Jump to content

Draft:Cocktail-Type Catalysis

From Wikipedia, the free encyclopedia


Cocktail-type catalysis is a concept in chemistry where multiple types of metal catalysts coexist and contribute to a chemical reaction through diverse pathways.[1] Unlike traditional catalytic systems that rely on a single defined catalyst, cocktail-type catalysis involves a dynamic mixture of catalytic species—such as molecular metal complexes, metal clusters, and nanoparticles—that can interconvert and adapt during the reaction.[2] This approach enhances reaction efficiency, universality, and substrate scope, making it valuable in fields such as organic synthesis, sustainable processes and green chemistry.

The concept of cocktail-type catalysis for transition metal catalysts was first encountered by Ananikov and co-workers in 2012 in a mechanistic study of Pd-catalyzed reactions.[3] This work proposed that many catalytic systems in solution involve more than one active species, leading to the description of these systems as “cocktails” of catalysts, where multiple catalytic pathways operate in parallel.

Overview

[edit]

In traditional catalysis, a single catalyst is chosen to facilitate a chemical reaction, either a metal complex in homogeneous catalysis[4][5] or nanoparticles in heterogeneous catalysis.[6][7] In contrast, cocktail-type catalysis represents a more dynamic approach where multiple catalysts or catalytic species can work together or switch roles during the reaction.[1] This adaptive behavior allows the system to self-regulate and respond to changing conditions, resulting in greater efficiency and versatility.

The concept is particularly useful in complex reactions that require high efficiency and universality, such as those used in the synthesis of organic product and advanced materials.

History

[edit]

Manifestations of cocktail-type catalysis appeared in the studies of metal-catalyzed cross-coupling reactions, such as the Suzuki and Heck reactions. Research in this area has shown that the catalyst is often split into multiple metal forms during the reaction, ranging from single metal atoms to metal clusters and nanoparticles. Transformations of catalytic species was noted in several metal-catalyzed reactions.[8][9][10][11] The transformation of metal complexes into different forms is often considered as catalyst degradation.

In 2012, Ananikov formally introduced the concept of cocktail-type catalysis, highlighting that the dynamic nature of these catalytic systems plays a crucial role in their performance.[3][12] This research challenged the traditional view that only a single catalyst type is involved in a reaction, emphasizing instead the importance of multiple, interacting species​. In the cocktail-type catalysis concept, the transformation of metal complexes into different forms is not degradation or side-reaction, but an advantageous feature of catalysis.

Mechanistic Aspects

[edit]

Cocktail-type catalysis involves the coexistence and interconversion of various catalytic species, which can include:

·    Mononuclear Metal Complexes: Traditional molecular catalysts with a single metal center and ligands.[4][5]

·    Metal Clusters: Small aggregates of metal atoms that exhibit unique catalytic properties; the number at metal atoms may be in the range of 2 – 32, but may vary depending on a system and conditions.[13]

·    Nanoparticles: Larger assemblies of metal atoms that act as reservoirs for active species; the sizes are typically in the range of 1 – 20 nm, but may be also up to 50-100 nm.[9][10]

·    Leached Metal Species: Metal atoms or clusters that detach from nanoparticles and participate in solution-phase reactions; may contain coordinated ligands, solvent or reaction components.[14]

Pathways and Dynamics

[edit]

During the reaction, these catalytic species can interconvert significantly. For example, in a typical cross-coupling reaction, nanoparticles may leach metal atoms into the solution, which then act as homogeneous catalysts. The metal atoms can later return to the particle surface or form new clusters, creating a constantly evolving "cocktail" of active species​​.

Advantages

[edit]

Cocktail-type catalysis offers several key benefits compared to traditional single-species catalysis:[1][2][9][12][13]

·    High Adaptability: Self-tuning systems that adjust to reaction conditions in real time. Universal catalysts able to catalyze several reactions or facilitating reactions for a wide range of molecules are constructed based on cocktail-type of operation.

·    Increased Efficiency: Higher reaction rates and product yields. Continuous active centers generation from a catalyst pre-cursor or reservoir ensures keeping catalytic system active for longer time even at harsh reaction conditions at high temperature.

·    Broader Substrate Scope: Tolerance for a different range of functional groups and reaction conditions. In the mixture (cocktail), at least one of the components will be able to catalyze the reaction for the molecules with a given combination of functional groups. Thus, cocktail-type catalysts are generally more likely to promote the reactions as compared to regular single-type active centers.

·    Sustainability: Reduces waste and enables catalyst recycling in certain cases. Coktail-type catalysis can be initiated from virtually any source of metal, even from a bulk metal,[15] thus reducing the number of steps needed for catalyst preparation.

Challenges

[edit]

Despite its advantages, cocktail-type catalysis presents some challenges:

·    Complex Mechanistic Analysis: Understanding the exact contribution of each catalytic species requires advanced analytical techniques and complex models.

·    Trace Metal Contamination:[16][17] Metal leaching can lead to contamination of the final product, which is a concern in trace-metal-sensitive applications.

