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A simple and mild stimulus-responsive fluorescent supramolecular polymer network was constructed from a pillararene-based multi-functional monomer through multiple noncovalent interactions and used as a rewritable paper. [ABSTRACT FROM AUTHOR]

A new CdII-based luminescent metal–organic framework (LMOF) with the formula {[Cd(BIBT)(NDC)]·solvents}n (JXUST-32, BIBT = 4,7-bi(1H-imidazol-1-yl)benzo-[2,1,3]thiadiazole and H2NDC = 2,6-naphthalenedicarboxylic acid) was successfully synthesized by a solvothermal method. JXUST-32 shows a two-dimensional (4,4)-connected network and exhibits significant fluorescence red shift and slight enhancement for H2PO4− and CO32− sensing with detection limits of 0.11 and 0.12 μM, respectively. In addition, JXUST-32 has good thermal stability, chemical stability and recyclability. Significantly, JXUST-32 represents a fluorescence red-shift dual response MOF sensor for H2PO4− and CO32− detection and the analytes can be identified by the naked eye, aerosol jet printing filter paper, light-emitting diode beads and luminescent films. [ABSTRACT FROM AUTHOR]

In the practical application of microwave absorbing materials, traditional powder materials need to be mixed with the matrix to fabricate composite coatings. However, the complex preparation process of composite coatings and the uneven dispersion of powders in the matrix limit their application. To solve these problems, two-dimensional (2D) F-WS2/CP composite films were prepared by using carbon paper (CP) as a dispersion matrix and loading flower-like WS2 on its surface through a simple hydrothermal method. The morphology and microwave absorption (MA) performance of the composite films are easily regulated by adjusting the amount of reaction precursors. The combination of WS2 and CP facilitates impedance matching and improves the electromagnetic wave attenuation performance based on the synergistic effect of different loss mechanisms including multiple reflections and scattering, interfacial polarization, dipolar polarization, and conduction loss. At a low filler content (5 wt%), the maximum reflection loss (RL) of the composite film is up to -50 dB (99.999% energy absorption) at 12.5 GHz with 2.8 mm thickness. Moreover, at a relatively thin 1.8 mm thickness, its maximum RL remains -35 dB (>99.9% energy absorption). The as-prepared composite film shows excellent MA properties at a thinner thickness and lower filling content, providing inspiration for the preparation of light weight and efficient 2D thin-film microwave absorbers in the future. [ABSTRACT FROM AUTHOR]

The effective integration of nanomaterials with underlying current collectors is a key factor affecting the performance of nonenzymatic glucose sensors, where an inappropriate integration structure often leads to poor electron transport and instability. In this work, a seamless integrated electrode was constructed by the in situ immobilizing of a nickel-based metal-organic framework (Ni-MOF) on a three-dimensional (3D) conductive nickel foam (NF) for highly sensitive and durable glucose sensing. Facilitated by a rapid microwave-assisted reaction, a robust interfacial interaction between the Ni-MOF and the substrate was established through in situ conversion from nickel oxide (NiO). The fabricated Ni-MOF/NF electrode exhibits an excellent limit of detection (LOD) of 2.65 μM and an impressive sensitivity (14.31 mA cm-2 mM-1) within the linear range (4-576 μM), which is significantly boosted compared with that of an electrode prepared by a typical drop-casting method (3.56 mA cm-2 mM-1 in 4-1836 μM). Characterization and electrochemical tests reveal that this integrated structure on the one hand contributes to fast electron transport and thus has enhanced sensitivity and on the other hand leads to exceptional durability with its structural integrity maintained under bending, shaking, and ultrasonication. Moreover, this seamless integration method was also employed to immobilize the Ni-MOF converted from the pre-chemically deposited NiO layer on another type of substrate, 3D carbon paper (CP), demonstrating the versatility of this facile strategy in creating diverse electrochemical electrodes for applications beyond glucose sensing. [ABSTRACT FROM AUTHOR]

The combination of electron-deficient viologen ligands with electron-rich POMs is a typical acceptor–donor system that has recently received much attention. Under solvothermal and hydrothermal conditions, by introducing three symmetric viologen ligands into POM-based hybrid materials, we successfully constructed four POMs–viologen inorganic–organic hybrid compounds, namely (1,3-bcbpy)2·(δ-Mo8O26) (1) (1,3-bcbpy·2Cl = 1,1′-bis(3-carboxybenzyl)-4,4′-bipyridine dichloride), {CoII(1,4-bcbpy)2(H2O)2[H2(β-Mo8O26)]}·2H2O·2CH2O (2), (1,4-bcbpy)2·(δ-Mo8O26)·2H2O (3) (1,4-bcbpy·2Cl = 1,1′-bis(4-carboxybenzyl)-4,4′-bipyridine dichloride, CH2O = formaldehyde), and {CuII(1,1-pmbby)2(H2O)[H2(β-Mo8O26)2]}·5H2O·C2H7N (4) (1,1-pmbby·2Cl = 1,1′-[1,4-phenylbis(methylene)]bis-(4,4′-bipyridine)dichloride, C2H7N = dimethylamine). These four compounds exhibit different fascinating structures, especially compound 4 is a typical metal–organic framework. Compounds 1–4 exhibit good discoloration behaviors under various external stimuli. For example, compounds 1–4 showed a positive response to the irradiation from a 300 W Xe lamp. When a positive voltage was applied to the ECD based on compounds 1–4, 1/2/3/4-ECD underwent a significant color conversion. What's more, compound 4 also showed obvious discoloration results after heating. In a word, 1–4 are multifunctional discoloration materials under different external stimuli. In addition, the coated filter paper prepared based on compound 3 can be used as a new printing material medium and can be successfully applied in erasable inkless printing and dual anti-counterfeiting. [ABSTRACT FROM AUTHOR]

The development of flexible current collectors as an indispensable component in energy storage devices has been in strong demand for the ever-growing market of flexible and wearable electronics. Herein, flexible and conductive paper-based current collectors are fabricated by directly depositing a metallic Ni layer composed of spiny Ni nanospheres of 400 nm diameter on the surface of filter paper via electroless deposition. The metallic paper shows excellent electric and mechanical properties: the sheet resistance is 2.7 Ω cm−2 (R0 = 0.8 Ω cm−2) after 5000 bending cycles and the mass density is only 0.35 g cm−3. MnO2 is selected as an electrode active material to explore the role of flexible and conductive paper-based current collectors in supercapacitors. Electrochemical results reveal that the largest areal specific capacitance is 1095 mF cm−2 at 1 mA cm−2 and the excellent electrochemical performance can be attributed to the hierarchical porous fibre structure of paper and the lower contact resistance between the active material and the current collector. Note that the approach can be applied to an enlarged size of metallic conductive paper or textile, presenting a simple and feasible method to fabricate flexible current collectors in a large scale. [ABSTRACT FROM AUTHOR]

