Heterodinuclear Compounds

Chetcuti, Michael J.

doi:10.1016/b978-008046519-7.00086-1

Cited by 21 publications

(8 citation statements)

References 882 publications

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“…Heterodinuclear complexes and heterobimetallic cluster complexes have attracted much attention, since they may show a synergistic effect of different metal centers on the reactivity of organic ligands such as alkyl and aryl groups . Many papers have reported the synergistic effect of two different metals in catalytic and stoichiometric transformations on the dinuclear or cluster complexes.…”

Section: Introductionmentioning

confidence: 99%

Enhancement of CO Insertion into a Pd−C Bond in a Pd−Co Heterodinuclear Complex

et al. 2001

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A series of Pd-containing heterodinuclear methyl complexes, (dppe)(CH 3 )Pd-ML n (ML n ) MoCp(CO) 3 , WCp(CO) 3 , Co(CO) 4 ; dppe ) 1,2-bis(diphenylphosphino)ethane), have been prepared by the metathetical reactions of Pd(CH 3 )(NO 3 )(dppe) with Na + [ML n ] -, and the complexes were characterized by spectroscopic methods and/or X-ray structure analysis. Related Pt-containing dinuclear complexes were similarly prepared and characterized. The rate of CO insertion into a Pd-CH 3 or Pt-CH 3 bond was investigated using these complexes. The Pd-Co complex (dppe)(CH 3 )Pd-Co(CO) 4 shows a high activity of CO insertion, giving (dppe)(CH 3 CO)Pd-Co(CO) 4 , and the initial rate is ca. 80 times higher than those of the analogous complex Pd(CH 3 )Cl(dppe). Whereas slow insertion of CO is observed in the PtCo complex (dppe)(CH 3 )Pt-Co(CO) 4 , no reaction takes place for Pt(CH 3 )Cl(dppe). It is revealed by using 13 CO that CO in the Co(CO) 4 fragment preferentially inserts into the Pd-CH 3 bond over CO in the gas phase. The carbonyl insertion reaction in the Pd-Co heterodinuclear complex has been theoretically studied using B3LYP hybrid density functional theory to clarify its reaction mechanism and the electronic factors controlling the reaction. The calculations for a model complex, (H 2 PCH 2 CH 2 PH 2 )Pd(CH 3 )-Co(CO) 4 , have shown that the most favorable reaction path consists of methyl migration from the Pd to the Co atom, carbonyl insertion reaction on the Co atom, CO coordination to the Co atom, and acetyl migration from the Co atom to the Pd atom, which is in accord with the experimental results. The electron donation from the Pd d orbital to the bridging CO π* orbitals plays an important role in stabilizing the intermediates and transition states.

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Section: Introductionmentioning

confidence: 99%

Enhancement of CO Insertion into a Pd−C Bond in a Pd−Co Heterodinuclear Complex

et al. 2001

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“…We report here on, to the best of our knowledge, the first isolated Pd 0 −1-alkyne complexes and also some new Pd 0 complexes with internal alkynes . While related Ni(0)−1-alkyne complexes are still scarce, the group of Pt(0)−1-alkyne complexes is quite broad.…”

Section: Introductionmentioning

confidence: 99%

(R₂PC₂H₄PR₂)Pd⁰−1-Alkyne Complexes

et al. 1997

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Displacement of the ethene ligand in (dippe)Pd(C2H4) (dippe = iPr2PC2H4PiPr2) by 1-alkynes RC⋮CH affords the mononuclear complexes (dippe)Pd(RC⋮CH) (R = Me (2a), Ph (3a), CO2Me (4), SiMe3 (5)). The molecular structure of 3a has been determined by X-ray crystallography. Mononuclear 2a and 3a have been reacted with stoichiometric amounts of (dippe)Pd(η1-C3H5)2 as a source for [(dippe)Pd0] to yield the dinuclear derivatives {(dippe)Pd}2(μ-RC⋮CH) (R = Me (2b), Ph (3b)). By the reaction of (dippe)Pd(C2H4) with difunctional vinylacetylene the mononuclear complex (dippe)Pd{(1,2-η2)-RC⋮CH} (R = CHCH2 (6a)) is formed, which is in equilibrium with isomeric (dippe)Pd{(3,4-η2)-H2CCHC⋮CH} (6b). Addition of [(dippe)Pd0] to 6a,b yields dinuclear {(dippe)Pd}2(μ-RC⋮CH) (R = CHCH2 (6c)). Reaction of (dippe)Pd(C2H4) with butadiyne affords (dippe)Pd(η2-HC⋮CC⋮CH) (7c). From dippe, Pt(cod)2, and C4H2 the Pt homologue has also been synthesized and thus, together with the already known Ni derivative, the series (dippe)M(η2-HC⋮CC⋮CH) (M = Ni (7a), Pd (7c), Pt (7f)) is now complete. When 7c and [(dippe)Pd0] are combined, the dinuclear complex {(dippe)Pd}2(μ-RC⋮CH) (R = C⋮CH (7e)) is formed in solution, whereas isomeric {(dippe)Pd}2{μ-(1,2-η2):(3,4-η2)-HC⋮CC⋮CH} (7d) is present in the solid state. The preparation of the Pd0−1-alkyne complexes refutes the conventional wisdom that this type of compound is inherently unstable. By reaction of (dippe)Pd(C2H4) with internal alkynes C2R2 the complexes (dippe)Pd(RC⋮CR) (R = Me (8a), Ph (9), CO2Me (10), SiMe3 (11)) have also been prepared. Combining 8a with [(dippe)Pd0] affords dinuclear {(dippe)Pd}2(μ-MeC⋮CMe) (8b). Finally, solution thermolysis of 2b and 8b gives rise to dinuclear alkyne-free Pd2(dippe)2 (12).