See Also

[edit]

·    Catalysis

·    Homogeneous catalysis

·    Heterogeneous catalysis

·    Cross-Coupling Reactions

·    Nanoparticles

·    Suzuki Reaction

·    Heck reaction

References

[edit]
  1. ^ a b c Prima, Darya O.; Kulikovskaya, Natalia S.; Galushko, Alexey S.; Mironenko, Roman M.; Ananikov, Valentine P. (October 2021). "Transition metal 'cocktail'-type catalysis". Current Opinion in Green and Sustainable Chemistry. 31: 100502. Bibcode:2021COGSC..3100502P. doi:10.1016/j.cogsc.2021.100502.
  2. ^ a b Eremin, Dmitry B.; Ananikov, Valentine P. (September 2017). "Understanding active species in catalytic transformations: From molecular catalysis to nanoparticles, leaching, "Cocktails" of catalysts and dynamic systems". Coordination Chemistry Reviews. 346: 2–19. doi:10.1016/j.ccr.2016.12.021.
  3. ^ a b Zalesskiy, Sergey S.; Ananikov, Valentine P. (2012-03-26). "Pd2(dba)3 as a Precursor of Soluble Metal Complexes and Nanoparticles: Determination of Palladium Active Species for Catalysis and Synthesis". Organometallics. 31 (6): 2302–2309. doi:10.1021/om201217r. ISSN 0276-7333.
  4. ^ a b Hartwig, John Frederick (2010). Organotransition metal chemistry: from bonding to catalysis. Sausalito (Calif.): University science books. ISBN 978-1-891389-53-5.
  5. ^ a b van Leeuwen, Piet W. N. M. (2004). Homogeneous Catalysis: Understanding the Art. Dordrecht: Springer Netherlands. doi:10.1007/1-4020-2000-7. ISBN 978-1-4020-3176-2.
  6. ^ Somorjai, Gabor A.; Li, Yimin (2010). Introduction to surface chemistry and catalysis (2nd ed.). Hoboken, N.J: Wiley. ISBN 978-0-470-50823-7. OCLC 436358426.
  7. ^ Ertl, Gerhard; Knözinger, Helmut; Schüth, Ferdi; Weitkamp, Jens, eds. (2008-03-15). Handbook of Heterogeneous Catalysis: Online (1 ed.). Wiley. doi:10.1002/9783527610044. ISBN 978-3-527-31241-2.
  8. ^ Phan, Nam T. S.; Van Der Sluys, Matthew; Jones, Christopher W. (April 2006). "On the Nature of the Active Species in Palladium Catalyzed Mizoroki–Heck and Suzuki–Miyaura Couplings – Homogeneous or Heterogeneous Catalysis, A Critical Review". Advanced Synthesis & Catalysis. 348 (6): 609–679. doi:10.1002/adsc.200505473. ISSN 1615-4150.
  9. ^ a b c Trzeciak, A.M.; Augustyniak, A.W. (April 2019). "The role of palladium nanoparticles in catalytic C–C cross-coupling reactions". Coordination Chemistry Reviews. 384: 1–20. doi:10.1016/j.ccr.2019.01.008.
  10. ^ a b Liu, Lichen; Corma, Avelino (2018-05-23). "Metal Catalysts for Heterogeneous Catalysis: From Single Atoms to Nanoclusters and Nanoparticles". Chemical Reviews. 118 (10): 4981–5079. doi:10.1021/acs.chemrev.7b00776. ISSN 0009-2665. PMC 6061779. PMID 29658707.
  11. ^ Widegren, Jason A.; Finke, Richard G. (May 2003). "A review of the problem of distinguishing true homogeneous catalysis from soluble or other metal-particle heterogeneous catalysis under reducing conditions". Journal of Molecular Catalysis A: Chemical. 198 (1–2): 317–341. doi:10.1016/S1381-1169(02)00728-8.
  12. ^ a b Ananikov, Valentine P.; Beletskaya, Irina P. (2012-03-12). "Toward the Ideal Catalyst: From Atomic Centers to a "Cocktail" of Catalysts". Organometallics. 31 (5): 1595–1604. doi:10.1021/om201120n. ISSN 0276-7333.
  13. ^ a b Leyva-Pérez, A. (2017). "Sub-nanometre metal clusters for catalytic carbon–carbon and carbon–heteroatom cross-coupling reactions". Dalton Transactions. 46 (46): 15987–15990. doi:10.1039/C7DT03203J. hdl:10251/154122. ISSN 1477-9226. PMID 29063083.
  14. ^ Gnad, Christoph; Abram, Andrea; Urstöger, Alexander; Weigl, Florian; Schuster, Michael; Köhler, Klaus (2020-06-05). "Leaching Mechanism of Different Palladium Surface Species in Heck Reactions of Aryl Bromides and Chlorides". ACS Catalysis. 10 (11): 6030–6041. doi:10.1021/acscatal.0c01166. ISSN 2155-5435.
  15. ^ Samoylenko, Dmirtiy E.; Lotsman, Kristina A.; Rodygin, Konstantin S.; Ananikov, Valentin P. (2025-02-20). "Rapid and Sustainable Electrochemical Pd Catalyst Generation from Bulk Metal". Chemistry – A European Journal. 31 (11). doi:10.1002/chem.202403872. ISSN 0947-6539.
  16. ^ "Hidden flaws in common piece of lab kit could botch experiments". Nature. 568 (7751): 146. 2019-04-11. Bibcode:2019Natur.568Q.146.. doi:10.1038/d41586-019-00980-7. ISSN 0028-0836.
  17. ^ "Stir bar contamination may inadvertently catalyze reactions". Chemical & Engineering News. Retrieved 2025-04-04.
[edit]

·    Nano Nuisance For Palladium Source

·    Chemists find that metal atoms play key role in fine organic synthesis

·    Warnings that dirty stirrer bars can act as phantom catalysts

Retrieved from "https://en.wikipedia.org/w/index.php?title=Draft:Cocktail-Type_Catalysis&oldid=1283886449"