New insights for valorization of polyolefins/light alkanes: catalytic dehydrogenation of n-alkanes by immobilized pincer-iridium complexes

This scientific review delves into the innovative realm of polyolefins/light alkanes valorization through their catalytic dehydrogenation employing pincer-ligated iridium organometallic complexes. These widely studied catalysts exhibit outstanding properties, although the intrinsic characteristics of homogeneous catalysis (such as challenging product-catalyst separation, poor applicability to continuous-flow processes and low recyclability) limit their activity and industrial application, as well as their thermal stability. Through the immobilization of complexes on inorganic supports, these downsides have been bypassed, harnessing the true potential of these catalysts, affording more selective and stable catalysts in addition to facilitating their implementation in industrial processes. The findings described herein contribute to the advancement in the understanding of catalytic processes in hydrocarbon transformations, offering promising avenues for sustainable and selective production of valuable chemical intermediates from readily available feedstocks.

Immobilization of an Iridium Pincer Complex in a Microporous Polymer for Application in Room-Temperature Gas Phase Catalysis

An iridium dihydride pincer complex [IrH2 (POCOP)] is immobilized in a hydroxy-functionalized microporous polymer network using the concepts of surface organometallic chemistry. The introduction of this novel, truly innocent support with remote OH-groups enables the formation of isolated active metal sites embedded in a chemically robust and highly inert environment. The catalyst maintained high porosity and without prior activation exhibited efficacy in the gas phase hydrogenation of ethene and propene at room temperature and low pressure. The catalyst can be recycled for at least four times.

A metal-organic framework immobilised iridium pincer complex

An iridium pincer complex has been immobilised in the metal-organic framework NU-1000 using a technique called solvent assisted ligand-incorporation (SALI). The framework proved to be stable under the conditions required to activate the iridium complex and spectroscopic investigations showed formation of the catalytically active iridium dihydride. The Ir-pincer modified NU-1000 is an active catalyst for the condensed phase hydrogenation of a liquid alkene (1-decene and styrene) and shows enhanced activity with respect to a homogeneous analogue. Additionally, the Ir-pincer immobilised inside NU-1000 operated as an efficient heterogenous catalyst under flow conditions.

Magnetic nanoparticle-supported ferrocenylphosphine: a reusable catalyst for hydroformylation of alkene and Mizoroki–Heck olefination

This study was focused on regioselective, re-usable and solvent-free catalysis using Fe3O4@dop-BPPF nanomaterials.