A luminescent trimethylamine (TMA) sensor, PTMA-Ir, has been designed and synthesized through immobilizing a phosphorescent iridium(III) complex on a TMA-imprinted polymer. Detailed study shows that the quenching of phosphorescence of PTMA-Ir can serve as a reporter for the binding of TMA on the imprinting sites, thus providing a sensitive, selective, and rapid detection of TMA in both aqueous solutions and gaseous states. Loading PTMA-Ir on filter paper produced a deposition T-Ir, the phosphorescence of which is quenched within 5 s upon exposure to TMA vapor with detection limits of 9.0 ± 0.1 ppm under argon and 15.0 ± 0.1 ppm in an air atmosphere. This work provided an effective method for establishing an imprinting polymer-immobilized luminescent amine sensor. [ABSTRACT FROM AUTHOR]

Nowadays, the goal of carbon peaking and carbon neutrality has become a global consensus, and electrochemical CO2 reduction to provide high-value power fuel is one of the major technical approaches attracting significant research interests and application prospects. However, the inevitable hydrogen evolution reaction in water-based electrolyte systems crowds out the reactive sites of active metals, causing a low CO2 conversion efficiency. In this work, Zn nanosheets were prepared via electrodeposition on the surface of carbon paper and then modified with polytetrafluoroethylene (PTFE) to tune the wetting angle of the electrolyte. A CO faradaic efficiency of 90.2% was achieved for Zn NS-8% PTFE (contact angle: 136.8°) at the electrolytic voltage of −1.0 V vs. RHE along with an overall current density of −7.9 mA cm−2. Experimental results and molecular dynamics simulation revealed that PTFE weakened the aggregation of H2O molecules and was more beneficial for capturing and adsorbing CO2 molecules near the electrode surface. The active sites of hydrogen production were transformed into the reaction center for electrocatalytic CO2 reduction due to the hydrophobicity of the electrode, and the accumulation of the local CO2 concentration accelerated the kinetic activity for electrochemical conversion (CO2 to CO). This strategy of tuning the local environment offers an alternative approach for effective electrode manufacturing in liquid electrolytes. [ABSTRACT FROM AUTHOR]

Leukocyte esterase (LE) is a useful marker that can be used in establishing a diagnosis of urinary tract infections (UTIs). The development of a UTI diagnostic method with quantitative determinations of biomarkers across all age groups is becoming more important. In this report, microfluidic resistance sensors based on silver ink (Ag ink) and silver ink mixed with ZnO nanoparticles (Ag-ZnO ink) were synthesized and coated on cellulose paper, namely LE-Ag-μPADs and LE-Ag-ZnO-μPADs, respectively, for the sensitive detection of LE. The microfluidic design increases the precision of data and further allows for quantitative determination and early detection of LE in human urine. The quantification of LE relies on the change in the resistance readout coating with Ag ink as well as Ag-ZnO ink in the detection zone. A mixture of 3-(N-tosyl- L -alaninyloxy)-5-phenylpyrrole (PE) and 1-diazo-2-naphthol-4-sulfonic acid (DAS) was deposited in the sample zone to selectively recognize LE, and the resulting nonconductive products, i.e., azo compounds, further reacted with the Ag ink and Ag-ZnO ink to increase resistance. The quantitative detectable LE concentrations between 2 to 32 (×5.2 U mL−1), i.e. ≈12 to 108 μg L−1, cover the commercial dipstick range of trace, +1 and +2. The minimum detectable concentration of LE in urine was 1 (×5.2 U mL−1). The lower concentrations of LE detectable by LE-Ag-μPADs (1–8 × 5.2 U mL−1) are below the value achieved with the ELISA LE kit. Urine samples from inpatients with indwelling urinary catheters were used, and the LE levels measured by the present device were highly correlated with those determined by a commercial urine analyser. [ABSTRACT FROM AUTHOR]

The urea oxidation reaction (UOR), which possesses a low theoretical potential and superior kinetics, is an attractive substitute for the anodic oxygen evolution reaction (OER) in overall water splitting; however, the implementation of hydrogen production in overall urea splitting is impeded by the deficiency of highly efficient, durable and cost-effective catalysts. Herein, we fabricated an Ni2P–MoP2 heterostructure with a hierarchical structure grown on carbon paper (Ni–Mo–P/CP), which exhibited robust activity and outstanding durability for the electrocatalytic oxidation of urea. The Ni–Mo–P/CP catalyst possessed an ultralow potential of 1.39 V to obtain the current density of 100 mA cm−2, small Tafel slope (27 mV dec−1) and long-term durability with almost no decay within 15 h. The experimental characterization revealed that the optimized electronic structure and the synergistic effect of abundant exposed active sites in the Ni–Mo–P/CP catalyst contribute to the efficient UOR catalytic activity. This work enriches the candidate catalysts for the UOR and promotes the industrial development of hydrogen production. [ABSTRACT FROM AUTHOR]

Here, we present a new diacetoxy-functionalized UiO-66 metal–organic framework (MOF) for the trace level detection of hydrazine in water. The MOF material (1) was solvothermally prepared by the reaction between ZrOCl2·8H2O and 2,5-diacetoxy-1,4-benzenedicarboxylic acid (H2BDC–(OCOCH3)2). The desolvated material (1′) showed a highly selective fluorescent turn-on signal towards hydrazine in water, which can be visualized by the naked eye under a UV lamp. Within 1 min of hydrazine addition, there was 14-fold fluorescence enhancement. The probe can detect hydrazine up to the nanomolar level (detection limit = 78.8 nM) in water. This detection limit is the lowest among MOF-based fluorescent probes for hydrazine. The material was also utilized for the sensing of hydrazine in paper strips and environmental water samples. Hydrazine-selective deprotection of ester groups anchored with the ligand is the principal reason behind the switch-on nature of sensing. [ABSTRACT FROM AUTHOR]

