Conversion of nitriles to nitrenes via azavinylidenes in low-valent tungsten carbonyl complexes
- Univ. of North Carolina, Chapel Hill, NC (United States)
Azavinylidene complexes of the type Tp[prime](CO)[sub 2]W=N=CRNu are available from the reaction of [Tp[prime](CO)[sub 3]W(N=CR)][BF[sub 4]] with nucleophiles (Tp[prime] = hydridotris(3,5-dimethylpyrazolyl)borate; R = Me, Nu = H (1a); R = Ph, Nu = Et (1d); R = Me, Nu = MeO (1e)). Related azavinylidene complexes Tp[prime](CO)[sub 2]W=N=CHR (R = Me (1a); R = Et (1b); R = CH[sub 2]Ph (1c)) form via insertion of nitrile into the W-H bond of Tp[prime](CO)[sub 3]WH when the metal reagent is photolyzed in the presence of nitriles. Donation of the lone pair of electrons from the azavinylidene nitrogen to the tungsten center, compatible with electron counting guidelines, is reflected in the low IR stretching frequencies of the carbonyl ligands and their downfield carbon resonance in [sup 15]C NMR. NMR spectra and an X-ray structure of Tp[prime](CO)[sub 2]W=N=CHCH[sub 3]Ph (1c) indicate that the azavinylidene ligand is nearly linear ([sup 3]J[sub WH] = 5.6 Hz, [sup 2]J[sub WC] = 27 Hz, and [alpha](W-N-C) = 166.6(7)[degree]). Complex 1c crystallized in the monoclinic space group P2[sub 1]/n with unit cell dimensions of a = 12.163(1), b = 17.207(2), and c = 13.312(1) [angstrom] and [beta] = 102.103(7)[degree], with Z = 4. 32 refs., 2 figs., 5 tabs.
- OSTI ID:
- 6840930
- Journal Information:
- Journal of the American Chemical Society; (United States), Vol. 116:19; ISSN 0002-7863
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
TUNGSTEN COMPLEXES
CRYSTAL STRUCTURE
NUCLEAR MAGNETIC RESONANCE
SYNTHESIS
X-RAY DIFFRACTION
COMPILED DATA
LIGANDS
NITRILES
ORGANOMETALLIC COMPOUNDS
PHOTOLYSIS
CHEMICAL REACTIONS
COHERENT SCATTERING
COMPLEXES
DATA
DECOMPOSITION
DIFFRACTION
INFORMATION
MAGNETIC RESONANCE
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
RESONANCE
SCATTERING
TRANSITION ELEMENT COMPLEXES
400201* - Chemical & Physicochemical Properties
400500 - Photochemistry
400102 - Chemical & Spectral Procedures