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The novel hetero‐dinuclear complex trans,trans,trans‐[PtIV(py)2(N3)2(OH)(μ‐OOCCH2CH2CONHCH2‐bpyMe)IrIII(ppy)2]Cl (Pt‐Ir), exhibits charge transfer between the acceptor photochemotherapeutic Pt(IV) (Pt‐OH) and donor photodynamic Ir(III) (Ir‐NH2) fragments. It is stable in the dark, but undergoes photodecomposition more rapidly than the Pt(IV) parent complex (Pt‐OH) to generate Pt(II) species, an azidyl radical and 1O2. The Ir(III)* excited state, formed after irradiation, can oxidise NADH to NAD⋅ radicals and NAD+. Pt‐Ir is highly photocytotoxic towards cancer cells with a high photocytotoxicity index upon irradiation with blue light (465 nm, 4.8 mW/cm2), even with short light‐exposure times (10–60 min). In contrast, the mononuclear Pt‐OH and Ir‐NH2 subunits and their simple mixture are much less potent. Cellular Pt accumulation was higher for Pt‐Ir compared to Pt‐OH. Irradiation of Pt‐Ir in cancer cells damages nuclei and releases chromosomes. Synchrotron‐XRF revealed ca. 4× higher levels of intracellular platinum compared to iridium in Pt‐Ir treated cells under dark conditions. Luminescent Pt‐Ir distributes over the whole cell and generates ROS and 1O2 within 1 h of irradiation. Iridium localises strongly in small compartments, suggestive of complex cleavage and excretion via recycling vesicles (e.g. lysosomes). The combination of PDT and PACT motifs in one molecule, provides Pt‐Ir with a novel strategy for multimodal phototherapy. [ABSTRACT FROM AUTHOR]

Three different iridium(III) complexes, labelled as Ir1–Ir3, each bearing a unique anchoring moiety (diethyl [2,2′-bipyridine]-4,4′-dicarboxylate, tetraethyl [2,2′-bipyridine]-4,4′-diylbis(phosphonate), or [2,2′-biquinoline]-4,4′-dicarboxylic acid), were synthesized to serve as photosensitizers. Their electrochemical and photophysical characteristics were systematically investigated. ERP measurements were employed to elucidate the impact of the anchoring groups on the photocatalytic hydrogen generation performance of the complexes. The novel iridium(III) complexes were integrated with platinized TiO2 (Pt–TiO2) nanoparticles and tested for their ability to catalyze hydrogen production under visible light. A H2 turnover number (TON) of up to 3670 was obtained upon irradiation for 120 h. The complexes with tetraethyl [2,2′-bipyridine]-4,4′-diylbis(phosphonate) anchoring groups were found to outperform those bearing other moieties, which may be one of the important steps in the development of high-efficiency iridium(III) photosensitizers for hydrogen generation by water splitting. Additionally, toxicological analyses found no significant difference in the toxicity to luminescent bacteria of any of the present iridium(III) complexes compared with that of TiO2, which implies that the complexes investigated in this study do not pose a high risk to the aquatic environment compared to TiO2. [ABSTRACT FROM AUTHOR]

A series of iridium(III) triimine complexes incorporating 2,2′:6′,2″-terpyridine (terpy) and 2,6-bis(thiazol-2-yl)pyridine (dtpy) derivatives were successfully designed and synthesized to investigate the impact of the peripheral rings (pyridine, thiazole) and substituents (thiophene, bithiophene, EDOT) attached to the triimine skeleton on their photophysical properties. The Ir(III) complexes were fully characterized using IR, 1H, elemental analysis and single crystal X-ray analysis. Their thermal properties were evaluated using TGA measurements. Photoluminescence spectra of [IrCl3L1–6] were investigated in solution at 298 and 77 K. The experimental studies were accompanied by DFT/TDDFT calculations. The photophysical properties of the synthesized triimine ligands and Ir(III) complexes were studied in detail by electronic absorption and emission. In solution, they exhibited photoluminescence quantum yields ranging from 1.27% to 5.30% depending on the chemical structure. The experimental research included DFT/TDDFT calculations. The photophysical properties of the synthesized triimine ligands and Ir(III) complexes were conducted using electronic absorption and emission techniques. In solution, they displayed photoluminescence quantum yields ranging from 1.27% to 5.30% depending on the chemical structure. [ABSTRACT FROM AUTHOR]

Hypochlorous acid (HClO) and its ionic form (ClO−), as important components of reactive oxygen species, were produced mainly in mitochondria and participated in various biological processes, and they abnormal level could cause various diseases and threaten human health. Hence, a "turn‐on" phosphorescent probe Ir‐DAMN based on Ir (III) complex was synthesized to monitor HClO/ClO− in DMF/PBS solution and living cells. Due to isomerization of C=N bond, probe Ir‐DAMN exhibited very weak phosphorescence initially, which displayed obvious phosphorescent enhancement at 620 nm after upon addition with ClO−. Confocal bioimaging experiments implied that probe Ir‐DAMN possessed good cell membrane permeability, specific localization of mitochondria and could achieve detection of exogenous and endogenous HClO/ClO− in the living cells. [ABSTRACT FROM AUTHOR]

A new [Cp*IrClL] half‐sandwich iridium complex was successfully synthesized by coordinating an acylhydrazone ligand with [Cp*IrCl2]2, followed by comprehensive characterization using various spectroscopic and analytical techniques. Complex 3 was subjected to crystal structure analysis, revealing that the acylhydrazone ligand coordinates with the iridium through bidentate coordination involving the imidolate oxygen and imine nitrogen atoms. This interaction resulted in the formation of a pseudo‐octahedral geometry with the iridium center. The iridium complexes 1–4, which are stable in the presence of air and moisture, exhibit significant catalyst performance in the N‐alkylation reactions of hydrazides under gentle reaction conditions. This iridium complex catalyzes various types of alcohols to undergo N‐alkylation reactions with acyl hydrazides via a one‐pot method, yielding diverse N‐alkylated hydrazide derivatives. The catalyst displayed exceptional catalytic efficiency, a broad variety of substrates, and gentle reaction conditions, indicating its significant potential for industrial applications. [ABSTRACT FROM AUTHOR]

The field of asymmetric catalysis is rapidly developing and the chiral ligands play a key role in enantioselective transition‐metal catalysis. The electron‐rich chiral N‐heterocyclic carbenes (NHCs) have established themselves as a popular class of stereodirecting ancillary ligands to catalyze enantioselective organic transformations in more efficient ways. Several novel transition‐metal complexes in combination with tailored ligand design have emerged during last few decades in asymmetric catalysis. The tailor‐made NHCs can easily be accessed due to the modular synthesis of their parent azolium salt precursors. Their donor capability and the molecular shape can easily be tuned by changing substituent at N‐atom or by changing the cyclic backbone framework. This review article aims to describe the recent advances in this rapidly evolving research area of enantioselective catalysis using well‐defined transition‐metal complexes possessing chiral NHC donor ligands. [ABSTRACT FROM AUTHOR]

