Coordinatively unsaturated tripalladium and triplatinum clusters: Models for reactions on metal surfaces

Puddephatt, Richard J.; Manojlović-Muir, Ljubica; Muir, Kenneth W.

doi:10.1016/s0277-5387(00)84182-0

Cited by 138 publications

(92 citation statements)

References 103 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…+ , the mechanism involves, in a first equilibrated step, the formation of a hydroxide adduct, [Pd 3 …”

Section: -Co)a C H T U N G T R E N N U N G (Dppm) ]mentioning

confidence: 99%

“…Since the first report on the synthesis and characterisation of the [Pd 3 n + throughout this manuscript in which n = 0, 1, 2; dppm = bis-A C H T U N G T R E N N U N G (diphenylphosphino)methane) in the 1980s, by Puddephatt et al, [1][2][3] and its Pt analogue, [4] numerous and exhaustive studies on its reactivity and properties have appeared in the literature. [5][6][7][8][9][10] This cluster exhibits a triangular Pd 3 (M 3 ) centre with three dppm-supported M À M single bonds.…”

Section: Introductionmentioning

confidence: 99%

“…From electron paramagnetic resonance analysis of the reaction medium using the spin-trap agent 5,5-dimethyl-1-pyrroline-N-oxide (DMPO), the 2-tetrahydrofuryl or methyl radicals, deriving from the tetrahydrofuran (THF) or dimethyl sulfoxide (DMSO) solvent, respectively, were detected. For both [Pd 3 A C H T U N G T R E N N U N G (m…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Unexpected Reaction of the Unsaturated Cluster Host and Catalyst [Pd₃(μ³‐CO)(dppm)₃]²⁺ with the Hydroxide Ion: Spectroscopic and Kinetic Evidence of an Inner‐Sphere Mechanism

Cugnet

Lucas

Lemaître

et al. 2006

Chemistry A European J

View full text Add to dashboard Cite

The title cluster, [Pd(3)(mu(3)-CO)(dppm)(3)](2+) (dppm=bis(diphenylphosphino)methane), reacts with one equivalent of hydroxide anions (OH(-)), from tetrabutylammonium hydroxide (Bu(4)NOH), to give the paramagnetic [Pd(3)(mu(3)-CO)(dppm)(3)](+) species. Reaction with another equivalent of OH(-) leads to the zero-valent compound [Pd(3)(mu(3)-CO)(dppm)(3)](0). From electron paramagnetic resonance analysis of the reaction medium using the spin-trap agent 5,5-dimethyl-1-pyrroline-N-oxide (DMPO), the 2-tetrahydrofuryl or methyl radicals, deriving from the tetrahydrofuran (THF) or dimethyl sulfoxide (DMSO) solvent, respectively, were detected. For both [Pd(3)(mu(3)-CO)(dppm)(3)](2+) and [Pd(3)(mu(3)-CO)(dppm)(3)](+), the mechanism involves, in a first equilibrated step, the formation of a hydroxide adduct, [Pd(3)(mu(3)-CO)(dppm)(3)(OH)]((n-1)+) (n=1, 2), which reacts irreversibly with the solvent. The kinetics were resolved by means of stopped-flow experiments and are consistent with the proposed mechanism. In the presence of an excess of Bu(4)NOH, an electrocatalytic process was observed with modest turnover numbers (7-8). The hydroxide adducts [Pd(3)(mu(3)-CO)(dppm)(3)(OH)]((n-1)+) (n=1, 2), which bear important similarities to the well-known corresponding halide adducts [Pd(3)(mu(3)-CO)(dppm)(3)(mu(3)-X)](n) (X=Cl, Br, I), have been studied by using density functional theory (DFT). Although the optimised geometry for the cluster in its +2 and 0 oxidation states (i.e., cation and anion clusters, respectively) is the anticipated mu(3)-OH form, the paramagnetic species, [Pd(3)(mu(3)-CO)(dppm)(3)(OH)](0), shows a mu(2)-OH form; this suggests an important difference in electronic structure between these three species.

show abstract

“…+ , the mechanism involves, in a first equilibrated step, the formation of a hydroxide adduct, [Pd 3 …”

Section: -Co)a C H T U N G T R E N N U N G (Dppm) ]mentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Unexpected Reaction of the Unsaturated Cluster Host and Catalyst [Pd₃(μ³‐CO)(dppm)₃]²⁺ with the Hydroxide Ion: Spectroscopic and Kinetic Evidence of an Inner‐Sphere Mechanism

Cugnet

Lucas

Lemaître

et al. 2006

Chemistry A European J

View full text Add to dashboard Cite

show abstract

“…2), suggests that the molecule is symmetrical (i.e., type I, where one of the oxygens is triply bridging the Pd atoms). Literature data show that indeed linear molecules such as SCN-and HCECH add to the M3 centers (M = Pd, Pt) quasi-perpendicularly, when bridging in a triply bridging fashion (12).…”