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“…Heterometallic complexes, by their very nature, offer at least two chemically different metallic sites, which are each susceptible to react with various ligands. The concept of metalloselectivity of a reaction then becomes essential. , The chemistry of heterobimetallic complexes and their ability to carry out hydrocarbyl transformations have led to their being the subject of extensive studies. If one of the metallic centers is coordinatively unsaturated, or potentially so, that metal is likely to be the site of reactivity.…”

Section: Introductionmentioning

confidence: 99%

Carbon−Phosphorus Bond Cleavage in Allyldiphenylphosphine by a Heterobimetallic Ni═Mo Complex and Formation of an Electronically Unsaturated NiMo₂ μ-Diphenylphosphido Cluster

et al. 2008

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The unsaturated nickel-molybdenum complex [(η-C 5 Me 5 )NidMo(CO) 3 (η-C 5 H 5 )] (NidMo), 1, reacts with allyldiphenylphosphine (ADPP) to give the complex [(η-C 5 Me 5 )Ni(µ-CO) 2 Mo(CO)(κ 1 (P)-PPh 2 CH 2 CHdCH 2 )(η-C 5 H 5 )] (Ni-Mo), 2, which is in equilibrium with the starting materials at ambient temperature. Nevertheless, orange crystals of complex 2 could be isolated from the solution, and a single-crystal X-ray diffraction study confirmed that the phosphine ligand is bound to the molybdenum atom via the phosphorus atom alone. Prolonged heating of complex 1 with excess ADPP led to activation of the P-C allyl bond and to the isolation of the unsaturated trinuclear NiMo 2 µ-diphenylphosphido cluster [(η-C 5 Me 5 )NiMo 2 (η-C 5 H 5 ) 2 (µ 3 -CO)(µ-PPh 2 )(CO) 2 ], 3. The structure of this 46-electron cluster was established spectroscopically and by a single-crystal X-ray diffraction study. It is electronically unsaturated and contains a formal ModMo double bond that is spanned by a µ-PPh 2 ligand; the molecule exhibits effective mirror plane symmetry in solution, and in the solid state, an approximate mirror plane is also observed.

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Heterodinuclear Compounds

Cited by 21 publications

References 882 publications

Enhancement of CO Insertion into a Pd−C Bond in a Pd−Co Heterodinuclear Complex

Enhancement of CO Insertion into a Pd−C Bond in a Pd−Co Heterodinuclear Complex

(R₂PC₂H₄PR₂)Pd⁰−1-Alkyne Complexes

Carbon−Phosphorus Bond Cleavage in Allyldiphenylphosphine by a Heterobimetallic Ni═Mo Complex and Formation of an Electronically Unsaturated NiMo₂ μ-Diphenylphosphido Cluster

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Heterodinuclear Compounds

Cited by 21 publications

References 882 publications

Enhancement of CO Insertion into a Pd−C Bond in a Pd−Co Heterodinuclear Complex

Enhancement of CO Insertion into a Pd−C Bond in a Pd−Co Heterodinuclear Complex

(R2PC2H4PR2)Pd0−1-Alkyne Complexes

Carbon−Phosphorus Bond Cleavage in Allyldiphenylphosphine by a Heterobimetallic Ni═Mo Complex and Formation of an Electronically Unsaturated NiMo2 μ-Diphenylphosphido Cluster

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(R₂PC₂H₄PR₂)Pd⁰−1-Alkyne Complexes

Carbon−Phosphorus Bond Cleavage in Allyldiphenylphosphine by a Heterobimetallic Ni═Mo Complex and Formation of an Electronically Unsaturated NiMo₂ μ-Diphenylphosphido Cluster