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 · Wed Nov 30 23:00:00 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), Journal Name: Organometallics; (United States) Vol. 13:12; ISSN ORGND7; ISSN 0276-7333
• Country of Publication: United States
• Language: English

Related Subjects

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