Section: Photoadditionmentioning

confidence: 99%

“…The catalytic oxidation of organics by palladium and platinum metals and their coordination complexes is of great importance with regard to a number of industrial applications such as water-gas shift reaction (M = Pt) (12) and the electroreduction of CO, (M = ~d ) . ' More relevant to this work, Puddephatt and co-workers also reported the dissociative addition of dioxygen to the cationic [Pt,(dppm),(p-Re(CO),)1+ cluster to form the p3-0x0 complex [~t , ( p~-~> , (~e (~~) , ) ( d p p m ) , ] + (1 3).…”

Section: Introductionmentioning

confidence: 99%

Photoinduced addition of dioxygen molecules in the unsaturated sites of the Pd₃(dppm)₃CO²⁺ catalyst

Harvey¹,

Crozet²,

Aye³

1995

Can. J. Chem.

View full text Add to dashboard Cite

The photoinduced addition of 0, onto the unsaturated cluster Pd,(dppm),C~~+ (as a CF,CO,-salt) in acetonitrile is reported. The final product ~d , ( d~~m ) , ( O , )~ (~( 0 , ) = 838 and 866 cm-') is formed in a multistep fashion in which two photochemical intermediates are observed (presumably ~d,(dppm),(0,)(~0)~+ and ~d , ( d~~m ) , ( 0 , )~+ ) .No X-ray structure could be obtained, but numerous spectroscopic findings demonstrate that 0, binds the Pd, center as a peroxo-02, and acts as a two-electron donor that triply bridges the metal atoms (forming a 44-electron cluster). The very small excited state lifetimes (between 25 and 35 ? 10 ps) obtained by picosecond flash photolysis indicate that the primary photoreaction is unimolecular, and demonstrate that the first photochemically added 0, molecule must be preassembled in the excited state prior to any photoinduced transformation. This ~d , ( d~~m ) , C 0~+ . . . 0 , ground state complex is responsible for the photoinduced production of the bisdioxygen compound and can be observed by UV-visible spectroscopy. The low efficiency of the photoreaction (quantum yield (0) = 0.033 ? 0.004) is explained by the very short excited state lifetime at 298 K, and the competition of 0, with solvent molecules to occupy the unsaturated site of the empty cavity in ~d , ( d~~m ) ,~0~+ (i.e., ground state guest-host chemistry). The binding constant for 0, with ~d , ( d~~m ) ,~0~+ is roughly estimated to range between 1 and 730 M-I in the ground state and is considered to be weak.

show abstract

Formation of Triangular Arrays

Balch¹

1998

Inorganic Reactions and Methods

View full text Add to dashboard Cite

Coordinatively unsaturated tripalladium and triplatinum clusters: Models for reactions on metal surfaces

Cited by 138 publications

References 103 publications

Unexpected Reaction of the Unsaturated Cluster Host and Catalyst [Pd₃(μ³‐CO)(dppm)₃]²⁺ with the Hydroxide Ion: Spectroscopic and Kinetic Evidence of an Inner‐Sphere Mechanism

Unexpected Reaction of the Unsaturated Cluster Host and Catalyst [Pd₃(μ³‐CO)(dppm)₃]²⁺ with the Hydroxide Ion: Spectroscopic and Kinetic Evidence of an Inner‐Sphere Mechanism

Photoinduced addition of dioxygen molecules in the unsaturated sites of the Pd₃(dppm)₃CO²⁺ catalyst

Formation of Triangular Arrays

Contact Info

Product

Resources

About

Coordinatively unsaturated tripalladium and triplatinum clusters: Models for reactions on metal surfaces

Cited by 138 publications

References 103 publications

Unexpected Reaction of the Unsaturated Cluster Host and Catalyst [Pd3(μ3‐CO)(dppm)3]2+ with the Hydroxide Ion: Spectroscopic and Kinetic Evidence of an Inner‐Sphere Mechanism

Unexpected Reaction of the Unsaturated Cluster Host and Catalyst [Pd3(μ3‐CO)(dppm)3]2+ with the Hydroxide Ion: Spectroscopic and Kinetic Evidence of an Inner‐Sphere Mechanism

Photoinduced addition of dioxygen molecules in the unsaturated sites of the Pd3(dppm)3CO2+ catalyst

Formation of Triangular Arrays

Contact Info

Product

Resources

About

Unexpected Reaction of the Unsaturated Cluster Host and Catalyst [Pd₃(μ³‐CO)(dppm)₃]²⁺ with the Hydroxide Ion: Spectroscopic and Kinetic Evidence of an Inner‐Sphere Mechanism

Unexpected Reaction of the Unsaturated Cluster Host and Catalyst [Pd₃(μ³‐CO)(dppm)₃]²⁺ with the Hydroxide Ion: Spectroscopic and Kinetic Evidence of an Inner‐Sphere Mechanism

Photoinduced addition of dioxygen molecules in the unsaturated sites of the Pd₃(dppm)₃CO²⁺ catalyst