The ternary TaIr2B2 boride was prepared by the reaction between iridium and TaB2 powders. It was shown that a choice in favor of any crystal structure of TaIr2B2 boride using only X-ray powder diffraction analysis and single-crystal XRD is rather difficult to make. The DFT calculations were carried out to predict the energetically preferred crystal structure of TaIr2B2. The 11B solid-state NMR spectrum of TaIr2B2 was recorded for the first time. A combination of diffraction and spectroscopic methods, as well as theoretical calculations, allowed us to make clear choice in favor of the triclinic space group for the crystal structure of TaIr2B2. The Vickers microhardness value for TaIr2B2 was found to be 17.9 ± 2.3 GPa, and the ternary TaIr2B2 boride can be considered a hard material. Therefore, the family of hard ternary boride phases got a new member. The coefficients of thermal expansion of TaIr2B2 measured by in situ high-temperature XRD analysis are independent of temperature along the a and b axes, but the CTE along the c axis deviates noticeably at elevated temperatures. The findings for the new ternary TaIr2B2 boride are of interest for the rational design of complex structural materials containing Ta–Ir–B-based components and prediction of their high-temperature behavior. Further research into this ternary boride as well as other iridium-containing ternary borides will provide a tool to solve the problems faced by high-temperature materials science. [ABSTRACT FROM AUTHOR]

A metallacyclic maltol-tethered organometallic Ir(III) half-sandwich complex was synthesized as an analog of the ruthenium anticancer complexes (RAPTA/RAED) to evaluate its in vitro antiproliferative activity against various human cancer cell lines. [ABSTRACT FROM AUTHOR]

We successfully developed a lanthanum (La)-doped Pb (Zr,Ti)O3 (PLZT) based ferroelectric capacitor (FC) using a new electrode material of bismuth (Bi) doped SrRuO3 (B-SRO) aiming at reduction of energy consumption of ferroelectric random access memory (FeRAM) by suppressing the leakage current of its FC. Our employed B-SRO layer is effective for suppressing the leakage current due to reducing atomic interdiffusions of Iridium and lead between IrOx top electrode (TE) and PLZT. Space charge limited conduction (SCLC) is dominant in the leakage current of the FC with B-SRO, while defect assisted conduction possibly includes in the leakage current of FC without B-SRO in addition with the SCLC. Switchable polarization, depending on the B-SRO thickness, has largest value for 1.0-1.5 nm thick B-SRO. Excellent imprint and switching (fatigue) endurances is proven on the FC with 1 nm thick BSRO. [ABSTRACT FROM AUTHOR]

The development of effective and stable electrocatalysts for the hydrogen evolution reaction (HER) in acidic electrolytes is a significant challenge. In this work, homogeneous Pt nanodendrites (Pt NDs) with a PtIr shell were successfully synthesized by a two-step wet chemical method. This open three-dimensional (3D) dendritic structure exhibited exceptional electrocatalytic characteristics, exposing as many active sites as feasible. Furthermore, by alloying Ir with Pt on the surface, catalytic activity was greatly enhanced while ensuring extremely high stability. Iridium surface-enriched platinum nanodendritic catalysts (Pt@PtIr NDs) outperformed the control samples and the commercial catalysts. In acidic HER test, Pt@PtIr NDs had a lower overpotential (22 mV) than Pt NDs (26 mV) and commercial Pt/C (31 mV) at 10 mA/cm2, and the activity of Pt@PtIr NDs remained consistent even after undergoing a continuous durability test for at least 168 h, which was much superior to the performance of commercial Pt/C (10 h) under identical test conditions. This study revealed that the application of 3D Pt dendritic metal alloys may offer a chance for the development of enhanced electrocatalysts in acidic HER. [ABSTRACT FROM AUTHOR]

Abstract Three novel asymmetric Ir(III) complexes have been rationally designed to optimize their emitting dipole orientations (EDO) and enhance light outcoupling in blue phosphorescent organic light‐emitting diodes (OLEDs), thereby boosting their external quantum efficiency (EQE). Bulky electron‐donating groups (EDGs), namely: carbazole (Cz), di‐tert‐butyl carbazole (tBuCz), and phenoxazine (Pxz) are incorporated into the tridentate dicarbene pincer chelate to induce high degree of packing anisotropy, simultaneously enhancing their photophysical properties. Angle‐dependent photoluminescence (ADPL) measurements indicate increased horizontal transition dipole ratios of 0.89 and 0.90 for the Ir(III) complexes Cz‐dfppy‐CN and tBuCz‐dfppy‐CN, respectively. Analysis of the single crystal structure and density functional theory (DFT) calculation results revealed an inherent correlation between molecular aspect ratio and EDO. Utilizing the newly obtained emitters, the blue OLED devices demonstrated exceptional performance, achieving a maximum EQE of 30.7% at a Commission International de l'Eclairage (CIE) coordinate of (0.140, 0.148). Optical transfer matrix‐based simulations confirmed a maximum outcoupling efficiency of 35% due to improved EDO. Finally, the tandem OLED and hyper‐OLED devices exhibited a maximum EQE of 44.2% and 31.6%, respectively, together with good device stability. This rational molecular design provides straightforward guidelines to reach highly efficient and stable saturated blue emission.

The title compound, [Ir(C15H10N)2(C19H12N4)]PF6·CH3OH, crystallizes in the C2/c space group with one monocationic iridium complex, one hexafluoridophosphate anion, and one methanol solvent molecule of crystallization in the asymmetric unit, all in general positions. The anion and solvent are linked to the iridium complex cation via hydrogen bonding. All bond lengths and angles fall into expected ranges compared to similar compounds.

A new triazole-based N-heterocyclic carbene IrI cationic complex with a tetrafluoridoborate counter-anion and hemi-solvating dichloromethane, [Ir(C8H12)(C8H15N3)(C18H15P)]BF4·0.5CH2Cl2, has been synthesized and structurally characterized. There are two independent ion pairs in the asymmetric unit and one dichloromethane solvent molecule per two ion pairs. The cationic complex exhibits a distorted square-planar conformation around the IrI atom, formed by a bidentate cycloocta-1,5,diene (COD) ligand, a triphenylphosphane ligand, and an N-heterocyclic carbene (NHC). There are several close non-standard H...F hydrogen-bonding interactions that orient the tetrafluoridoborate anions with respect to the IrI complex molecules. The complex shows promising catalytic activity in transfer hydrogenation reactions. The structure was refined as a non-merohedral twin, and one of the COD molecules is statistically disordered.

