Exclusion of six-coordinate intermediates in the electrochemical reduction of CO[sub 2] catalyzed by [Pd(triphosphine)(CH[sub 3]CN)](BF[sub 4])[sub 2] complexes

Journal Article · Thu Dec 01 00:00:00 EST 1994 · Organometallics; (United States)

DOI:https://doi.org/10.1021/om00024a029· OSTI ID:6730704

Bernatis, P R; Miedaner, A; DuBois, D L ^[1]; Haltiwanger, R C ^[2]

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1. National Renewable Energy Lab., Golden, CO (United States)
2. Univ. of Colorado, Boulder, CO (United States)

[Pd(triphosphine)(CH[sub 3]CN)](BF[sub 4])[sub 2] complexes have been prepared with mesityl or trimethoxybenzene substituents on the central phosphorus atom of the triphosphine ligand. An X-ray diffraction study of [Pd(MesetpE)(CH[sub 3]CN)](BF[sub 4])[sub 2] (where MesetpE is bis((diethylphosphino)ethyl)mesitylphosphine) has been completed. [Pd(MesetpE)(CH[sub 3]CN)](BF[sub 4])[sub 2] crystallizes in space group P[bar 1] with a = 10.370(2) angstroms, b = 11.009(2) angstroms, c = 14.483(2) angstroms, [alpha] = 103.203(13)[degrees], [beta] = 92.748(16)[degrees], [gamma] = 922.556(15)[degrees], V = 1605.2(5) angstroms[sup 3], and Z = 2. The structure was refined to R = 0.0659 and R[sub w] = 0.0771 for 4467 independent reflections with F > 4[sigma](F). The cation has a square-planar structure with one methyl group of the central mesityl substituent blocking one potential coordination site. Kinetic studies of this complex in dimethylformamide indicate that the rate-determining step is the reaction of the [(Pd)MesetpE(DMF)][sup +] cation with CO[sub 2]. Comparison of the rate constants for this and other mesityl-substituted complexes with those of other [Pd(triphosphine)(CH[sub 3]CN)](BF[sub 4])[sub 2] complexes suggests that all proceed through a five-coordinate transition state. 30 refs., 5 figs., 5 tabs.

• OSTI ID: 6730704
• Journal Information: Organometallics; (United States), Vol. 13:12; ISSN 0276-7333
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
CARBON DIOXIDE
REDUCTION
PALLADIUM COMPLEXES
CRYSTALLOGRAPHY
SYNTHESIS
X-RAY DIFFRACTION
AMINES
CARBONIC ACID ESTERS
CATALYSIS
COMPILED DATA
ELECTROCHEMISTRY
FORMIC ACID
LIGANDS
NUCLEAR MAGNETIC RESONANCE
ORGANOMETALLIC COMPOUNDS
VOLTAMETRY
CARBON COMPOUNDS
CARBON OXIDES
CARBOXYLIC ACIDS
CHALCOGENIDES
CHEMICAL REACTIONS
CHEMISTRY
COHERENT SCATTERING
COMPLEXES
DATA
DIFFRACTION
ESTERS
INFORMATION
MAGNETIC RESONANCE
MONOCARBOXYLIC ACIDS
NUMERICAL DATA
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXIDES
OXYGEN COMPOUNDS
RESONANCE
SCATTERING
TRANSITION ELEMENT COMPLEXES
400201* - Chemical & Physicochemical Properties
400102 - Chemical & Spectral Procedures