An effective pathway to cope with the sluggish oxygen evolution reaction (OER) is to accelerate the electron transfer kinetics. Transition metal with high valence states doping can accelerate the reaction kinetics to afford high inherent activity. Herein, a novel trimetallic NiFeCr nanoalloy as an OER electrocatalyst is synthesized by replacing partial Fe in the Ni3Fe alloy with Cr. In the OER process, Cr leached from the surface layer of the NiFeCr alloy to form a core–shell NiFeCr@NiFeOOH structure. The electrons from the OER intermediates were significantly accelerated by the high-valence Cr6+ as an electron acceptor at the core–shell interface. As a result, NiFeCr@NiFeOOH exhibited excellent OER performances with a low overpotential of 209 mV at 25 mA cm−2 in 1.0 M KOH on conductive carbon paper, outperforming the Ni3Fe alloy without Cr doping. Our work provides a new strategy to design and synthesize the NiFe-based alloy with high OER activity. [ABSTRACT FROM AUTHOR]

The document is a contents list for the journal "Dalton Transactions: An International Journal of Inorganic Chemistry." It includes various articles and papers on topics such as molecular transition metal catalysts, spectroscopic techniques, synthesis of materials, and studies on different compounds. The journal aims to connect the global chemistry community and invest its profits back into the field. This document is a list of research papers published in the journal Dalton Transactions. The papers cover a range of topics including electrocatalytic reduction of CO2, assembly of clusters, rechargeable batteries, and carbon nanoarchitectures. Each paper is summarized by its title and authors, providing a brief overview of the research topic. The document is a valuable resource for library patrons conducting research in various scientific fields. [Extracted from the article]

Searching and developing earth-abundant electrocatalysts with predominant activity and favorable stability are significant to resolve increasing environmental pollution and serious energy crisis. In this paper, Mo-based nanowire arrays (NWAs) were synthesized on carbon fiber paper (CFP), and then Ru–MoP NWAs/CFP was successfully assembled through impregnation of Ru and phosphorization. The as-obtained Ru–MoP NWAs/CFP exhibited excellent performance over a broad pH range. As a result, overpotentials of 39.0, 49.9, and 67.1 mV were required to reach the current density of 10 mA cm−2 in 0.5 M H2SO4, 1 M KOH, and 1 M PBS, respectively. The outstanding performance of Ru–MoP NWAs/CFP is mainly related to the introduction of Ru and P atoms, which may enhance the conductivity of the catalyst and develop additional HER active sites. Our work may afford a novel designing approach to develop high performance HER electrocatalysts. [ABSTRACT FROM AUTHOR]

A new microfluidic paper-based analytical device, a (Ag-μPAD)-based chemiresistor composed of silver ink, has been developed for the selective, sensitive, and quantitative determination of nitrite ions in environmental analysis. The silver ink acts as an efficient transducer in terms of resistance changes due to nitrite initiating a diazo reaction and further reacting with the ink. The silver ink is synthesized onto the μPADs by pulsed light sintering from silver nanoparticles, a mixture of silver nanowires and nanoparticles. The resistance changes show two linear response ranges to nitrite in the concentration ranges of 1.0 × 10−8 M to 5.0 × 10−6 M and 1.0 × 10−5 M to 3.2 × 10−3 M, with a limit of detection of 8.5 × 10−11 M (S/N = 3). The sensor displays a wider linear range, a lower detection limit, a higher stability, high selectivity, low-volume sampling, and disposability for nitrite with respect to other nanoparticle- and paper-based sensors. The characterization of silver ink was verified by SEM, EDS, and IR studies, and the sensing mechanism is discussed. In addition, this paper-based sensor has been successfully employed to determine the nitrite content in tap, river and lake water samples. [ABSTRACT FROM AUTHOR]

The fabrication of noble metal free catalysts with excellent performance and high stability by a simple, efficient, general and low-cost approach remains an urgent task for solving the problem of resource shortage. Herein, Cu-based metal organic frameworks (MOFs) immobilized on commercial filter papers were used as pyrolysis precursors to synthesize CuxO@C at various calcination temperatures. Notably, the resultant CuxO@C-400 exhibits an excellent catalytic performance toward the reaction of reducing 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). By virtue of the large specific surface area, well-developed porosity, good stability and high dispersity of CuxO nanoparticles, the obtained CuxO@C-400 could complete the reduction reaction within 11 min with a large apparent rate constant κapp value (4.8 × 10−3 s−1). Our strategy therefore opens a new avenue for the preparation of low-cost and high-performance noble metal free catalysts. [ABSTRACT FROM AUTHOR]

This document is a contents list for the journal "Dalton Transactions: An International Journal of Inorganic Chemistry." It provides a list of articles published in the journal, covering various topics in inorganic chemistry. The journal is published by The Royal Society of Chemistry, a reputable chemistry community. The document includes research papers on topics such as catalysis, spin state switching, targeted therapy for breast cancer, and photocatalysis. It also includes an expression of concern and a correction for previous papers. [Extracted from the article]

The document is a contents list for the journal "Dalton Transactions: An International Journal of Inorganic Chemistry." It includes the titles and authors of various articles published in the journal, covering topics such as sulphur spectrum of trivalent lanthanoid oxysulphides, magnetic relaxation in manganese coordination compounds, CO2 absorption/desorption properties, and more. The journal is published by The Royal Society of Chemistry, a leading chemistry community. The papers in this journal cover a wide range of topics in inorganic chemistry, including battery technology, catalysis, materials science, and theoretical analysis of metal complexes. These papers provide valuable insights into scientific phenomena and offer potential applications in various fields. [Extracted from the article]

This document is a contents list for the journal "Dalton Transactions: An International Journal of Inorganic Chemistry." It provides a list of papers published in the latest issue of the journal, covering a wide range of topics in chemistry. The papers explore subjects such as stimuli-responsive luminescence, the synthesis and reactivity of different compounds, and the development of new sensors, luminescent materials, catalysts, and coordination compounds. The journal aims to foster connections within the global chemistry community and reinvest its profits into the field. Additionally, the document includes a correction for a previous paper. [Extracted from the article]

This document is a contents list for the journal "Dalton Transactions: An International Journal of Inorganic Chemistry." It features a compilation of research papers covering various topics such as metal dioxo complexes, piezo-photocatalytic CO2 reduction, and carbonaceous materials for lithium-ion batteries. The journal aims to foster connections within the chemistry community and stimulate innovative ideas. Additionally, the document includes corrections to two previously published papers. [Extracted from the article]

The document is a contents list for the journal "Dalton Transactions: An International Journal of Inorganic Chemistry." It includes various articles and papers on topics such as copper complexes, lanthanide-based POMs, and coordination polymers. The journal is published by The Royal Society of Chemistry, a leading chemistry community. The document also mentions approved training courses offered by the society. The given document is a list of papers published in the journal Dalton Transactions. The papers cover a range of topics in chemistry, including catalysis, phosphors, materials synthesis, and more. Each paper is identified by its title, authors, and page number. The document also includes a correction and a retraction for two previously published papers. [Extracted from the article]

