Heterogeneous self-supported organometallic nanocatalysts (ONs) were synthesized by treatment of the eta6-pi-hydroquinone rhodium complex [(1,4-hydroquinone)Rh(COD)]+ with Al(Oi-Pr)3. The organometallic nanocatalysts, the size of which can be controlled by alteration of the reaction conditions, show high catalytic activities in the stereoselective polymerization of phenylacetylene to produce cis-poly(phenylacetylene). A key feature of the ON catalyst synthesis is a facile eta6 to eta4 hapticity change occurring in the quinonoid ring, which is triggered by deprotonation of the -OH groups by Al(Oi-Pr)3, with concomitant coordination of the quinone oxygen atoms to the aluminum.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/ja062907o | DOI Listing |
Acc Chem Res
October 2024
Organometallics & Smart Materials Laboratory, Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal 462 066, India.
ConspectusThe reductive conversion of carbon dioxide (CO) into value-added products is a process of immense importance. In the context of rising CO concentration in the atmosphere and the detrimental effects it is having on the biosphere, use of alternative fuels which can offer a low-carbon or carbon-neutral pathway for storage and utilization of low-carbon energy by maintaining the net atmospheric CO concentration might be a prospective solution. Among the wide variety of reduced products that can be obtained from CO, formic acid and formate salts are particularly important due to their ability to be used as an alternative fuel or a reversible hydrogen storage material.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
December 2023
Organometallics & Smart Materials Laboratory, Department of Chemistry, Indian Institute of Science Education and Research (IISER) Bhopal, Bhopal, 462066, Madhya Pradesh, India.
In recent times, heterogenization of homogeneous molecular catalysts onto various porous solid support structures has attracted significant research focus as a method for combining the advantages of both homogeneous as well as heterogeneous catalysis. The design of highly efficient, structurally robust and reusable heterogenized single-site catalysts for the CO hydrogenation reaction is a critical challenge that needs to be accomplished to implement a sustainable and practical CO -looped renewable energy cycle. This study demonstrated a heterogenized catalyst [Ir-HCP-(B/TPM)] containing a molecular Ir-abnormal N-heterocyclic carbene (Ir-aNHC) catalyst self-supported by hierarchical porous hyper-crosslinked polymer (HCP), in catalytic hydrogenation of CO to inorganic formate (HCO ) salt that is a prospective candidate for direct formate fuel cells (DFFC).
View Article and Find Full Text PDFChem Commun (Camb)
October 2021
Organometallics & Smart Materials Laboratory, Department of Chemistry, Indian Institute of Science Education and Research (IISER) Bhopal, Bhopal 462 066, India.
Three-dimensionally propagated imidazolium-containing mesoporous coordination polymer and organic polymer-based platforms were successfully exploited to develop single-site heterogenized Pd-NHC catalysts for oxidative arene/heteroarene C-H functionalization reactions. The catalysts were efficient in directed arene halogenation, and nondirected arene and heteroarene arylation reactions. High catalytic activity, excellent heterogeneity and recyclability were offered by these systems making them promising candidates in the area of heterogeneous C-H functionalization, where efficient catalysts are still scarce.
View Article and Find Full Text PDFAngew Chem Int Ed Engl
August 2020
Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials, Department of Chemistry, Fudan University, 2005 Songhu Road, Shanghai, 200438, China.
The global demand for lactic acid (LA) is increasing due to its successful application as monomer for the manufacture of bioplastics. Although N-heterocyclic carbene (NHC) iridium complexes are promising molecular catalysts for LA synthesis, their instabilities have hindered their utilization especially in commercial applications. Here, we report that a porous self-supported NHC-iridium coordination polymer can efficiently prevent the clusterization of corresponding NHC-Ir molecules and can function as a solid molecular recyclable catalyst for dehydrogenation of bio-polyols to form LA with excellent activity (97 %) and selectivity (>99 %).
View Article and Find Full Text PDFChem Commun (Camb)
March 2017
Organometallics and Smart Materials Laboratory, Indian Institute of Science Education and Research Bhopal, Bhopal 462 066, India.
In this work, we report a single-site, heterogeneous Pd(ii)-NHC-based oxidative C-H activation catalyst, designed on a self-supported coordination polymer platform. The system has been applied successfully for selective arene C-H monohalogenation reactions affording a good degree of efficiency and reusability. Control experiments suggested that the Ru(ii)-terpyridine-based coordination network scaffolding the covalently attached Pd(ii)-NHC catalytic centres was highly robust under oxidizing conditions and rendered superior activity than the homogeneous counterpart.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!