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Mass spectrometric analysis of anionic products that result from interacting Ir− with H2O shows the efficient generation of [Ir(H2O)]− complexes and IrO− molecular anions. Anion photoelectron spectra of [Ir(H2O)]−, formed under various source conditions, exhibit spectral features that are due to three different forms of the complex: the solvated anion–molecule complex, Ir−(H2O), as well as the intermediates, [H–Ir–OH]− and [H2–Ir–O]−, where one and two O–H bonds have been broken, respectively. The measured and calculated vertical detachment energy values are in good agreement and, thus, support identification of all three types of isomers. The calculated reaction pathway shows that the overall reaction Ir− + H2O → IrO− + H2 is exothermic. Two minimum energy crossing points were found, which shuttle intermediates and products between singlet and triplet potential surfaces. This study presents the first example of water activation and splitting by single Ir− anions. [ABSTRACT FROM AUTHOR]

Introduction. The first part of the paper reveals the concept and features of platinum group metals. According to the complex of considered parameters of each platinum group metals, including the market volume in physical and value terms, we distinguish three major (palladium, platinum, rhodium) and two minor (iridium, ruthenium) metals. For this research, the markets of five platinum group metals are identified as the object for factor analysis. Theoretical analysis. The platinum group metals market is systematized into two groups: supply factors and demand factors. It also analyzes primary and secondary sources of metals, and provides an overview of key application industries for each metal. Empirical analysis. Based on historical data, we compiled correlation matrices of fundamental factors interrelation between each other and with metal prices. Taking into account the identified correlation dependencies, regression models were developed, which, with a certain degree of accuracy, enable to forecast price dynamics. Results. Carrying out a factor analysis, in addition to stated dependencies and fundamental indicators quantitative assessments, we have summarized platinum group metals market trends.

Proton-exchange-membrane water electrolyzers (PEMWEs) produce high-purity H2, withstand load fluctuations, and operate with a pure-water feed but require platinum-group-metal catalysts for durability, such as IrO2 and Pt, due to the acidic environment. At the anode, the slow oxygen evolution reaction (OER) requires a high overpotential to achieve relevant current densities (>2 A·cm-2) even with a high loading of IrO2. Using a simple commercial 1,5-cyclooctadiene iridium chloride dimer precursor, we synthesized submonolayer-thick IrOx on the surfaces of conductive metal oxides to make every Ir atom available for catalysis and reach the ultimate lower limit for Ir loading. We show that the reaction on Sb/SnO2 and F/SnO2 conductive oxides is surface-limited and that a continuous Ir-O-Ir network provides improved stability and activity. We cover IrOx with a thin layer of acid-stable TiOx by atomic-layer deposition. The effects of TiOx on the catalyst’s performance were assessed by inductively coupled plasma mass spectrometry (ICP-MS) coupled in situ with an electrochemical flow cell and ex situ by X-ray photoelectron spectroscopy. Tuning the binding environment of IrOx by TiOx addition enhances the intrinsic activity of the active sites, simultaneously accelerating the dissolution of the catalyst and the metal-oxide support. We illustrate the interplay between the support, catalyst, and protection-layer dissolution with OER activity, and highlight the effects of annealing to densify the TiOx protection layer on stability/activity. These ultrathin supported Ir-based catalysts do not eliminate the long-standing issue of the catalyst and support instability during OER in acids, but do provide new insight into the catalyst-support interactions and may also be of utility for advanced spectroscopic investigations of the OER mechanism.

Atomically dispersed catalysts have been shown highly active for preferential oxidation of carbon monoxide in the presence of excess hydrogen (PROX). However, their stability has been less than ideal. We show here that the introduction of a structural component to minimize diffusion of the active metal center can greatly improve the stability without compromising the activity. Using an Ir dinuclear heterogeneous catalyst (DHC) as a study platform, we identify two types of oxygen species, interfacial and bridge, that work in concert to enable both activity and stability. The work sheds important light on the synergistic effect between the active metal center and the supporting substrate and may find broad applications for the use of atomically dispersed catalysts.

We report a class of isolable bis‐cyclometallated iridium precatalysts (ImIr) and their use in regioselective ortho−C−H borylation of aromatic, heteroaromatic, acrylic, and aliphatic systems. The catalysts consist of two imine ligands and an acetate coordinated to an iridium (III) center. The isolable character of ImIr warrants its compatibility with high‐throughput experimentation, a prerequisite for applications in late‐stage functionalization (LSF) of complex substrates. Initial mechanistic studies point towards an inner‐sphere mechanism involving bis‐cyclometallated species shedding light on the general mechanistic understanding of ortho‐selective C−H borylations. [ABSTRACT FROM AUTHOR]

A series of Ir(III)–naproxen (NPX) conjugates with the molecular formula [Ir(C^N)2bpy(4-CH2ONPX-4′-CH2ONPX)](PF6) (Ir-NPX-1–3) were designed and synthesized, including C^N = 2-phenylpyridine (ppy, Ir-NPX-1), 2-(2-thienyl)pyridine (thpy, Ir-NPX-2) and 2-(2,4-difluorophenyl)pyridine (dfppy, Ir-NPX-3). Cytotoxicity tests showed that Ir-NPX-1–3 exhibited excellent antitumor activity, especially in A549R cells. The cellular uptake experiment showed that the complexes were mainly localized in mitochondria, and induced apoptosis in A549R cells by damaging the structure and function of mitochondria. The main manifestations are a decrease in the mitochondrial membrane potential (MMP), an increase in reactive oxygen species (ROS) levels, and cell cycle arrest. Furthermore, Ir-NPX-1–3 could inhibit the migration and colony formation of cancer cells, demonstrating potential anti-metastatic ability. Finally, the anti-inflammatory and immunological applications of Ir-NPX-1–3 were verified. The downregulation of cyclooxygenase-2 (COX-2) and programmed death-ligand 1 (PD-L1) expression levels and the release of immunogenic cell death (ICD) related signaling molecules such as damage-associated molecular patterns (DAMPs) (cell surface calreticulin (CRT), high mobility group box 1 (HMGB1), and adenosine triphosphate (ATP)) indicate that these Ir(III) –NPX conjugates are novel ICD inducers with synergistic effects in multiple anti-tumor pathways. [ABSTRACT FROM AUTHOR]

Poor cellular permeability greatly hampers the utilization of anionic Ir(III) complexes, though efficiently emissive and remarkably stable, in cell-based diagnosis. To overcome this barrier, we present the development of an alkaline phosphatase (ALP)-responsive, anionic, and aggregation-induced emission (AIE)-active Ir(III) complex (Ir1) for specific recognition of osteosarcoma cells. Containing phosphate moieties, Ir1 exhibits a net −1 charge, enabling charge repulsion from the cell membrane and resulting in low cellular uptake and good biocompatibility in normal osteoblast cells. Upon ALP-mediated hydrolysis of phosphate groups, the resulting dephosphorylated product, Ir2, demonstrates a positive charge and increased lipophilicity, promoting cellular uptake and activating its AIE properties for specific recognition of osteosarcoma cells that express elevated levels of ALP. This study elucidates the role of ALP as an ideal trigger for enhancing the cellular permeability of phosphate ester-containing Ir(III) complexes, thus expanding the potential of anionic Ir(III) complexes for biomedical applications. [ABSTRACT FROM AUTHOR]

