Journal article
A Planar Tetracoordinate Carbon and Unusual Bonding in an Organodimetallic Propynylidene Complex Arising from Double C−H Activation of an Allene Ligand
Journal of the American Chemical Society, Vol.125(7), pp.1688-1689
02/19/2003
DOI: 10.1021/ja020369j
PMID: 12580580
Abstract
Reduction of the organoditantalum allene complex (η-C5Me4R)2Ta2(μ-X)X3(μ-η,η3-C3H4) (R = Me (Cp*), Et; X = Cl, Br) with sodium amalgam leads to the propynylidene complex (η-C5Me4R)2Ta2(μ-H)2X2(μ-HCCCH) by a formal double 1,3-C−H activation of the allene ligand. The solid-state molecular structure contains a planar HCCCH ligand bridging, in parallel coordination mode, the two tantalum atoms, with the HCCCH and Ta atoms coplanar. Key structural features are a Ta−Ta distance of 2.8817(7) Å, propynylidene C−C−C angle of 153.7(13)°, C−C distance of 1.370(8) Å, Ta−C(central) distance of 2.194(9) Å, and Ta−C(terminal) distance of 1.970(9) Å. Molecular orbital calculations on the complex at the RHF/SBK(d) and B3LYP/LanL2dz levels of theory demonstrate that the propynylidene ligand is best viewed formally as an allenediylidene(4−) ligand bonded to two d0 tantalum atoms via two TaC(terminal) double bonds and an unusual three-center, two-electron bridge bond involving both tantalum atoms and a lone pair on the planar, tetracoordinate central carbon. There is no net Ta−Ta bonding based on the orbital analysis.
Details
- Title: Subtitle
- A Planar Tetracoordinate Carbon and Unusual Bonding in an Organodimetallic Propynylidene Complex Arising from Double C−H Activation of an Allene Ligand
- Creators
- Jui-Hsien HuangJeffrey J LuciTing-Yu LeeDale C SwensonJan H JensenLouis Messerle
- Resource Type
- Journal article
- Publication Details
- Journal of the American Chemical Society, Vol.125(7), pp.1688-1689
- Publisher
- American Chemical Society
- DOI
- 10.1021/ja020369j
- PMID
- 12580580
- ISSN
- 0002-7863
- eISSN
- 1520-5126
- Language
- English
- Date published
- 02/19/2003
- Academic Unit
- Radiology; Chemistry
- Record Identifier
- 9983985925302771
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