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Glycerol, a by‐product of biodiesel production, has gained prominence as a precious platform chemical. To enhance the economic viability of the biodiesel production process and address the surplus of glycerol production, it is essential to transform it into value‐added products. In this context, homogeneous catalysis offers a promising avenue for glycerol valorisation. In this study, we introduce a family of iridium complexes bearing picolineamidate ligands with glucose‐functionalised substituents as novel homogeneous catalysts for glycerol to hydrogen and lactic acid conversion. These complexes exhibit high activity (conversion up to 53.3 %) and 99 % selectivity after 24 hours of reaction (TOFMAX=159 h−1, TON24h=2498). Notably, the reaction occurs under ambient air and at milder temperature conditions (120 °C) compared to other catalysts. These efforts in glycerol valorisation contribute to reducing biodiesel production costs, increasing the competitiveness of biofuels against petroleum‐based liquid fuels, giving rise to H2, through a global process with negative carbon dioxide emission, and lactic acid utilizable, among other, as a monomer for the synthesis of biodegradable plastics. [ABSTRACT FROM AUTHOR]

[Cp*Ir(R‐pica)Cl] (Cp*=pentamethylcyclopentadienyl anion, pica=2‐picolineamidate) complexes bearing carbohydrate substituents on the amide nitrogen atom (R=methyl‐β‐D‐gluco‐pyranosid‐2‐yl, 1; methyl‐3,4,6‐tri‐O‐acetyl‐β‐D‐glucopyranosid‐2‐yl, 2) were tested as catalysts for formic acid dehydrogenation in water. TOFMAX values over 12000 h−1 and 50000 h−1 were achieved at 333 K for 1 and 2, respectively, with TON values over 35000 for both catalysts. Comparison with the simpler cyclohexyl‐substituted analogue (3) indicated that glucosyl‐based complexes are much better performing under the same experimental conditions (TOFMAX=5144 h−1, TON=5000 at pH 2.5 for 3) owing to a lower tendency to isomerize to the less active k2‐N,O isomer upon protonation. The 5‐fold increase in TOFMAX observed for 2 with respect to 1 is reasonably due to an optimal steric protection by the acetyl substituent, which may prevent unproductive inner‐sphere reactivity. These results showcase a powerful strategy for the inhibition of the common deactivation pathways of [Cp*Ir(R‐pica)X] catalysts for FA dehydrogenation, paving the way for the development of better performing hydrogen storage systems. [ABSTRACT FROM AUTHOR]

A yet‐outstanding supramolecular chemistry challenge is isolation of novel varieties of stacked complexes with finely‐tuned donor‐acceptor bonding and optoelectronic properties, as herein reported for binary adducts comprising two different cyclic trinuclear complexes (CTC@CTC'). Most previous attempts focused only on 1–2 factors among metal/ligand/substituent combinations, resulting in heterobimetallic complexes. Instead, here we show that, when all 3 factors are carefully considered, a broadened variety of CTC@CTC' stacked pairs with intuitively‐enhanced intertrimer coordinate‐covalent bonding strength and ligand‐ligand/metal‐ligand dispersion are attained (dM–M' 2.868(2) Å; ΔE>50 kcal/mol, an order of magnitude higher than aurophilic/metallophilic interactions). Significantly, CTC@CTC' pairs remain intact/strongly‐bound even in solution (Keq 4.67×105 L/mol via NMR/UV‐vis titrations), and the gas phase (mass spectrometry revealing molecular peaks for the entire CTC@CTC' units in sublimed samples), rather than simple co‐crystal formation. Photo‐/electro‐luminescence studies unravel metal‐centered phosphorescence useful for novel all metal‐organic light‐emitting diodes (MOLEDs) optoelectronic device concepts. This work manifests systematic design of supramolecular bonding and multi‐faceted spectral properties of pure metal‐organic macrometallacyclic donor/acceptor (inorganic/inorganic) stacks with remarkably‐rich optoelectronic properties akin to well‐established organic/organic and organic/inorganic analogues. [ABSTRACT FROM AUTHOR]

Manganese‐catalyzed hydrogenation reactions have aroused widespread interest in recent years. Among the catalytic systems described, especially PNP‐ and NNP–Mn pincer catalysts have been reported for the hydrogenation of aldehydes, ketones, nitriles, aldimines and esters. Furthermore, NNP−Mn pincer compounds are efficient catalysts for the hydrogenolysis of less reactive amides, ureas, carbonates, and carbamates. Herein, the synthesis and application of specific imidazolylaminophosphine ligands and the corresponding Mn pincer complexes are described. These new catalysts have been characterized and studied by a combination of experimental and theoretical investigations, and their catalytic activities have been tested in several hydrogenation reactions with good to excellent performance. Especially, the reduction of N‐heterocycles can be performed under very mild conditions. [ABSTRACT FROM AUTHOR]

This article discusses a new class of binary adducts that are composed of two different cyclic trinuclear complexes (CTC@CTC'). These adducts have enhanced bonding strength and remain intact even in solution or the gas phase. They also exhibit remarkable RGB luminescence when exposed to electromagnetic irradiation or electric drive voltage. The research article provides more information on this topic and includes artwork by Danah M. Omary and Lorenzo Luciani. [Extracted from the article]

The development of an efficient heterogeneous catalyst for storing H 2 into CO 2 and releasing it from the produced formic acid, when needed, is a crucial target for overcoming some intrinsic criticalities of green hydrogen exploitation, such as high flammability, low density, and handling. Herein, we report an efficient heterogeneous catalyst for both reactions prepared by immobilizing a molecular iridium organometallic catalyst onto a high-surface mesoporous silica, through a sol-gel methodology. The presence of tailored single-metal catalytic sites, derived by a suitable choice of ligands with desired steric and electronic characteristics, in combination with optimized support features, makes the immobilized catalyst highly active. Furthermore, the information derived from multinuclear DNP-enhanced NMR spectroscopy, elemental analysis, and Ir L 3 -edge XAS indicates the formation of cationic iridium sites. It is quite remarkable to note that the immobilized catalyst shows essentially the same catalytic activity as its molecular analogue in the hydrogenation of CO 2 . In the reverse reaction of HCOOH dehydrogenation, it is approximately twice less active but has no induction period.