Surprising Differences of Alkane C‐H Activation Catalyzed by Ruthenium Nanoparticles: Complex Surface‐Substrate Recognition?

• Published in: ChemCatChem Vol. 10; no. 19; pp. 4243 - 4247
• Main Authors: Rothermel, Niels, Bouzouita, Donia, Röther, Tobias, de Rosal, Iker, Tricard, Simon, Poteau, Romuald, Gutmann, Torsten, Chaudret, Bruno, Limbach, Hans‐Heinrich, Buntkowsky, Gerd
• Format: Journal Article
• Language: English
• Published: Weinheim Wiley Subscription Services, Inc 09-10-2018; Wiley
• Subjects: Activation; Alkane C−H activation; Alkanes; Catalysis; Chemical Sciences; Cyclohexane; Density functional calculations; Deuteration; Deuterium isotopic labeling; Enthalpy; Nanoparticles; or physical chemistry; Organic chemistry; Ruthenium; Substrates; Theoretical and
• ISSN: 1867-3880; 1867-3899; 1867-3899
• DOI: 10.1002/cctc.201801022

The activation of C−H bonds of alkanes remains a major challenge for chemistry. In a series of deuteration experiments with D2 in contact with bis‐(diphenylphosphino) butane (dppb) stabilized ruthenium nanoparticles (liquid substrates, 60 °C, 6 bar D2) we have observed a surprisingly large reactivity of cyclopentane as compared to cyclohexane and other alkanes. DFT calculations using a ligand‐free Ru13H17 model cluster as catalyst indicate oxidative C−H cleavage of the bound substrates as rate limiting reaction step. They also indicate similar binding and activation enthalpies of reactions of cyclopentane and cyclohexane.
Lazy chair: Bis‐(diphenylphosphino) butane stabilized ruthenium nanoparticles catalyze C−H activation and deuteration of alkanes with D2 gas. Surprisingly, cyclopentane exhibits a substantially larger reactivity as compared to cyclohexane and other flexible alkanes. The effect is discussed in terms of a complex nanoparticle surface whose catalytic activity discriminates between different substrates according to their structure, similarly to substrate recognition by enzymes.