Catalysts that can promote the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) are in demand for efficient water splitting. Here, a general and practical UV‐induced synthesis of noble metal catalysts supported on reduced electrochemical graphene oxide (M‐rEGO, M = Ir, Pt or Pd) is proposed. The use of EGO with a low degree of oxidation and the generation of the highly reducing isopropanol radical from added isopropanol and acetone are crucial for this one‐step, one‐pot synthesis. Using Ir as a model material, the vacancies of rEGO allow the interaction of undercoordinated C with Ir, forming multiple active Ir species including single atoms (SAs), dual‐atom pairs (DAs) and nanoparticles. This Ir‐rEGO catalyst exhibits overpotentials of only 42.3 and 294 mV to reach 10 mA cm−2 in 0.5 м H2SO4 for HER and 1 м KOH for OER, respectively, at an extremely low Ir loading (2.1 wt%). The water‐splitting cells featuring Ir‐rEGO catalyst outperform those using commercial Pt/C (20 wt%) and RuO2 catalysts in both acidic and alkaline electrolytes. Density functional theory calculations confirm the stabilization of SAs and DAs at the vacancies of graphene lattice as well as the high activity of DAs in both HER and OER. [ABSTRACT FROM AUTHOR]

Highlights: Electrodeposited amorphous IrOx thin electrodes are first developed for proton exchange membrane electrolyzer cells. An ultralow loading of 0.075 mg cm−2 archives superior performance to catalyst-coated membrane (2 mg cm−2). > 96% of catalyst savings and > 42-fold higher catalyst utilization are demonstrated. Herein, ionomer-free amorphous iridium oxide (IrOx) thin electrodes are first developed as highly active anodes for proton exchange membrane electrolyzer cells (PEMECs) via low-cost, environmentally friendly, and easily scalable electrodeposition at room temperature. Combined with a Nafion 117 membrane, the IrOx-integrated electrode with an ultralow loading of 0.075 mg cm−2 delivers a high cell efficiency of about 90%, achieving more than 96% catalyst savings and 42-fold higher catalyst utilization compared to commercial catalyst-coated membrane (2 mg cm−2). Additionally, the IrOx electrode demonstrates superior performance, higher catalyst utilization and significantly simplified fabrication with easy scalability compared with the most previously reported anodes. Notably, the remarkable performance could be mainly due to the amorphous phase property, sufficient Ir3+ content, and rich surface hydroxide groups in catalysts. Overall, due to the high activity, high cell efficiency, an economical, greatly simplified and easily scalable fabrication process, and ultrahigh material utilization, the IrOx electrode shows great potential to be applied in industry and accelerates the commercialization of PEMECs and renewable energy evolution. [ABSTRACT FROM AUTHOR]

The noncovalent interactions of ammonium ion with multidentate oxygen-based host has never been reported as a reacting center in catalytic reactions. In this work, we report a reactivity enhancement process enabled by non-covalent interaction of ammonium ion, achieving the C–H functionalization of polyethylene glycols with acrylates by utilizing photoinduced co-catalysis of iridium and quinuclidine. A broad scope of alkenes can be tolerated without observing significant degradation. Moreover, this cyano-free condition respectively allows the incorporation of bioactive molecules and the PEGylation of dithiothreitol-treated bovine serum albumin, showing great potentials in drug delivery and protein modification. DFT calculations disclose that the formed α-carbon radical adjacent to oxygen-atom is reduced directly by iridium before acrylate addition. And preliminary mechanistic experiments reveal that the noncovalent interaction of PEG chain with the formed quinuclidinium species plays a unique role as a catalytic site by facilitating the proton transfer and ultimately enabling the transformation efficiently. The noncovalent interaction of ammonium ion with multidentate oxygen-based host serving as a key reacting center in catalytic reactions is rare. In this work, the authors report a noncovalent interaction of ammonium ion enabled reactivity enhancement process, achieving the C–H functionalization of polyethylene glycols with acrylates. [ABSTRACT FROM AUTHOR]

A C(sp3)–C(sp3) cross coupling approach based on an iridium-photocatalytic radical process has been developed enabling the synthesis of various α-alkylated aldehydes from easily available/synthesized alkyl bromides and trialkyl amines under mild photocatalytic conditions. The synthesized aldehydes are also explored as a functional handle for various useful products such as carboxylic acid, alcohol and N-heterocycle synthesis. [ABSTRACT FROM AUTHOR]

Herein, we present luminescent mononuclear iridium complexes [1]3+–[4]3+ using NEt3-appended C^N chelating benzimidazole (L1–L4) and semi-flexible phenanthroline-pyrazine-based (phpy) ligands exhibiting photocatalytic reduction of 4-nitrophenol (4-NP) in the presence of NEt3 in an aqueous medium. The formation of [1]3+–[4]3+ was confirmed by HRMS, 1H–1H COSY, and 13C and 19F NMR spectroscopy. The complex [4]3+ is water soluble, whereas the others ([1]3+–[3]3+) are partially soluble. The complexes are luminescent in both CH3CN and H2O media. The DFT study reveals that the HOMO of [1]3+ resides on the C^N chelating benzimidazole and iridium center. However, it moves to the pyrazine-pyridine of the phpy unit in the case of [2]3+–[4]3+. The LUMOs are localized on the phenanthroline unit of phpy for all the complexes. This suggests an important role of the fluorine atom on electron density distribution. Spin density analysis demonstrates that the emission bands of the complexes arise from 3MLLCT states. The complex [4]3+ displays promising photocatalytic activity towards 4-NP photoreduction, whereas complexes [1]3+–[3]3+ exhibit lower reactivity. The mechanistic study suggests that the reaction proceeds through an oxidative quenching pathway, where 4-NP is reduced by accepting an electron from excited [Ir(III)] and gets oxidized to Ir(IV), which comes back to its original Ir(III) state by accepting an electron from the sacrificial electron donor NEt3. [ABSTRACT FROM AUTHOR]

A series of nine luminescent iridium(III) complexes with pH-responsive imidazole and benzimidazole ligands have been prepared and characterized. The first series of complexes were of the form [Ir(ppy)2(N^N)]+ or [Ir(ppy)2(C^N)]+ (where ppy is 2-phenylpyridine and N^N is 2-(2-pyridyl)imidazole or 2-(2-pyridyl)benzimidazole and C^N represents a pyridyl-triazolylidene-based N-heterocyclic carbene ligand). For these complexes, the benzimidazole group was either unsubstituted or substituted with electron-withdrawing (Cl) or electron-donating (Me) groups. The second series of complexes were of the form [Ir(phbim)2(N^N)]+ or [Ir(phbim)2(C^N)]+ (where phbim is 2-phenylbenzimidazole and N^N is either 2,2′-bipyridine or 1,10-phenanthroline and C^N is either a pyridyl-imidazolylidene or pyridyl-triazolylidene N-heterocyclic carbene ligand). UV-visible and photoluminescence pH titration studies showed that changing the protonation state of these complexes results in significant changes in the photoluminescence emission properties. The pKa values of prepared complexes were estimated from the spectroscopic pH titration data and these values show that the nature of the pH-sensitive ligands (either main or ancillary ligands) resulted in a significant capacity to modulate the pKa values for these compounds with values ranging from 5.19–11.22. Theoretical investigations into the nature of the electronic transitions for the different protonation states of compounds were performed and the results were consistent with the experimental results. [ABSTRACT FROM AUTHOR]