Ti2AlC has been investigated for several decades, but much less attention has been paid to its delamination and potential energy storage applications, mainly due to the difficulty of delamination and its oxidation features. Herein, a new path to enhance exfoliation and delamination of two-dimensional (2D) Ti2CTx MXene is used. By using an etchant of HCl + LiF, multilayer Ti2CTx is easy to obtain. With only the assistance of mild sonication for 1.5 h without any additional intercalation, two-dimensional (2D) Ti2CTx flake suspensions are produced. Subsequently, the as-fabricated stable suspensions of delaminated Ti2CTx flakes are combined with carbon nanotubes. After filtration, a two-dimensional layered Ti2CTx/carbon nanotube (CNT) nanocomposite “paper” is prepared. Owing to the larger specific area of MXene flakes, which is caused by the complete exfoliation of MXene, with carbon nanotubes assisting with structural support between layers to prevent restacking, this structure provides a rapid charge transfer path during electrochemical reactions. When the nanocomposite paper is used as a lithium ion battery anode, it exhibits a higher capacitance and better cycling stability (a reversible capacity of 155.5 mA h g−1 at 100 mA g−1 after 200 cycles). Moreover, the “paper” can be directly used for electrodes in supercapacitors; the calculated capacitances are 515.3 F g−1 and 694 F cm−3 at a scanning rate of 2 mV s−1. The facile synthesis of layered Ti2C MXene/carbon nanotube nanocomposite paper provides a more secure and easy way to fabricate promising energy storage materials, and creates wider opportunities for exploiting the potential of other MXenes. [ABSTRACT FROM AUTHOR]

In this work, we present a Ag@Au nanoprism-metal–organic framework-paper based glucose sensor for rapid, sensitive, single-use and quantitative glucose determination in human serum. To achieve painless measurement of glucose with a non-invasive detection methodology, this biosensor was further tested in human urine. In this approach, a new hybrid-Ag@Au nanoprism loaded in close proximity to micrometer sized coordination polymers as phosphorescent luminophores significantly enhanced the emission intensity due to metal-enhanced phosphorescence and worked as reaction sites to support more dissolved oxygen. Reports of enhanced phosphorescence intensity are relatively rare, especially at room temperature. The true enhancement factor of Ag@Au-phosphorescent metal–organic frameworks on paper was deduced to be 110-fold, making it a better optical type glucose meter. The results demonstrate the validity of the intensity enhancement effect of the excitation of the overlap of the emission band of a luminophore with the surface plasmon resonance band of Ag@Au nanoprisms. Ag@Au nanoprisms were used not only to improve the detection limit of glucose sensing but also to extend the glucose sensing range by enhancing the oxygen oxidation efficiency. The oxidation of glucose as glucose oxidase is accompanied by oxygen consumption, which increases the intensity of the phosphorescence emission. The turn-on type paper-based biosensor exhibits a rapid response (0.5 s), a low detection limit (0.038 mM), and a wide linear range (30 mM to 0.05 mM), as well as good anti-interference, long-term longevity and reproducibility. Finally, the biosensor was successfully applied to the determination of glucose in human serum and urine. [ABSTRACT FROM AUTHOR]

Introducing the sophisticated morphologies and structures of natural substances into artificial materials provides a promising strategy for the fabrication of functional materials with tailored structures and functionalities. Herein, our recent advances achieved in the fabrication of hierarchically structured functional materials derived from natural cellulose substances (e.g., ordinary laboratory filter paper) for lithium-ion batteries are reviewed. The surface sol–gel process was employed to fabricate metal oxides (Sn, Ti, Fe, etc.), silica and silicon based nanocomposites by using the corresponding metal alkoxides as the precursors, which faithfully inherited the unique porous network structures of the initial cellulose substances. However, the nanomaterials synthesized as such are limited to the above-mentioned species due to the limitation of specific metal alkoxide precursors used. To break this limitation, specific polyoxometalate clusters were employed as the building blocks to be assembled onto the surfaces of cellulose nanofibres and eventually to obtain the corresponding molybdenum based nanomaterials with three-dimensional porous network structures and specific properties. These cellulose derived nanocomposites exhibit improved lithium storage capacities and cycling stabilities when applied as anodic materials for lithium-ion batteries, resulting from the unique hierarchically porous network structures inherited from the initial cellulose substance and the strong synergistic interactions among the components contained therein. [ABSTRACT FROM AUTHOR]

The document is a contents list for the journal "Dalton Transactions: An International Journal of Inorganic Chemistry." It includes various articles and papers on topics such as combatting bacterial infections, rare-earth metal-organic frameworks, and electrochemical capacitor applications. The journal is published by The Royal Society of Chemistry, a leading chemistry community. The document provides a brief overview of the articles included in the journal issue. The papers cover a range of topics in chemistry, including the synthesis of stable cyclopropenylvinyl ligands, the properties of metal-organic frameworks, the photocatalytic performance of titanium-oxide clusters, and the adsorption mechanisms of heavy metals on silica. Other topics include the synthesis of coordination polymers, the synthesis of salophen complexes, and the behavior of cyanido-bridged complexes. The papers provide valuable insights into various areas of chemical research. [Extracted from the article]

This document is a contents list for the journal "Dalton Transactions: An International Journal of Inorganic Chemistry." It features articles and papers on various topics, including plasma technology for supercapacitor electrode materials, bioinspired oxidation reactions, and the synthesis of metal-organic framework-based composites. Published by The Royal Society of Chemistry, the journal aims to connect the world with the chemical sciences. The document includes articles discussing a method for creating a layered cladding structure on carbon nanofibers for use in dye-sensitized solar cells, the effect of coordinated anions on ferromagnetically coupled single-molecule magnets, and a correction to a previous article about copper catalysts. The document was published in 2024. [Extracted from the article]

Photosystem I/dithiol molecular wire/nanoparticle bioconjugates have been shown to photocatalytically generate dihydrogen at linear rates when continuously illuminated. In an effort to maximize H2production, the pH and ionic concentration of the solution, the mobility of the electron donor, the length and degree of saturation of the molecular wire, and the intensity of the light were systematically investigated. Optimal conditions included a solution buffered at pH 6.0, cross-linked plastocyanin, rebuilt spinach PS I, and the use of 1,4-benzenedithiol to connect PS I to the Pt nanoparticle. Illumination of this optimized Photosystem I/dithiol molecular wire/nanoparticle bioconjugate at a light intensity of 70 μE m−2s−1generated a measured one time H2production rate of 312 μmol H2mg Chl−1h−1. [ABSTRACT FROM AUTHOR]

