Immobilization of molecular catalysts on solid supports <i>via</i> atomic layer deposition for chemical synthesis in sustainable solvents

Ayare, Pooja J.; Gregory, Shawn A.; Key, Ryan J.; Short, Andrew E.; Tillou, Jake G.; Sitter, James D.; Yom, Typher; Goodlett, Dustin W.; Lee, Dong‐Chan; Alamgir, Faisal M.; Losego, Mark D.; Vannucci, Aaron K.

doi:10.1039/d1gc02024b

Cited by 10 publications

(3 citation statements)

References 63 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…With the information accumulated from previous experiments, attempts were made to reduce the catalyst loading to achieve higher TONs. Frequently, reduced catalyst concentration leads to higher TON values due to reduced decomposition events involving catalyst–catalyst interactions. , Reactions were run both with and without base to get the highest TON for the best catalyst, namely 2 6OH . With 5 × 10 –5 mol % of 2 6OH and 0.5 mol % Na 2 CO 3 , nearly a 997,000 TON was achieved for the HDO reaction on vanillyl alcohol in 20 h. For certain substrates, base-free conditions are desirable, and this reaction can be run base free with 1 × 10 –4 mol % of 2 6OH yielding 836,000 TON in 20 h. Thus, high TON values can be achieved under base-free conditions, but typically, a higher catalyst loading is required.…”

Section: Resultsmentioning

confidence: 99%

Iridium Dihydroxybipyridine Complexes are Effective Catalysts for Hydrodeoxygenation of Vanillyl Alcohol in Water

Yao,

Buell,

Kuppravalli

et al. 2023

Organometallics

Self Cite

View full text Add to dashboard Cite

The selective reduction and deoxygenation of ligninderived organic compounds are of interest for modeling a key reaction in the utilization of biomass. Toward this goal, vanillyl alcohol is used as a lignin monomer surrogate herein, and we study its reduction to form creosol in an aqueous solution. Four water-soluble iridium catalysts of the type [Cp*Ir(OH 2 )(bpy R2 )](OTf) 2 (2 R , where Cp* = η 5 -pentamethylcyclopentadienyl anion and bpy R2 = n,n′-R 2 -2,2′-bipyridine with n = 4 or 6) with different R substituents (R = H, OH, Me) in different positions on the bipyridine ligands were studied for this hydrodeoxygenation (HDO) reaction on vanillyl alcohol. Modification of the bipyridine ligands demonstrated that a more electron-rich bpy-derived ligand (R = OH) gives a more efficient HDO reaction. The addition of base serves to further enhance the HDO reaction by deprotonating the protic OH groups (OH groups on n,n′-dihydroxybipyridine where n = 4 in 2 4OH or 6 in 2 6OH ) resulting in a more electron-rich catalyst. Proximal OH groups in 2 6OH produce our most active catalyst, and we can suggest that a metal−ligand bifunctional mechanism of H 2 activation and/or transfer to the substrate may be responsible for the greater efficiency of 2 6OH vs 2 4OH . The catalyst loading could be reduced to 5 × 10 −5 mol % of 2 6OH with 0.5 mol % Na 2 CO 3 and 997,000 turnovers (TON) could be achieved in 20 h at 100 °C. Furthermore, the same catalyst at 1 × 10 −4 mol % produces 836,000 TON under similar but base-free conditions. Such catalytic efficiency in a dilute aqueous solution is noteworthy for potential applications.

show abstract

Section: Resultsmentioning

confidence: 99%

Iridium Dihydroxybipyridine Complexes are Effective Catalysts for Hydrodeoxygenation of Vanillyl Alcohol in Water

Yao,

Buell,

Kuppravalli

et al. 2023

Organometallics

Self Cite

View full text Add to dashboard Cite

show abstract

“…On the other hand, recycling a molecular catalyst can be an arduous task. Anchoring a molecular catalyst on a chemically inert surface − is a way to overcome this hurdle.…”

Section: Introductionmentioning

confidence: 99%

Potential of Molecular Catalysts with Electron-Rich Transition Metal Centers for Addressing Long-Standing Chemistry Enigmas