Hydroxide exchange membrane fuel cells (HEMFCs) have the advantages of using cost-effective materials, but hindered by the sluggish anodic hydrogen oxidation reaction (HOR) kinetics. Here, we report an atomically dispersed Ir on Mo2C nanoparticles supported on carbon (IrSA-Mo2C/C) as highly active and stable HOR catalysts. The specific exchange current density of IrSA-Mo2C/C is 4.1 mA cm−2ECSA, which is 10 times that of Ir/C. Negligible decay is observed after 30,000-cycle accelerated stability test. Theoretical calculations suggest the high HOR activity is attributed to the unique Mo2C substrate, which makes the Ir sites with optimized H binding and also provides enhanced OH binding sites. By using a low loading (0.05 mgIr cm−2) of IrSA-Mo2C/C as anode, the fabricated HEMFC can deliver a high peak power density of 1.64 W cm−2. This work illustrates that atomically dispersed precious metal on carbides may be a promising strategy for high performance HEMFCs. High-performance hydroxide exchange membrane fuel cells rely on the anode loading of platinum-group metals. Here, the authors report a highly active hydrogen oxidation electrocatalyst which contains atomically dispersed Ir on Mo2C nanoparticles supported on a carbon substrate. [ABSTRACT FROM AUTHOR]

Nanostructured niobium–titanium carbonitrides, (Nb,Ti)-C1–xNx, with the cubic-rock salt structure are prepared without the use of reactive gases via thermal treatment (700–1200 °C) under nitrogen of mixtures of guanidine carbonate and ammonium niobate (V) oxalate hydrate, with addition of ammonium titanyl oxalate monohydrate as a titanium source. The bulk structure and chemical composition of the materials are characterized using powder X-ray diffraction (XRD) and powder neutron diffraction, elemental homogeneity is studied using energy dispersive spectroscopy (EDS) mapping using transmission electron microscopy (TEM), and surface chemical analysis is examined using X-ray photoelectron spectroscopy (XPS). Nanoscale crystallites of between 10 and 50 nm are observed by TEM, where EDS reveals the homogeneity of metal distribution for the mixed-metal materials. Titanium carbonitrides are found to be air sensitive, reacting with air under ambient conditions, while titanium–niobium carbonitrides are found to degrade in aqueous sulfuric acid. The niobium carbonitrides, however, show some stability toward acidic solutions. Materials are produced with composition NbC1–xNx with x between 0.35 and 0.45, and more carbon-rich materials (x ≈ 0.35) are found as the synthesis temperature is increased, as proven by Rietveld refinement of crystal structure against powder neutron diffraction data. Despite phase purity seen by diffraction and negligible bulk carbon content, XPS shows a complex surface chemistry for the NbC1–xNx materials, with evidence for Nb2O5-like oxide species in a carbon-rich environment. The NbC1–xNx prepared at 900 °C has a surface area around 50 m2 g–1, making it suitable as a catalyst support. Loading with iridium provides a material active for the oxygen evolution reaction in 0.1 M sulfuric acid, with minimal leaching of either Nb or Ir after 1000 cycles. [ABSTRACT FROM AUTHOR]

Transition metal complexes containing the qtpy ligand (2':4,4":4',4"'-quaterpyridyl) are known to be DNA intercalators or minor groove binders. In this study, new tricationic iridium(III) complexes of qtpy are reported. Both [Ir(bpy)2(qtpy)]3+ 1 and [Ir(phen)2(qtpy)]3+ 2 display good water solubility as chloride salts. The complexes possess high-energy excited states, which are quenched in the presence of duplex DNA and even by the mononucleotides guanosine monophosphate and adenosine monophosphate. Further studies reveal that although the complexes bind to quadruplex DNA, they display a preference for duplex structures, which are bound with an order of magnitude higher affinities than their isostructural dicationic RuII-analogues. Detailed molecular dynamics simulations confirm that the complexes are groove binders through the insertion of, predominantly, the qtpy ligand into the minor groove. Photoirradiation of 1 in the presence of plasmid DNA confirms that this class of complexes can function as synthetic photonucleases by cleaving DNA. [ABSTRACT FROM AUTHOR]

In this investigation, the sol-gel spin coating technique was utilized to fabricate ZnO and ZnO films doped with Iridium (Ir) onto p-Si substrates. The objective was to analyze their optical and morphological characteristics and assess their potential for heterojunction applications. Morphological inspection and optical evaluation were carried out by Atomic Force Microscopy (AFM) and Ultraviolet-visible (UV-VIS) studies, respectively. With the incorporation of Ir, the optical band gap of ZnO films reduced from 3.21 eV to 3.08 eV. Analysis of AFM images revealed that Ir substitution led to a reduction in the roughness of the surface of the fabricated films. The optoelectrical features of the heterojunction structures were examined under varying illumination levels and in dark conditions. Upon evaluating the optoelectrical characteristics of the produced diodes, it was observed that the ideality factor (n) and the barrier height (OB) declined, while series resistance (fls) increased with the introduction of Ir. These findings emphasize that the inclusion of Ir into the ZnO structure has a discernible impact on optical parameters. [ABSTRACT FROM AUTHOR]

The development of acid‐stable oxygen evolution reaction electrocatalysts is essential for high‐performance acidic water electrolysis. Herein, we report the results of one‐dimensional (1D) nanorods (NRs) IrCeMnO@Ir containing ~20 wt. % Iridium (Ir) as an efficient anode electrocatalyst, synthesized via a one‐step cation exchange strategy. Owing to the presence of 1D channels of the nanorod architecture and the unique electronic structure, the IrCeMnO@Ir exhibited 69 folds more mass activity than that of commercial IrO2 as well as over 400 h stability with only a 20 mV increase in overpotential. DFT calculations and control experiments demonstrated that CeO2 serves as an electron buffer to accelerate the kinetics of the rate‐determined step for the significantly enhanced activity and suppress the over‐oxidation of Ir species as well as their dissolution for impressively promoted stability under practical conditions. Our work opens up a feasible strategy to boost OER activity and stability simultaneously. [ABSTRACT FROM AUTHOR]