The lanthanide metal organic framework compounds [Ln(BPTA)1.5(Bpy)]·0.5DMF (Ln = Y, Eu, Gd, Tb, Dy; 1a–5a) and [Ln(BPTA)1.5(Phen)]·0.5DMF (Ln = Y, Eu, Gd, Tb, Dy; 1b–5b) were prepared by employing 2,5-bis(prop-2-yn-1-yloxy)terephthalic acid (2,5-BPTA) as the primary ligand and 2,2′-bipyridine (1a–5a) and 1,10-phenanthroline (1b–5b) as the secondary ligands. Single-crystal structural studies on [Gd(BPTA)1.5(Bpy)]·0.5DMF (3a) and [Dy(BPTA)1.5(Phen)]·0.5DMF (5b) indicated that the compounds have a two-dimensional structure. The Y compound exhibits blue emission, and the other compounds exhibit emission in the expected regions (λex = 350 nm). White light emission was achieved by careful mixing of the red (Eu3+) and green (Tb3+) components in the blue emitting Y compound. Thus, Y0.96Tb0.02Eu0.02 (bpy) and Y0.939Tb0.06Eu0.001 (phen) were found to show white emission when excited using a wavelength of 350 nm. The introduction of N–N-containing ancillary ligands (i.e., bpy and phen) increased the overall quantum yield (QY) of white light emission to 31% and 43%, respectively. The high QY observed for the Tb and Eu compounds was found to be sensitive and selective for the fluorometric detection of azinphos-methyl pesticide and trinitrophenol (TNP) in an aqueous medium at the ppb level. The same behaviour was observed when utilising the compounds as onsite paper strip sensors. Their magnetic properties were also studied, revealing for the Tb and Dy derivatives slow relaxation of the magnetisation at low temperature. The present study highlights the usefulness of rigid π-conjugated molecules such as 2,2′-bipyridine and 1,10-phenanthroline in enhancing the many utilities of rare-earth-containing MOFs towards white light emission, the sensing of harmful and dangerous substances and magnetic properties. [ABSTRACT FROM AUTHOR]

Ligating properties of a tripodal, potentially tetradentate aminetris(phenol) ligand, tris(2-hydroxy-3,5-di-tert-butylbenzyl)amine, H3L, containing [N,O,O,O] donor atoms toward the vanadium ions in +iiiand ivoxidation states have been studied. The structures of complexes 1[LVIII(CH3OH)]0, 2[LVIV(OCH3)]0and 3[LVIV(acac)]0were determined by X-ray diffraction methods as having five-coordinate V(iii), 1, five-coordinate non-oxo-vanadium(iv), 2, and six-coordinate non-oxo-vanadium(iv) 3, respectively. Compounds 1–3were also studied with electrochemical methods, variable-temperature (2–295 K) magnetic susceptibility measurements and X-band electron paramagnetic resonance (EPR) spectroscopy. The electrochemical results of 2and 3suggest metal-centered oxidation, i.e.the generation of a VV-phenolate species. EPR investigations indicate a (dxy)1ground state showing a considerable increase in the in-plane π-bonding, as is expected for a phenolate ligand. [ABSTRACT FROM AUTHOR]

2-Aminomethylaniline was converted into the N,N′-bis(pivaloyl) (1) or -bis(trimethylsilyl) (2) derivative, using 2 ButC(O)Cl or 2 Me3SiCl ( RCl), respectively, with 2 NEt3, or for 2from successively using 2 LiBunand 2 RCl. N,N′-Bis(neopentyl)-2-(aminomethyl)aniline (3) was prepared by LiAlH4reduction of 1. From 2or 3and 2 LiBun, the appropriate dilitiodiamide {2-[{N(Li)R}C6H4{CH2N(Li)R}(L)]2(L absent, 4a; or L = THF, 4b) or the N,N′-bis(neopentyl) analogue (5) of 4awas prepared. Treatment of 4awith 2 ButNC, 2 (2,6-Me2C6H3NC) or 2 ButCN ( L′) furnished the corresponding adduct [2-N{Li(L′)R}C6H4{CH2N(Li)R}] (4c, 4dor 4e, respectively), whereas 4bwith 2 PhCN afforded [2-{N(Li)R}C6H4{CH2C(Ph) = NLi(NCPh)}] (6). The dimeric bis(amido)stannylene [Sn{N(R)C6H4(CH2NR)-1,2}]2(7) was obtained from 4aand [Sn(μ-Cl)NR2]2, while the N,N′-bis(neopentyl) analogue 8of 7was similarly derived from [Sn(μ-Cl)NR2]2and 5. Reaction of two equivalents of the diamine 2with Pb(NR2)2yielded 9, the lead homologue of 7. Oxidative addition of sulfur to 7led to the dimeric bis(diamido)tin sulfide 10. Treatment of 2successively with ‘MgBu2’ in C5H12and THF gave [Mg{N(R)C6H4(CH2NR)}(THF)]2(11a), which by displacement of its THF by an equivalent portion of ButCN or PhCN produced [Mg{N(R)C6H4(CH2NR)}(CNR')n] [R′ = But, n= 1 (11b); R′ = Ph, n= 2 (11c)]. The Ca (12), Sr (13) or Ba (14) analogues of the Mg compound 11awere isolated from 2and either the appropriate compound M(NR2)2(M = Ca, Sr, Ba), or successively 2 LiBunand 2 M(OTos)2. The new compounds 1–14were characterized by microanalysis (C, H, N; not for 1, 2, 3, 5), solution NMR spectra, νmax(CN) (IR for 4c, 4d, 4e, 6, 11b, 11c), selected EI-MS peaks (for 1, 2, 3, 7, 8, 9, 10), and single crystal X-ray diffraction (for 4a, 4b, 11a). [ABSTRACT FROM AUTHOR]

Ligand–metal cooperation in iridium and platinum complexes bearing tricyclic dibenzobarrelene-based PC(sp3)P pincer ligands is discussed. We demonstrated that the carbon–metal bond in these complexes may be efficiently cleaved and regenerated via1,2-addition/elimination reactions. [ABSTRACT FROM AUTHOR]

