Acyl, carbene, vinyl, and azavinylidene ligands in tungsten(II) hydridotris(3,5-dimethylpyrazolyl)borate alkyne complexes

Journal Article · Tue Jun 01 00:00:00 EDT 1993 · Organometallics; (United States)

DOI:https://doi.org/10.1021/om00030a025· OSTI ID:6235327

Feng, S G; White, P S; Templeton, J L ^[1]

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1. Univ. of North Carolina, Chapel Hill (United States)

Reaction of [Tp'(CO)[sub 2]W(PhC[sub 2]Me)][BF[sub 4]] with LiCuR[sub 2] (R = Ph, Me) generates neutral [eta][sup 1]-acyl complexes Tp'(CO)(PhC[sub 2]Me)W([eta][sup 1]-C(O)R) in which the alkyne ligand remains as a four-electron donor. Deprotonation of the alkyne methyl in Tp'(CO)PhC[sub 2]MeW([eta][sup 1]-C(O)Me) produces a nucleophilic propargyl synthon which reacts with MeI to yield an ethyl alkyne complex. Protonation or methylation of the neutral [eta][sup 1]-acyl complexes at the acyl oxygen results in the formation of Fischer-type hydroxy- or methoxycarbene cations, [Tp'(CO)(PhC[sub 2]Me)W=C(OE)R][sup +] (E = H, Me; R = Me, Ph, n-C[sub 4]H[sub 9]). Crystals of the methoxybutylcarbene complex belong to the orthorhombic space group P2[sub 1]2[sub 1]2[sub 1], Z = 4, with unit cell dimensions of a = 15.090(6), b = 16.562(4), and c = 14.624(4) A. Refinement of 273 variables over 2187 reflections led to an R value of 6.4% with R[sub w] = 6.7%. The alkyne ligand aligns itself parallel to the cis metal-carbonyl axis and perpendicular to the plane of the carbene ligand. Reaction of [Tp'(PhC[sub 2]Me)W=C(OMe)Me]CF[sub 3]SO[sub 3] with NaOH in MeOH generates a neutral [sigma]-vinyl complex, Tp'(CO)(PhC[sub 2]Me)W([eta][sup 1]-C(OMe)=CH[sub 2]), via deprotonation of the carbene methyl group. Reaction of [Tp'(CO)(PhC[sub 2]Me)W=C(OMe)Ph][CF[sub 3]SO[sub 3]] with 2 equiv of KCN in MeOH yields a neutral azavinylidene complex, Tp'(CO)(PhC[sub 2]Me)WN=C(CN)CH(OMe)Ph, in which the lone pair of electrons on the nitrogen of the azavinylidene ligand competes with the alkyne [pi] donor orbital for donation to the lone vacant metal d[pi] orbital. 35 refs., 2 figs., 3 tabs.

• OSTI ID: 6235327
• Journal Information: Organometallics; (United States), Vol. 12:6; ISSN 0276-7333
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
TUNGSTEN COMPLEXES
CHEMICAL REACTIONS
CRYSTAL STRUCTURE
SYNTHESIS
ELECTRONIC STRUCTURE
EXPERIMENTAL DATA
LIGANDS
METHYLATION
NUCLEAR MAGNETIC RESONANCE
ORGANOMETALLIC COMPOUNDS
X-RAY DIFFRACTION
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