Herein, we report the development of a macromolecular multifunctional imaging tool for biological investigations, which is comprised of an N‐(2‐hydroxypropyl)methacrylamide backbone, iridium‐based luminescent probe, glutamate carboxypeptidase II (GCPII) targeting ligand, and biotin affinity tag. The iridium luminophore is a tris‐cyclometalated complex based on [Ir(ppy)3] with one of its 2‐phenylpyridine ligands functionalized to allow conjugation. Synthesized macromolecular probes differed in the structure of the polymer and content of the iridium complex. The applicability of the developed imaging tools has been tested in flow cytometry (FACS) based assay, laser confocal microscopy, and fluorescence lifetime imaging microscopy (FLIM). The FACS analysis has shown that the targeted iBodies containing the iridium luminophore exhibit selective labelling of GCPII expressing cells. This observation was also confirmed in the imaging experiments with laser confocal microscopy. The FLIM experiment has shown that the iBodies with the iridium label exhibit a lifetime greater than 100 ns, which distinguishes them from typically used systems labelled with organic fluorophores exhibiting short fluorescence lifetimes. The results of this investigation indicate that the system exhibits interesting properties, which supports the development of additional biological tools utilizing the key components (iridium complexes, iBody concept), primarily focusing on the longer lifetime of the iridium emitter. [ABSTRACT FROM AUTHOR]

The mechanisms of the Cp*IrIII(bpyOO)‐catalyzed (bpyOO=bidentate (NN) doubly deprotonated 2,2′‐bipyridine‐6,6′‐diol) acceptorless methanol dehydrogenation and acetophenone transfer hydrogenation by methanol under basic conditions have been explored by the combination of 1H NMR, kinetics, and DFT computational studies. During dehydrogenation of methanol and of its dehydrogenated derivatives, the presence of two iridium hydride species (anionic [Cp*Ir(bpyOO)H]−, C* and neutral [Cp*Ir(bpyOOH)H], D*), which interconvert depending on pH, was detected. The DFT studies on a Cp model system highlighted three interrelated catalytic cycles of methanol, formaldehyde and formic acid dehydrogenation, all leading to the same hydride intermediates C and D. The dehydrogenation of methanol prefers a direct β‐hydride transfer pathway from the methoxide ion to Ir, rather than the classical β‐hydride elimination pathway from a coordinated methoxide ligand, but an alternative bifunctional H+/H− transfer with involvement of a ligand O atom may become competitive at lower pH. The transfer hydrogenation of acetophenone using methanol as hydrogen source features species C* as resting state, with the acetophenone reduction being rate‐determining and following the reverse pathway of methanol oxidation, with a first‐order acetophenone decay and a kinetic isotope effect of 2.36±0.09. [ABSTRACT FROM AUTHOR]

Isonitriles are useful reagents that participate in many cycloaddition or multicomponent reactions of interest in organic synthesis, which are often catalyzed by transition metal complexes. Being good electron donors, RN=C bonds become activated and prone to the nuclephilic attack upon coordination to electrophilic (Lewis acidic) metal centers. Herein we explore the complexation of tBuNC to a series of iridium hydrido chlorides supported by benzene-based pincer ligands, ()IrH(Cl) ( = κ3‑C6H3–2,6-(ZPtBu2)2, where R = H (I–III), EtCO2–(IV), and Z = CH2 (I), CH2, O (II), O (III, IV)), that occurs instantaneously and quantitatively in solution yielding one of possible isomers Ia–IVa. Single crystal X-ray diffraction studies for Ia–IIIa confirmed the apical coordination of isonitrile ligand trans to hydride ligand suggested by NMR studies. Perusal of the structural data suggests stronger binding of tBuNC to PCP-supported iridium center in complex Ia in comparison to PCOP/POCOP species IIa–IIIa. Structural data also reveal a distortion in the P–Ir–P arrangement caused by tBuNC docking in apical position that is the most noticeable for asymmetric PCOP version IIa. The computational analysis of vibrational frequencies unveils an essential coupling νIr-H and νN=С modes that produce two strong bands of similar intensity in the νN=C region for Ia. Weaker isonitrile binding in IIa–IVa with shorter N=С and longer N– /Ir–CCN bonds and a plethora of intramolecular interactions result in a different degree of vibrational mixing for Ir‒H and N=C stretches as well as lead to an intense bands due to a Fermi resonance of low frequency modes involving vibrations of N–C–tBu fragment. Thus, the raw experimental IR data should be taken with care as an indicator of RN=С activation, paying attention to the vibrational coupling. An estimation of band position for the "true" (uncoupled) νNC vibration gives a small high frequency shift for Ia (+16 cm–1) but low frequency shifts for other complexes becoming less negative in the order IIa–IIa–IVa (PCOP–POCOP– EtCO2-POCOP). Overall the results obtained show the influence of the pincer ligand on the complex picture of isonitrile complexes structure and spectra, and suggest that strong binding does not always mean a strong activation. [ABSTRACT FROM AUTHOR]

The reaction between ZrC and iridium powders was studied in the temperature range of 1000–1600°C. The reaction was stated to start at a temperature as low as 1000°C. The only high‐melting intermetallic phase, ZrIr3, was obtained as a substitutional solid solution ZrIr3±δ. A new analytical approach to relating the composition to the lattice parameter of cubic binary substitutional ZrIr3±δ solid solutions was proposed. This approach is based on comparing the distribution by elemental composition and by lattice parameter in a range of ZrIr3±δ solid solutions. This made it possible to determine the lattice parameter of a stoichiometric ZrIr3 phase, a0 = 3.971(5) Å. [ABSTRACT FROM AUTHOR]

In recent years, there has been growing exploration of organometallic transition metal complexes as promising options for developing anticancer agents that offer the potential of reduced toxicity compared with the commonly utilized cisplatin analogs. In this respect, iridium complexes containing 2-phenylimidazo- [4,5-f][1,10]-phenanthroline derivatives with different substituents were investigated in different cell lines as potential anticancer agents. All the compounds exhibited potent cytotoxic activity against Caco-2, HeLa, A549, and MDA-MB-231 cell lines. EC50 values of compound 1 were found to be 6.44 μM for Caco-2, 24.78 μM for HeLa, 9.14 μM for A549, and 4.45 μM for the MDA-MB-231 cell line. Similarly, EC50 of 3 was found at 15.07, 14.15, 10.33, and 4.48 μM respectively. The EC50 value of 2 was found to be 12.71 μM for Caco-2, 24.31 μM for HeLa, and 7.44 μM for MDA-MB-231 cells. EC50 values of compound 4 were found to be 28.20 μM for Caco-2, 12.79 μM for HeLa, 8.33 μM for A549, and 3.76 μM for the MDA-MB-231 cell line. The results of gene expression and flow-cytometry analysis showed that the compounds caused the induction of apoptosis in all cancer cell lines by changing caspase 3, Bcl-2, and Bax proteins. The obtained results demonstrate that compounds could be introduced as potent agents to prevent the progression of certain types of cancer. However, preclinical and clinical trials will be needed to evaluate these complexes to obtain safe, effective, and optimal therapeutic drugs for cancer patients. [ABSTRACT FROM AUTHOR]