The kinetics of reaction between the [Mo3M′S4(H2O)10]4+clusters (M′ = Pd, Ni) and H3PO3has been studied in 4.0 M Hpts/Lipts (pts−= p-toluenesulfonate). For both complexes there is an initial kinetic step with small absorbance changes that corresponds to substitution of the water coordinated to Pd by a molecule of tetrahedral H3PO3. For the Pd complex, tautomerization of H3PO3occurs in a slower kinetic step with much larger absorbance changes; it leads to formation of [Mo3Pd(pyr-H3PO3)S4(H2O)9]4+in which H3PO3adopts a pyramidal structure, but the process is not as favored as for H3PO2. The kinetics of this second step is independent of the concentration of H3PO3but dependent on the concentration of Hpts on the supporting electrolyte. For the Ni complex, the second step is severely hindered and its kinetics could not be studied. DFT calculations indicate that tautomerization of H3PO3is expected to be less favoured than that of H3PO2, both processes being less favored at the Ni cluster than at its Pd analogue. With regard to the tautomerization mechanism, the calculations indicate that the mechanism previously proposed for H3PO2can be the same for H3PO3, although the initial H-shift can also occur through a protonation–deprotonation sequence with participation of external protons instead of a second molecule of the phosphorus acid. TD-DFT studies have been also carried out to understand the similarity between the spectra of the starting complex and the reaction intermediate formed in the first kinetic step as well as the large spectral changes associated to the tautomerization process. Although it contains contributions from several transitions, the intense band observed for clusters containing coordinated pyr-H3PO3involves essentially ligand-to-metal charge-transfer (LMCT) transitions. [ABSTRACT FROM AUTHOR]

Eleven new lanthanide oxalatophosphonate hybrids with a 2D layered structures, namely, [Ln(H3L)(C2O4)]·2H2O (Ln = La–Dy, Er and Y, H4L = C6H5CH2N(CH2PO3H2)2), have been synthesized under hydrothermal conditions and structurally characterized by X-ray single-crystal diffraction, X-ray powder diffraction, infrared spectroscopy, elemental analysis and thermogravimetric analysis. Compounds 1–11are isomorphous and they exhibit a 2D framework structure. Two {LnO8} polyhedra and four {CPO3} tetrahedra are interconnected into a unit viacorner-sharing, and the so-built units are bridged by the oxalate anions into a layer. The result of connections in this manner is the formation of a 24-atom window. The thermal stabilities and guest desorption–sorption properties of compounds 1–11have been investigated. The luminescent properties of compounds 5, 6, 8and 9have also been studied. [ABSTRACT FROM AUTHOR]

The synthesis of novel heterobimetallic derivatives of general formula [RuClCp(PPh3)-μ-dmoPTA-1κP:2κ2N,N′-M(acac-κ2O,O′)2] (M = Ni (3), Zn (4); dmoPTA = 3,7-dimethyl-1,3,7-triaza-5-phosphabicyclo[3.3.1]nonane) is described. The preparations of the ruthenium–cobalt analogue (M = Co (2)) and the starting compound [RuClCp(HdmoPTA-κP)(PPh3)](CF3SO3) have been revised and their yield improved. Similar to 2, the solid state structures of 3and 4show that the dmoPTA-P and the dmoPTA-NCH3atoms are involved in the coordination to the {RuCpCl(PPh3)} and {M(acac)2} moieties, respectively. The size of the diffusing units is almost the same for the three binuclear complexes, indicating that they exhibit similar solution structures. The diamagnetic ruthenium–zinc derivative was fully characterized in solution at 193 K by NMR as two diastereomeric pairs of enantiomers (R-Ru, Δ-Zn; R-Ru, Λ-Zn; S-Ru, Δ-Zn; S-Ru, Λ-Zn). Finally, the electrochemical properties of the complexes have been investigated by cyclic voltammetry. [ABSTRACT FROM AUTHOR]

Trialkyl imido niobium and tantalum complexes [MR3(NtBu)] (M = Nb, R = Me 2, CH2CMe33, CH2CMe2Ph 4, CH2SiMe35; M = Ta, R = Me 6, CH2CMe2Ph 7, CH2SiMe38) have been prepared by treatment of solutions containing [MCl3(NtBu)py2] (M = Nb 1a, Ta 1b) with three equivalents of magnesium reagent. By an unexpected hydrolysis reaction of the tris-trimethylsilylmethyl imido tantalum compound 8a, a μ-oxo derivative [(Me3SiCH2O)(Me3SiCH2)3Ta(μ-O)Ta(CH2SiMe3)2(NtBu)] (8a) was formed and its structure was studied by X-ray diffraction methods. Reactions of trialkyl imido compounds with two equivalents of isocyanide 2,6-Me2C6H3NC result in the migration of two alkyl groups, leading to the formation of a series of alkyl imido bisiminoacyl derivatives [MR(NtBu){C(R)NAr}2] (Ar = 2,6-Me2C6H3; M = Nb, R = Me 9, CH2CMe310, CH2CMe2Ph 11, CH2SiMe312, CH2Ph 13; M = Ta, R = CH2CMe314, CH2CMe2Ph 15, CH2SiMe316). All compounds were studied by IR and NMR (1H, 13C and 15N) spectroscopy. [ABSTRACT FROM AUTHOR]

Twelve Pt(ii) complexes with cis-PtP2S2pharmacophores (where P2refers to two monodentate or one bidentate phosphane ligand and S2is a dithiolato ligand) were prepared, characterized and evaluated as potential antiproliferative agents. The various compounds were first studied from the structural point of view; afterward, their solubility properties as well as their solution behaviour were analyzed in detail. Antiproliferative properties were specifically evaluated against A2780 human ovarian carcinoma cells, either resistant or sensitive to cisplatin. For comparison purposes similar studies were carried out on four parent cis-dichloro bisphosphane Pt(ii)complexes. On the whole, the cis-PtP2S2compounds displayed significant antiproliferative properties while the cis-PtP2Cl2(cis-dichloro bisphosphane Pt(ii)) compounds revealed quite poor biological performances. To gain further insight into the molecular mechanisms of these bisphosphane Pt(ii) compounds, the reactions of selected complexes against the model protein cytochrome c were investigated by ESI-MS and their adduct formation explored. A relevant reactivity with cyt c was obtained only for cis-PtP2Cl2compounds, whereas cis-PtP2S2compounds turned out to be nearly unreactive. The obtained results are interpreted and discussed in the frame of the current knowledge of anticancer platinum compounds and their structure–activity-relationships. The observation of appreciable antiproliferative effects for the relatively inert cis-PtP2S2compounds strongly suggests that these compounds will undergo specific activation within the cellular environment. [ABSTRACT FROM AUTHOR]

