Preparation and reactivity of tungsten(VI) metallacyclobutane complexes. Square pyramids versus trigonal bipyramids
- Massachusetts Inst. of Tech., Cambridge (United States)
Neopentylidene complexes of the type W(CH-t-Bu)(NAr)(OR){sub 2} (Ar = 2,6-C{sub 6}H{sub 3}-i-Pr{sub 2}; OR = O-t-Bu, OCMe{sub 2}(CF{sub 3}), OAr) react with ethylene to give trigonal-bipyramidal or square-pyramidal tungstacyclobutane complexes. A square-pyramidal form is observed when OR = O-t-Bu. Both forms are present when OR = OCMe{sub 2}(CF{sub 3}) or OAr, and they interconvert at a rate that is on the order of the NMR time scale. W(CH{sub 2}CH(t-Bu)CH{sub 2})(NAr)(OCMe{sub 2}(CF{sub 3})){sub 2} has been characterized crystallographically, and the crystal parameters are reported. The most characteristic feature of the WC{sub 3} ring in the SP complex is the relatively normal W---C{sub {beta}} distance of {approximately}2.8 {angstrom} and W-C{sub {alpha}} bond lengths of 2.15-2.20 {angstrom}, as opposed to a short W---C{sub {beta}} distance of {approximately}2.4 {angstrom} and W-C{sub {alpha}} bond lengths of 2.05-2.10 {angstrom} in TBP complexes.
- DOE Contract Number:
- FG05-86ER75292
- OSTI ID:
- 6106704
- Journal Information:
- Organometallics; (United States), Journal Name: Organometallics; (United States) Vol. 9:9; ISSN 0276-7333; ISSN ORGND
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
400201* -- Chemical & Physicochemical Properties
ALKANES
ALKENES
BOND ANGLE
BOND LENGTHS
CATALYTIC EFFECTS
CHEMICAL PREPARATION
CHEMICAL REACTION KINETICS
COHERENT SCATTERING
COMPLEXES
CYCLOALKANES
DIFFRACTION
DIMENSIONS
ENERGY
ETHYLENE
FREE ENTHALPY
HYDRIDES
HYDROCARBONS
HYDROGEN COMPOUNDS
KINETICS
LENGTH
LIGANDS
LITHIUM COMPLEXES
LOW TEMPERATURE
MOLECULAR STRUCTURE
NMR SPECTRA
ORGANIC COMPOUNDS
ORGANIC SILICON COMPOUNDS
PHOSPHINES
PHOSPHORUS COMPOUNDS
PHYSICAL PROPERTIES
REACTION INTERMEDIATES
REACTION KINETICS
SCATTERING
SILANES
SILICON COMPOUNDS
SPECTRA
SYNTHESIS
THERMODYNAMIC PROPERTIES
TRANSITION ELEMENT COMPLEXES
TUNGSTEN COMPLEXES
X-RAY DIFFRACTION