies indicate that an equatorially substituted structure is favored energetically over the axially-substituted isomer by around 20 kJ mol−1, but this energy difference is not sufficiently large so as to exclude formation of the axial isomer experimentally. |
| first_indexed | 2025-11-14T06:58:59Z |
| format | Journal Article |
| id | curtin-20.500.11937-12370 |
| institution | Curtin University Malaysia |
| institution_category | Local University |
| last_indexed | 2025-11-14T06:58:59Z |
| publishDate | 2013 |
| recordtype | eprints |
| repository_type | Digital Repository |
| spelling | curtin-20.500.11937-123702017-09-13T14:56:51Z Mixed-metal cluster chemistry: 32. Synthesis, structure, and reactivity of a trimetallic molybdenum–iridium carbonyl cluster possessing a μ3-η2-benzyne ligand Randles, M. Gupta, V. Simpson, Peter Moxey, G. Criddle, A. Stranger, R. Cifuentes, M. Humphrey, M. The reaction of Mo2Ir2(μ-CO)3(CO)7(η5-C5H5)2 and Ir(C <img border="0" alt="triple bond; length of mdash" src="<a href="http://cdn.els-cdn.com/sd/entities/tbnd">http://cdn.els-cdn.com/sd/entities/tbnd</a>" class="glyphImg">CCH2OH)(CO)(PPh3)3 in refluxing toluene gives the molybdenum–iridium cluster MoIr2(μ3-η2-C6H4)(μ-PPh2)(μ-CO)2(CO)4(η5-C5H5) (1) in low yield. Mo2Ir2(μ-CO)3(CO)6(PPh3)(η5-C5H5)2 (2) is a possible intermediate en route to 1; reaction of Mo2Ir2(μ-CO)3(CO)7(η5-C5H5)2 and Ir(C <img border="0" alt="triple bond; length of mdash" src="<a href="http://cdn.els-cdn.com/sd/entities/tbnd">http://cdn.els-cdn.com/sd/entities/tbnd</a>" class="glyphImg">CCH2OH)(CO)(PPh3)3 in refluxing dichloromethane affords low yields of 2, and thermolysis of the latter in refluxing toluene gives modest yields of 1. A structural study reveals that 1 consists of a triangular MoIr2 core with a molybdenum-bound cyclopentadienyl group, two terminal carbonyls at each of the iridium atoms, one carbonyl bridging each of the Mo–Ir bonds, and a PPh2 moiety spanning the Ir–Ir linkage. The cluster coordination sphere is completed by a face-capping benzyne ligand that ligates η1- to each iridium atom and η2- to the group 6 metal. A structural study of 2 confirms the tetranuclear Mo2Ir2 core with molybdenum-bound cyclopentadienyl groups, six terminal and three-edge-bridging carbonyls, the latter deployed about an MoIr2 face, and a triphenylphosphine ligand ligated axially with respect to the carbonyl-bridged plane. Reaction of 1 with PPh3 in refluxing toluene gives MoIr2(μ3-η2-C6H4)(μ-PPh2)(μ-CO)2(CO)3(PPh3)(η5-C5H5) (3) in low yield. While X-ray structural authentication of 3 has thus far proven elusive, theoretical studies indicate that an equatorially substituted structure is favored energetically over the axially-substituted isomer by around 20 kJ mol−1, but this energy difference is not sufficiently large so as to exclude formation of the axial isomer experimentally. 2013 Journal Article http://hdl.handle.net/20.500.11937/12370 10.1016/j.poly.2012.07.018 restricted |
| spellingShingle | Randles, M. Gupta, V. Simpson, Peter Moxey, G. Criddle, A. Stranger, R. Cifuentes, M. Humphrey, M. Mixed-metal cluster chemistry: 32. Synthesis, structure, and reactivity of a trimetallic molybdenum–iridium carbonyl cluster possessing a μ3-η2-benzyne ligand |
| title | Mixed-metal cluster chemistry: 32. Synthesis, structure, and reactivity of a trimetallic molybdenum–iridium carbonyl cluster possessing a μ3-η2-benzyne ligand |
| title_full | Mixed-metal cluster chemistry: 32. Synthesis, structure, and reactivity of a trimetallic molybdenum–iridium carbonyl cluster possessing a μ3-η2-benzyne ligand |
| title_fullStr | Mixed-metal cluster chemistry: 32. Synthesis, structure, and reactivity of a trimetallic molybdenum–iridium carbonyl cluster possessing a μ3-η2-benzyne ligand |
| title_full_unstemmed | Mixed-metal cluster chemistry: 32. Synthesis, structure, and reactivity of a trimetallic molybdenum–iridium carbonyl cluster possessing a μ3-η2-benzyne ligand |
| title_short | Mixed-metal cluster chemistry: 32. Synthesis, structure, and reactivity of a trimetallic molybdenum–iridium carbonyl cluster possessing a μ3-η2-benzyne ligand |
| title_sort | mixed-metal cluster chemistry: 32. synthesis, structure, and reactivity of a trimetallic molybdenum–iridium carbonyl cluster possessing a μ3-η2-benzyne ligand |
| url | http://hdl.handle.net/20.500.11937/12370 |