Pseudooctahedral complexes [MCl3(NtBu)L2] (M = Nb, L = py 1, ½ tmeda 3; M = Ta, L = py 2, ½ tmeda 4) have been studied by spectroscopic methods. By a VT 1H NMR experiment a mutual exchange process between the pyaxand pyfreein the complexes 1–2was observed, whereas 13C and 15N NMR studies showed in the complexes 3–4a tmeda ligand with an axial/equatorial coordination mode. The reaction of 2with 3 equiv of Grignard reagent produces the methathesis products [TaR3(NtBu)] (R = CH2CMeCH25, CH2CHCHCH36) in which 2-methylallyl and 2-butenyl groups appear with a η3- and σ-coordination mode, respectively. When, toluene solutions of the compounds 5–6were treated with 2 equiv of 2,6-dimethylphenylisocyanide the imido bisiminoacyl compounds [TaR(NtBu){C(R)NAr-κ1C}2] (Ar = 2,6-Me2C6H3; R = CH2CMeCH27, CH2CHCHCH38) can be isolated, viaan imido iminoacyl intermediate [TaR2(NtBu){C(R)NAr-κ1C}] (Ar = 2,6-Me2C6H3; R = CH2CMeCH29) as we have observed in the treatment of 5with 1 equiv of isocyanide; however, the analogous reaction between 5and COPh2leads to the formation of the trisalkoxo imido compound [Ta(OCPh2R)3(NtBu)] (R = CH2CMeCH210). All new complexes were studied by IR and multinuclear NMR spectroscopy. [ABSTRACT FROM AUTHOR]

A new synthetic methodology for the catalytic C–H functionalisation of 2-pyrones is described which proceeds regioselectively at the C3 position, mirroring the observed regioselectivity in 6π-electrocyclisation/oxidative aromatisation reactions of related compounds. Insight into the reaction mechanism is provided, with support for a neutral palladium(ii) pathway. Cationic palladium(ii) complexes possessing 2-pyrones are unstable and readily undergo PdII→P transfer at ambient temperature resulting in phosphonium salt formation (and Pd0Lnspecies). [ABSTRACT FROM AUTHOR]

Two {Co3+–Zn2+} heterobimetallic coordination networks have been synthesized utilizing Co3+complex as the building blocks. The structural studies reveal 2D sheet-like networks where the Co3+containing building blocks are connected through Zn2+ions. Two different building blocks generate two unique networks as evidenced by the crystallographic studies and other properties. These networks are shown to catalyze Lewis metal ion assisted Strecker reaction in heterogeneous manner. [ABSTRACT FROM AUTHOR]

The potential energy surfaces of the reactions of Cl4MCH2(M = Cr, Mo, W, Ru, Re) with ethylene, models of potential chain-carrying catalysts and olefins respectively in the transition metal-catalyzed olefin metathesis reaction, have been explored using density functional theory at the B3LYP/LACVP* level of theory. In Cl4MCH2(M = Cr, Ru), the carbenoid complexes Cl3MCH2–Cl have been found to be more stable than the corresponding carbene Cl4MCH2complexes whereas in Cl4MCH2(M = Mo, W, Re) the carbene complexes are more stable than the carbenoid complexes. The carbenoid complexes have been found not to favor the formation of metallacyclobutanes, a key step in the olefin metathesis reaction according to the Herrison–Chauvin mechanism, indicating that the active species for the metathesis reaction is a carbene complex and not a carbenoid complex. Therefore, even though the formation of metallacyclobutanes through formal [2+2] cycloaddition has been found to be a low-barrier process with each of the metal carbene complexes investigated, metathesis is likely to occur only in Cl4MCH2(M = Mo, W, Re) but not in Cl4MCH2(M = Cr, Ru) since the reaction surface in the latter complexes is likely to be populated by the carbenoid complex rather than the carbene complex. In Cl4WCH2the kinetic and thermodynamic preference of the productive [2+2] pathway leading to the metallacyclobutane over the [3+2] pathway is unambiguous whereas in Cl4MoCH2the [3+2] pathway is likely to be competitive with the [2+2] pathway. The metallacyclobutane formation in W and Re has been found to have lower barriers than in Mo, suggesting that the W and Re complexes may have a greater metathesis activity than the Mo complex. [ABSTRACT FROM AUTHOR]

X-Ray crystal structures, and calculated structures (at B3LYP/6-31G level) are reported for seven N-arylbenzazoles (two carbazoles, indoles and benzimidazoles, and one indazole) bearing electron withdrawing groups in the 2-position of the N-aryl ring. The structures are markedly non-planar by rotation around the N-aryl bond, with the substituent in most cases lying s-Ein relation to the N-aryl bond; intermolecular electrostatic interactions in the crystal rationalise the two examples in which an s-Zconformation is observed. A large interplanar angle between the benzazole and the N-aryl planes is associated with a small interplanar angle between the planes of the N-aryl group and the substituent and vice versa. [ABSTRACT FROM AUTHOR]

Improved methods of analysis and new quantum chemical calculations have been applied to the results of earlier gas-phase electron diffraction (GED) studies of digallane to give what is judged to be the most realistic structure available to date. The principal distances (ra3,1in pm) and interbond angles (∠a3,1in deg) are as follows (t= terminal, b= bridging): r(GaGa) 254.9(2), r(Ga−Ht) 155.0(6), r(Ga−Hb) 172.3(6), ∠Ga−Hb−Ga 95.4(5), and ∠Ht−Ga−Ht128.6(9). Scrutiny of the IR spectra of solid Ar matrices doped with the vapour above solid samples of gallane at temperatures in the range 190-220 K reveals the presence of not only Ga2H6as the major component, but also a significant fraction of the monomer GaH3. Analysis of the relative proportions of the two molecules evaporating from the solid at different temperatures has led to a first experimental estimate of 59 ± 16 kJ mol−1for the enthalpy change associated with the reaction Ga2H6(g) → 2GaH3(g). Together with a value of 52 kJ mol−1delivered by fresh calculations at the MP2 level, this implies that the stability of the dimer with respect to dissociation has been overrated by earlier theoretical treatments. [ABSTRACT FROM AUTHOR]

