Begum, S;
Chowdhury, A;
Ghosh, S;
Tocher, DA;
Rosenberg, E;
Hardcastle, K;
Kabir, S;
(2018)
Reaction of electron-deficient 6-methoxyquinolinate-substituted cluster [Os3(CO)9{μ3-η1,κ1-C9H5N(6-OMe)}(μ-H)] with PPh3: Thermally induced ligand isomerization, decarbonylation and orthometallation.
Inorganica Chimica Acta
, 478
pp. 25-31.
10.1016/j.ica.2018.03.045.
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Abstract
The reaction of the electron-deficient 6-methoxyquinolinate-substituted triosmium cluster [Os3(CO)9{μ3-η1,κ1-C9H5N(6-OMe)}(μ-H)] (1) with PPh3 proceeds readily at room temperature to afford the electron-precise adduct [Os3(CO)9(PPh3){μ-η1,κ1-C9H5N(6-OMe)}(μ-H)] (2), in which the PPh3 ligand is bound to the osmium that serves as the coordination site for the hydride and the metallated-carbon atom of the benzoheterocycle. This reaction also leads to a change in the hapticity of the 6-methoxyquinolinate ligand from μ3-η1,κ1 to μ-η1,κ1 as confirmed by X-ray crystallography. Thermolysis of 2 in boiling toluene furnishes five new triosmium clusters (3–7) as a result of ligand isomerization, decarbonylation and orthometallation of the ancillary PPh3 ligand. Clusters 3 and 4 are isomers of 2 and the location of the metal-bound hydride and PPh3 with respect to 6-methoxyquinolinate moiety is the only difference between these isomers. Control experiments show that 5 is a decarbonylation product of 4 which converts into 6 as a result of further decarbonylation with concomitant orthometallation of one of the phenyl rings of the coordinated PPh3 ligand, whilst 7 is formed from 6 through replacement of an equatorial carbonyl of the nitrogen-bound osmium by PPh3 ligand. All the new clusters have been characterized by a combination of analytical and spectroscopic methods as well as by X-ray crystallography in the case of 2, 3, 6 and 7.
| Type: | Article |
|---|---|
| Title: | Reaction of electron-deficient 6-methoxyquinolinate-substituted cluster [Os3(CO)9{μ3-η1,κ1-C9H5N(6-OMe)}(μ-H)] with PPh3: Thermally induced ligand isomerization, decarbonylation and orthometallation |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1016/j.ica.2018.03.045 |
| Publisher version: | https://doi.org/10.1016/j.ica.2018.03.045 |
| Language: | English |
| Additional information: | This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | Triosmium clusters; 6-Methoxyquinoline; Triphenylphosphine; Isomerization; Decarbonylation; Orthometallation |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Chemistry |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10046125 |
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