Journal article
Permethyltitanocene Derivatives with Naked Chalcogen Ligands: Synthesis of [(Cp2Ti)2(μ-E)] and [Cp2Ti(μ2-E2)] and the Role of the Terminal Chalcogenides [Cp2Ti(E)] in Their Interconversion (E = Se, Te)
Chemistry : a European journal, Vol.2(10), pp.1221-1229
10/1996
DOI: 10.1002/chem.19960021007
Abstract
Permethyltitanocene hydride, [Cp2*TiH], reacts with elemental selenium or tellurium to give the products [(Cp2*Ti) 2(μ-E)] (E = Se, 1a; Te, 1b), [Cp2*Ti(η 2-E2)] (E = Se, 2a; Te, 2b) and [Cp 2*Ti(η2-Se3)] (3), depending on the equivalency of the chalcogen employed. Dinuclear compounds 1 are paramagnetic and have D2d (idealized) structures, as shown by X-ray structural analysis of μ-telluride 1b; they may be converted to diamagnetic dichalcogenides 2 through further reaction with the appropriate chalcogen. Derivatives 2 are monomeric in the solid state, as shown by X-ray structural analysis of ditelluride 2b, and in solution, as demonstrated by multinuclear NMR spectroscopy. Combination of diselenide 2a and ditelluride 2b results in partial redistribution to the mixed species [Cp2*Ti(η 2-SeTe)], suggesting dimeric structures of formula [Cp 2*Ti(μ-E-E)2TiCp2*] may be accessible in solution. The dichalcogenides and the triselenide may be converted back to complexes 1 by treatment with a chalcogen-abstracting agent. The possible involvement of monomeric terminal chalcogenides [Cp2* Ti(E)] in the interconversion of 1 and 2 was probed experimentally and computationally by means of Density Functional Theory calculations on [Cp 2M(E)] (M = Ti, E = O, S, Se, Te; M = Zr, E = O, Te). Several unsuccessful attempts to generate and trap [Cp2*Ti(Te)] are described. The results of these studies suggest that [Cp2* Ti(Te)] has a very weak Ti-Te bond and a readily accessible triplet excited state. These factors, along with the small size of titanium, render this member of the [Cp2*M(E)] family of complexes difficult to trap with Lewis bases, in contrast to many other congeners in the series of Group 4 terminal chalcogenides.
Details
- Title: Subtitle
- Permethyltitanocene Derivatives with Naked Chalcogen Ligands: Synthesis of [(Cp2Ti)2(μ-E)] and [Cp2Ti(μ2-E2)] and the Role of the Terminal Chalcogenides [Cp2Ti(E)] in Their Interconversion (E = Se, Te)
- Creators
- Warren E Piers - Department of Chemistry, The University of Calgary 2500 University Drive N. W., Calgary, Alberta, T2N 1N4 (Canada) Fax: Int. code +289-9488Tom Ziegler - Department of Chemistry, The University of Calgary 2500 University Drive N. W., Calgary, Alberta, T2N 1N4 (Canada) Fax: Int. code +289-9488Jason M Fischer - Department of Chemistry and Biochemistry, University of Guelph Guelph, Ontario N1G 2W1 (Canada)Leonard R Macgillivray - Department of Chemistry, Saint Mary's University Halifax, Nova Scotia B3H 3C3 (Canada)Michael J Zaworotko - Department of Chemistry, Saint Mary's University Halifax, Nova Scotia B3H 3C3 (Canada)
- Resource Type
- Journal article
- Publication Details
- Chemistry : a European journal, Vol.2(10), pp.1221-1229
- Publisher
- WILEY-VCH Verlag
- DOI
- 10.1002/chem.19960021007
- ISSN
- 0947-6539
- eISSN
- 1521-3765
- Number of pages
- 9
- Language
- English
- Date published
- 10/1996
- Academic Unit
- Chemistry; Pharmaceutical Sciences and Experimental Therapeutics
- Record Identifier
- 9984216588102771
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