This study used micro-analyses, (FTIR, UV-Vis) spectra, magnetic, thermogravimetric, X-ray powder diffraction (XRD) patterns, and transmittance electron microscopy (TEM) techniques to characterize three synthesized theophylline (TPH) complexes with ruthenium(III), platinum(IV), and iridium(III) metal ions. The metal ions indicated above were found to align with the TPH drug chelate as a mono-dentate ligand via the deprotonated NH group at the nitrogen atom position N7, as verified by FTIR measurements. Additionally, the complexes conductivity and magnetic susceptibility were examined. The octahedral geometry for the synthesized complexes was proposed by the current data. Except for the iridium(III) complex, which has a non-electrolytic nature due to the presence of a chlorine atom inside the chelation sphere, the molar conductivity of the complexes in DMSO solution was electrolyte in nature. Theophylline complexes with a (metal: ligand) stoichiometry of 1:2 were produced. The TPH complexes have also been tested in vitro against G(+) bacteria (Bacillus subtilis and Staphylococcus Aureus) and G(-) bacteria (Pseudomonas aeruginosa and Escherichia coli) to evaluate their antibacterial efficacy. Human breast and liver cancer cell lines were used as a test for the TPH complexes in vitro anti-cancer properties. [ABSTRACT FROM AUTHOR]

Ruthenium(III), gold(III), and iridium(III) trimethoprim drug (TMP) complexes were synthesized and analyses via microanalytical approach (C, H, N analysis), magnetic, molar conductance, and FTIR, 1H NMR, XRD, and UV-Vis spectroscopy. Through two nitrogen atoms of --NH2 amino groups, the TMP drug coordinated as a bidentate ligand towards the corresponding three metal ions. The geometrical structure of the compounds ruthenium(III), gold(III), and iridium(III) is octahedral and consists of two TMP molecules, two coordinated chlorine atoms, and one uncoordinated chlorine atom. The antibacterial properties of TMP complexes have been investigated through the use of many bacterial species, including Pseudomonas aeruginosa, Bacillus subtilis, Staphylococcus aureus, and Escherichia coli. Additionally, the generated complexes' anticancer properties against HepG-2 (human hepatocellular carcinoma) and MCF-7 (human breast cancer cell line) have been assessed. In contrast to those of clinically used antibiotics, the inhibition zone of ruthenium and iridium(III) complexes was in the low efficiency range, and the antibacterial activity of gold(III) complexes was moderate. This article discusses the possibilities and prospects for this family of metallodrugs as antibacterial or anticancer medicines. [ABSTRACT FROM AUTHOR]

We present a luminescent Ir(III) complex featuring a bidentate halogen bond donor site capable of strong anion binding. The tailor‐made Ir(III)(L)2 moiety offers a significantly higher emission quantum yield (8.4 %) compared to previous Ir(III)‐based chemo‐sensors (2.5 %). The successful binding of chloride, bromide and acetate is demonstrated using emission titrations. These experiments reveal association constants of up to 1.6×105 M−1. Furthermore, a new approach to evaluate the association constant by utilizing the shift of the emission was used for the first time. The experimentally observed characteristics are supported by quantum chemical simulations. [ABSTRACT FROM AUTHOR]

Peroxidase mimics made of inorganic nanomaterials as alternatives to natural peroxidases have been extensively developed over the past few decades, owing to their superior properties relative to their natural counterparts. Nevertheless, it has been still a challenge to substantially enhance the catalytic efficiency of peroxidase mimics. In this work, we report a type of highly efficient peroxidase mimics that are made of iridium nanoparticles (Ir NPs) with rough surfaces. The Ir NPs possess an ultrahigh catalytic efficiency with a catalytic constant (Kcat) at the regime of 1010 s−1, orders of magnitude higher than the Kcat of horseradish peroxidase as a natural peroxidase. As a proof‐of‐concept demonstration, the Ir NPs were applied to colorimetric lateral flow assay (CLFA). Using carcinoembryonic antigen as a model disease biomarker, the Ir NPs‐based CLFA achieved a low limit of detection (LoD) of 39 pg/mL, which was ~28 times lower than the LoD of conventional gold nanoparticles‐based CLFA using the same antibodies. [ABSTRACT FROM AUTHOR]

Single-atom catalysts (SACs) with high catalytic activity as well as great stability are demonstrating great promotion in electrocatalytic energy conversion, which is also a big challenge to achieve. Herein, we proposed a facile synthetic strategy to construct nickel-iron bimetallic hydroxide nanoribbon stabilized single-atom iridium catalysts (Ir-NiFe-OH), where the nickel-iron hydroxide nanoribbon not only can serve as good electronic conductor, but also can well stabilize and fully expose single-atom sites. Adopted as catalyst for urea oxidation reaction (UOR), it exhibited excellent UOR performance that it only needed a low operated potential of 1.38 V to achieve the current density of 100 mA·cm−2. In-situ Fourier transform infrared spectroscopy, X-ray absorption spectrum, and density functional theory calculations proved that Ir species are active centers and the existence of both Ni and Fe in the local structure of Ir atom can optimize the d-band center of Ir species, promoting the adsorption of intermediates and desorption of products for UOR. The hydrogen evolution reaction (HER)/UOR electrocatalytic cell demanded voltages of 1.46 and 1.50 V to achieve 50 and 100 mA·cm−2, respectively, which demonstrated a higher activity and better stability than those of conventional catalysts. This work opens a new avenue to develop catalysts for UORs with boosted activity and stability. [ABSTRACT FROM AUTHOR]

The discovery of new compounds with pharmacological properties is usually a lengthy, laborious and expensive process. Thus, there is increasing interest in developing workflows that allow for the rapid synthesis and evaluation of libraries of compounds with the aim of identifying leads for further drug development. Herein, we apply combinatorial synthesis to build a library of 90 iridium(III) complexes (81 of which are new) over two synthesise‐and‐test cycles, with the aim of identifying potential agents for photodynamic therapy. We demonstrate the power of this approach by identifying highly active complexes that are well‐tolerated in the dark but display very low nM phototoxicity against cancer cells. To build a detailed structure–activity relationship for this class of compounds we have used density functional theory (DFT) calculations to determine some key electronic parameters and study correlations with the experimental data. Finally, we present an optimised semi‐automated synthesise‐and‐test protocol to obtain multiplex data within 72 hours. [ABSTRACT FROM AUTHOR]