Homoleptic cationic benzimidazole-imidazolin-2-ylidene N-heterocyclic carbene (NHC = L) complexes of NiIIand PdIIhave been prepared directly from the ligand precursor in salt form [H.L]Cl and from the transmetallation route viaAgI. The N-tether of the imidazolinylidene ring imposes a significant influence on the nuclearity of the intermediate Ag(i)-NHC complexes and the geometric isomer outcome of the d8products. Use of a benzyl-substituted NHC gives [Ag4(LBn)2Cl4], 2a(from [HLBn]Cl, 1a, and Ag2O) (Bn = benzyl), which shows an alignment of four silver atoms bridged by the difunctional C–N ligands and chlorides. Its transmetallation with NiCl2(PPh3)4and PdCl2(MeCN)2results in double-metal salts 2[M(LBn)2]2+[Ag4Cl8]4−(M = Ni (3a) and Pd (4a)). The nuclearity of the Ag4aggregate is maintained in the transmetallation process. Their Ag-free forms [M(LBn)2]Cl2(M = Ni (5) and Pd (6)) were prepared by direct deprotonation of 1awith M(OAc)2. The two carbenic carbon donor are cis- to each other in both 3aand 4a, thus imposing the weaker σ-benzimidazole nitrogen donor to be transto them. A sterically demanding mesityl pendant however gives the dinuclear dissymmetic [Ag2(LMes)2Cl2], 2b(Mes = mesityl) that shows a 12-membered metallomacrocyclic ring with a 2-coordinated [AgI(NHC)2] and 4-coordinated [AgI(Imd)2Cl2] (Imd = imidazole). Transmetallation of the latter, or direct metallation from [HLMes]Cl, 1b, gives [M(LMes)2]Cl2(M = Ni (3b) and Pd (4b)) with the two carbonic carbon transto each other. The catalytic potential of 3band 4b, which are more effective than 5and 6, has been demonstrated by their high activities in Ni-catalyzed Kumada at room temperature and Pd-catalyzed Heck couplings of aryl and/or heteroaryl halides, respectively. [ABSTRACT FROM AUTHOR]

The structures and magnetic properties of a family of new octanuclear heterometallic 3d-4fcomplexes [MnIII4LnIII4(μ3-OH)4(μ2,η1-X)4(O2CBut)8(t-bdea)4]·solv, where X = N3−, Ln = Y (1), Eu (2), Gd (3), Tb (4), Dy (5), Ho (6); X = OCN−, Ln = Dy (7); X = NO3−, Ln = Gd (8), Tb (9), Dy (10), Ho (11), Er (12); solv = MeCN or toluene, are reported. The metal topology in the aggregates can be described as consisting of a “Ln4-square inscribed in a Mn4-square”. Complexes 1-7are prepared by the reactions of t-butyldiethanolamine (t-bdeaH2) with a preformed hexanuclear manganese pivalate complex [Mn6], the respective lanthanide salt and either NaN3or NaNCO, while 8-12are obtained from the direct reaction of Mn(OAc)2, Ln(NO3)3·xH2O and t-butyldiethanolamine. The magnetic properties of all the complexes were investigated using variable temperature magnetic susceptibility and magnetisation measurements. Similar magnetic behaviour was observed for compounds containing the same lanthanide, indicating that changing the bridging ligand X does not have a significant effect on the magnetic behaviour. The TbIIIand DyIIIcompounds 4, 5, 7, 9and 10all show frequency-dependent acsusceptibilities indicative of a slow relaxation of magnetisation and are therefore considered as Single-Molecule Magnets. [ABSTRACT FROM AUTHOR]

The role of the NH3ligands in the highly successful antitumour agents cisplatin and carboplatin is not fully understood. Suggestions that the ammonia ligands are involved in target recognition through hydrogen bond formation, e.g.with guanine-O6, have been questioned. Here, we review the roles and functions of NH3ligands of cis-PtCl2(NH3)2and likewise of its trans-isomer in complexes with model nucleobases as well as other N-heterocyclic ligands. Specifically, their roles in hydrogen bonding interactions with nucleobases as well as anions, the influence on acid–base properties of co-ligands, their involvement in condensation reactions, as well as a variety of displacement reactions will be examined. As a result, it can be stated that the ammonia ligands in cis- and trans-PtII(NH3)2entities display additional features to those generally discussed in the last four decades since the discovery of the antitumour activity of cisplatin. [ABSTRACT FROM AUTHOR]

Two isomorphous 3D Mn(II) and Co(II) coordination polymers with a dicarboxylate inner salt and cyanate as coligands were synthesized and structurally characterized, and their magnetic properties have been studied. In the compounds, [M(L)(NCO)]n·nH2O (M = Mn, Co, L = 1-carboxymethylpyridinium-4-carboxylate), neighboring metal ions are linked by the 3-fold bridges of an end-on cyanate and two syn–syncarboxylate bridges to give an anionic chain of [M(µ-NCO)(µ–COO)2]n, and each chain is interlinked to four other chains by the cationic 1-methylpyridinium spacers to generate a 3D structure with the 42· 63· 8 net topology. They are the first compounds with mixed cyanate and carboxylate bridges. Magnetic studies reveal that the 3-fold mixed bridge propagates antiferromagnetic coupling in the Mn(II) compound but ferromagnetic coupling in the Co(II) compound. The rather complex magnetic behaviors of the Co(II) compound are analyzed taking into account the first-order spin-orbital coupling and the intrachain ferromagnetic interactions. [ABSTRACT FROM AUTHOR]

An electrospray ionization mass spectrometer equipped with a quadrupole ion trap as the mass analyzer provided a powerful tool for the investigation of metal ligand affinities of catalysts for atom transfer radical polymerization. It allowed, in particular, (i) the identification, in a library of ligands, of the most stable, and thus active, copper catalysts; (ii) the assessment of the effects of the reaction medium on the relative stabilities of the catalyst complexes; and (iii) the evaluation of the influence of the nature of the ligand on both the complex halogenophilicity and the metal–ligand stabilities in the gas-phase. [ABSTRACT FROM AUTHOR]

The loading of pre-treated amorphous silica with platinum or palladium was carried out by using the molecular precursors Pt2(μ-Cl)2Cl2(CO)2, or Pd2(μ-Cl)2Cl2(CO)2, respectively, which contain the required amount of coordinated CO to carry out the formation of the metal particles upon contact with moisture. The reactivity of the well-soluble mononuclear platinum complex cis-PtCl2(CO)2with stoichiometric amounts of water was investigated either under N2or CO. The metal nanoparticles produced on the silica matrix have been characterized by X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The catalytic performance of the silica-supported metals thus produced was evaluated in the hydrogenation of cyclohexene. [ABSTRACT FROM AUTHOR]