Rhenium-oxo-bis(acetylene) anions. Structure, properties, and electronic structure. Comparison of Re-O bonding with that in other rhenium-oxo complexes
- Memphis State Univ., TN (United States)
- Univ. of Washington, Seattle, WA (United States)
Reduction of Re(O)I(RC[triple bond]CR)[sub 2] (2) or [Re(O)(RC[triple bond]CR)[sub 2]][sub 2] by two electrons gives Re(O)(RC=[triple bond]CR)[sub 2]Na (R = Me, 1a; Et, 1b; Ph, 1c). Compounds 1 are unusual oxo complexes, being highly nucleophilic and strongly reducing. X-ray structures of 1a-crypt and 1c-2MeCN reveal Re(O)(RC[triple bond])[sub 2] units, as isolated anions in the former but, in the latter, connected via Na-O-Na bridges into centrosymmetric dimers. The acetylene ligands lie in a plane that is roughly perpendicular to the Re - O bond, but the C[triple bond]C vectors are splayed rather than parallel. The bond lengths and angles about rhenium are quite similar in the two structures, and quite close to the values found for 2 in which the splaying occurs to accommodate the iodide ligand. Reduction of 2a to 1a[center dot]crypt causes a lengthening of the Re-O bond from 1.697(3) to 1.745(7) [angstrom] and a drop in [nu][sub ReO] from 975 to 869 cm[sup [minus]1], both indicative of a decrease in the Re-O bond order. The Re-C distances and C[triple bond]C stretching frequencies both decrease on reduction, indicating increased Re [yields] acetylene back-bonding in 1. Effective core potential calculations on Re(O)(HC[triple bond]CH)[sub 2][sup [minus]] (A), Re(O)H(HC[triple bond]CH)[sub 2] (B), Re(O)Cl[sub 4][sup [minus]] (C), and Re(O)F[sub 5] (D) have been performed with excellent agreement between the calculated structures and experimental crystallographic data (A and B are models for 1 and 2). 49 refs., 5 figs., 4 tabs.
- OSTI ID:
- 5115980
- Journal Information:
- Organometallics; (United States), Vol. 13:1; ISSN 0276-7333
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ORGANOMETALLIC COMPOUNDS
ELECTRONIC STRUCTURE
MOLECULAR STRUCTURE
NUCLEAR MAGNETIC RESONANCE
X-RAY DIFFRACTION
RHENIUM COMPLEXES
CHEMICAL BONDS
LIGANDS
SODIUM COMPLEXES
THEORETICAL DATA
ALKALI METAL COMPLEXES
COHERENT SCATTERING
COMPLEXES
DATA
DIFFRACTION
INFORMATION
MAGNETIC RESONANCE
NUMERICAL DATA
ORGANIC COMPOUNDS
RESONANCE
SCATTERING
TRANSITION ELEMENT COMPLEXES
400201* - Chemical & Physicochemical Properties
400102 - Chemical & Spectral Procedures