The synthesis, characterization and application of a new complex, [Ir(κ2‐P,N‐6‐DCyPon*)(COD)] (1), where 6‐DCyPon* is the anionic species, 6‐dicyclohexylphosphino‐2‐oxo‐pyridinide, is reported herein. Complex 1 was found to be an active catalyst in the hydrogenation of CO2 at room temperature. The ligand, 6‐DCyPon*, is derived via deprotonation of a novel pro‐ligand, 6‐DCyPon (6‐dicyclohexylphosphino‐2‐pyridone) during the synthesis of 1. The ligand is shown to participate within the reversible hydrogenation of 1, via a cooperative process, in which the species, [IrH3(κ2‐P,N‐6‐DCyPon)(COD)] (2), was spectroscopically characterized, where 1 reacts with two equivalents of H2. [ABSTRACT FROM AUTHOR]

Based on the explosive nature and harmful effects of nitro-based explosive materials on living beings and the environment, it is extremely important to develop luminescence-based probe molecules for their detection with excellent selectivity and sensitivity. Two AIPE (aggregation-induced phosphorescence emission)-active iridium(III) complexes (M1 and M2) were developed for the sensitive detection of TNT in both contact and non-contact modes. The aggregate solutions of both complexes (M1 and M2 in THF/H2O, 1/9 by volume) detected TNT at the pico-molar (pM) level. These complexes showed greatly enhanced emission intensity while embedded in a PMMA(polymethyl methacrylate) matrix film. The amplified quantum efficiency, improved phosphorescence lifetime, and enhanced porous network of M2-PMMA composite helps to improve the sesitivity of TNT vapor detection. Interestingly, the sensitivity of the detection of TNT by the M2 complex was significantly improved (5-fold) in a PMMA-incorporated complex (CP) with an observed limit of detection (LOD) of 12.8 ppb. From the BET analysis of CP, it was observed that the mesoporous network of CP has an average pore diameter of 8.52 nm and a surface area of 2.03 m2 g−1. The porous network of CP assists in trapping TNT vapor in a polymeric network containing an electron-rich probe (iridium(III) complex, M2), which helps to effectively trap TNT, thus enhancing electronic communication. As a result, significant emission quenching was observed. [ABSTRACT FROM AUTHOR]

The masked transition‐metal frustrated Lewis pairs [Cp*M(κ3N,N',N"‐L)][SbF6] (Cp*=η5‐C5Me5; M=Ir, 1, Rh, 2; HL=pyridinyl‐amidine ligand) reversibly activate H2 under mild conditions rendering the hydrido derivatives [Cp*MH(κ2N,N'‐HL)][SbF6] observed as a mixture of the E and Z isomers at the amidine C=N bond (M=Ir, 3Z, 3E; M=Rh, 4Z, 4E). DFT calculations indicate that the formation of the E isomers follows a Grotthuss type mechanism in the presence of water. A mixture of Rh(I) isomers of formula [(Cp*H)Rh(κ2N,N'‐HL)][SbF6] (5 a–d) is obtained by reductive elimination of Cp*H from 4. The formation of 5 a–d was elucidated by means of DFT calculations. Finally, when 2 reacts with D2, the Cp* and Cp*H ligands of the resulting rhodium complexes 4 and 5, respectively, are deuterated as a result of a reversible hydrogen abstraction from the Cp* ligand and D2 activation at rhodium. [ABSTRACT FROM AUTHOR]

Due to multidrug resistance and the high risk of recurrence, effective and less toxic alternative pancreatic cancer treatments are urgently needed. Pancreatic cancer cells are highly resistant to apoptosis but sensitive to ferroptosis. In this study, an innovative nanoplatform (AsIr@PDA) was developed by electrostatic adsorption of a cationic iridium complex (IrFN) onto two‐dimensional (2D) arsenene nanosheets. This nanoplatform exhibits superior ferroptosis‐inducing effects with high drug loading capacity and, importantly, excellent anti‐cancer immune activation function, leading to efficient elimination of pancreatic tumors with no observable side effects. Interestingly, AsIr@PDA significantly prevents the recurrence of pancreatic cancer in vivo when compared with a cisplatin‐loaded nanoplatform. This designed nanoplatform demonstrated superior therapeutic efficacy by synergistic ferroptosis‐induced chemotherapy with immunotherapy via an all‐in‐one strategy, providing new insights for future pancreatic cancer therapy. [ABSTRACT FROM AUTHOR]

The application of Mg[Ph4Pn] and Li·K[Ph4Pn] in transmetalation reactions to a range of Rh(I) precursors led to the formation of "half-baguette" anti-[Rh I(L) n ]2[μ:η5:η5Ph4Pn] (L = 1,5-cyclooctadiene, norbornadiene, ethylene; n = 1, 2) and syn-[Rh I(CO)2]2[μ:η5:η5Ph4Pn] complexes as well as the related iridium complex anti-[Ir I(COD)]2[μ:η5:η5Ph4Pn]. With CO exclusive syn metalation was obtained even when using mono-nuclear Rh(I) precursors, indicating an electronic preference for syn metalation. DFT analysis showed this to be the result of π overlap between the adjacent M(CO)2 units which overcompensates for dz2 repulsion of the metals, an effect which can be overridden by steric clash of the auxiliary ligands to yield anti-configuration as seen in the larger olefin complexes. syn-[Rh I(CO)2]2[μ:η5:η5Ph4Pn] is a rare example of a twinned organometallic where the two metals are held flexibly in close proximity, but the two d8 Rh(I) centres did not show signs of M–M bonding interactions or exhibit Lewis basic behaviour as in some related mono-nuclear Cp complexes due to the acceptor properties of the ligands. The ligand substitution chemistry of syn-[Rh I(CO)2]2[μ:η5:η5Ph4Pn] was investigated with a series of electronically and sterically diverse donor ligands (P(OPh)3, P(OMe)3, PPh3, PMe3, dppe) yielding new mono- and bis-substituted complexes, with E-syn-[Rh I(CO)(P{OR})3]2[μ:η5:η5Ph4Pn] (R = Me, Ph) characterised by XRD. [ABSTRACT FROM AUTHOR]

A group of new iridium(III) complexes were rationally designed and synthesized with 2‐phenylbenzo[d]oxazole (bo), 2‐phenylbenzo[d]thiazole (bt), 2‐(thiophen‐2‐yl)benzo[d]thiazole (thbt), and 2‐(selenophen‐2‐yl)benzo[d]thiazole (sebt) as C^N ligands and bis(diphenylthiophosphoryl)amide (S‐tpip) as ancillary ligand. They are phosphorescent in a wide region of green to red with short lifetimes around 0.31–0.98 μs and quantum yields up to 64.7%. The detailed photophysical properties were investigated by experiment and further supported by density functional theory (DFT) calculation. These research results show that the spectroscopic properties are tuned by the replacement between oxygen, sulfur, and selenium or the change in aromatic ring. It has been demonstrated that the lowest energy‐level absorption and emission are dominated apparently by C^N ligands, and are ascribed to metal‐to‐ligand charge transfer (MLCT) and intra‐ligand charge transfer (ILCT) characters. [ABSTRACT FROM AUTHOR]