Androutsopoulos,

Sader,

Miliordos

2024

J. Phys. Chem. A

View full text Add to dashboard Cite

Molecular complexes with electron-rich metal centers are highlighted as potential catalysts for the following five important chemical transformations: selective conversion of methane to methanol, capture and utilization of carbon dioxide, fixation of molecular nitrogen, water splitting, and recycling of perfluorochemicals. Our initial focus lies on negatively charged metal centers and ligands that can stabilize anionic metal atoms. Catalysts with electron-rich metal atoms (CERMAs) can sustain catalytic cycles with a “ping-pong” mechanism, where one or more electrons are transferred from the metal center to the substrate and back. The donated electrons can activate the chemical bonds of the substrate by populating its antibonding orbitals. At the last step of the catalytic cycle, the electrons return to the metal and the product interacts only weakly with the formed anion, which enables the solvent molecules to remove the product fast from the catalytic cycle and prevent subsequent unfavorable reactions. This process resembles electrocatalysis, but the metal serves as both an anode and a cathode (molecular electrocatalysis). We also analyze the usage of CERMAs as the base of Frustrated Lewis pairs proposing a new type of bimetallic catalysts. This Featured Article aspires to initiate systematic experimental and theoretical studies on CERMAs and their reactivity, the potential of which has probably been underestimated in the literature.

show abstract

“…Previously, it has been shown that low-temperature ALD is sufficiently gentle for the growth of metal oxide layers on molecule functionalized metal oxide surfaces [ 22 , 23 ]. This results in increased stability [ 24 ], improved catalytic activity [ 25 ], inhibited lateral hole hopping [ 26 ], and enhanced solar cell performance [ 22 , 23 ]. Here we use ALD to deposit aluminum oxide (Al 2 O 3 ) on a ZrO 2 surface functionalized with phosphonated 9,10-bis(phenylethynyl)anthracene ( A in Figure 1 ) to investigate the impact of Al 2 O 3 deposition on the photophysical properties and intermolecular interactions at a dye–metal oxide interface.…”

Section: Introductionmentioning

confidence: 99%

Influence of Al2O3 Overlayers on Intermolecular Interactions between Metal Oxide Bound Molecules

Knorr,

Basquill,

Bertini

et al. 2023

Molecules

View full text Add to dashboard Cite

Intermolecular interactions on inorganic substrates can have a critical impact on the electrochemical and photophysical properties of the materials and subsequent performance in hybrid electronics. Critical to the intentional formation or inhibition of these processes is controlling interactions between molecules on a surface. In this report, we investigated the impact of surface loading and atomic-layer-deposited Al2O3 overlayers on the intermolecular interactions of a ZrO2-bound anthracene derivative as probed by the photophysical properties of the interface. While surface loading density had no impact on the absorption spectra of the films, there was an increase in excimer features with surface loading as observed by both emission and transient absorption. The addition of ALD overlayers of Al2O3 resulted in a decrease in excimer formation, but the emission and transient absorption spectra were still dominated by excimer features. These results suggest that ALD may provide a post-surface loading means of influencing such intermolecular interactions.

show abstract

Immobilization of molecular catalysts on solid supports via atomic layer deposition for chemical synthesis in sustainable solvents

Abstract: Atomic layer deposition immobilizes molecular catalysts on solid supports, which prevents molecular deactivation pathways and leads to longer catalyst lifetimes in high aqueous content solvents.

Cited by 10 publications

References 63 publications

Iridium Dihydroxybipyridine Complexes are Effective Catalysts for Hydrodeoxygenation of Vanillyl Alcohol in Water

Iridium Dihydroxybipyridine Complexes are Effective Catalysts for Hydrodeoxygenation of Vanillyl Alcohol in Water

Potential of Molecular Catalysts with Electron-Rich Transition Metal Centers for Addressing Long-Standing Chemistry Enigmas

Influence of Al2O3 Overlayers on Intermolecular Interactions between Metal Oxide Bound Molecules

Contact Info

Product

Resources

About