Pd Center Research Articles

Control of Interlocking Mode in Pd4L8 Cage Catenanes.

Precise control over the catenation process in interlocked supramolecular systems remains a significant challenge. Here, we report a system in which a lantern-shaped Pd2L4 cage can dimerize to form two distinct Pd4L8 catenanes with different interlocking degree: a previously described quadruply interlocked double cage motif of D4 symmetry and an unprecedented triply interlocked structure of C2h symmetry. While the former structure features a linear arrangement of four Pd(II) centers, separated by three mechanically linked pockets, the new motif has a staggered shape. Both assemblies are topological isomers, coexisting in equilibrium in solution. The triply interlocked species is thermodynamically more stable due to extended noncovalent interactions between the ligands, as supported by X-ray structure analysis and electronic structure calculations. Notably, the degree of interlocking in the double cage system can be controlled by a change of temperature and through anion exchange. Cage-to-cage transformations were followed by NMR, MS and TIMS methods.

Control of Interlocking Mode in Pd4L8 Cage Catenanes

Precise control over the catenation process in interlocked supramolecular systems remains a significant challenge. Here, we report a system in which a lantern‐shaped Pd2L4 cage can dimerize to form two distinct Pd4L8 catenanes with different interlocking degree: a previously described quadruply interlocked double cage motif of D4 symmetry and an unprecedented triply interlocked structure of C2h symmetry. While the former structure features a linear arrangement of four Pd(II) centers, separated by three mechanically linked pockets, the new motif has a staggered shape. Both assemblies are topological isomers, coexisting in equilibrium in solution. The triply interlocked species is thermodynamically more stable due to extended noncovalent interactions between the ligands, as supported by X‐ray structure analysis and electronic structure calculations. Notably, the degree of interlocking in the double cage system can be controlled by a change of temperature and through anion exchange. Cage‐to‐cage transformations were followed by NMR, MS and TIMS methods.

Stereoselective Preparation and Pd-catalyzed Suzuki-Miyaura Cross-coupling of Alkenyl Sulfoximine.

Although numerous transition-metal catalyzed cross-coupling reactions of alkenyl electrophiles with a sulfur(VI) leaving group, mainly alkenyl sulfones, have been developed, most rely heavily on highly nucleophilic Grignard reagents, and the use of organoboron reagents remains challenging. We report herein facile preparation and the following Pd-catalyzed Suzuki-Miyaura cross-coupling reaction of alkenyl sulfoximine, a monoaza analog of sulfone. The condensation of alkyl sulfoximine with aldehydes, developed in this study, makes alkenyl sulfoximines more readily available. The resulting alkenes undergo an unprecedented oxidative addition of the C-S bond to the Pd center. This cross-coupling proceeds with retention of its original stereochemistry and provided alkenes bearing three different functionalities in a stereoselective fashion. DFT calculations highlight the critical role of boronic acid, rather than boronic ester, in facilitating this transformation.

Amphiphilic palladium NHC-complexes with chelating bis-NHC ligands based on imidazole-4,5-dicarboxylic acid: synthesis and catalysis in water.

Efficient catalytic systems for various organic transformations in green solvents, especially water, are in great demand. Catalytically active bis-NHC complexes of palladium(II) based on imidazole-4,5-dicarboxylic acid with different lipophilicities were obtained. The synthesis of imidazolium salts was complicated by the formation of side products of nucleophilic substitution by iodide ions in the Menshutkin reaction involving alkyl iodides, which was successfully resolved by using alkyl tosylates. The synthesis of bis-NHC complexes of palladium(II) was carried out in situ using Pd(OAc)2 and KI from imidazolium tosylate salts. The structures of all compounds were well-characterized by a complex of modern physical methods. Typical for gemini surfactants, imidazolium salts aggregate in water to form submicron 200 nm (in the case of di-butyl salt) or compact 6 nm (in the case of di-tetradecyl salt) particles. The catalytic activity of the complexes and systems in situ with Pd(OAc)2 in the hydrogenation reaction of nitroaromatics has been studied. The complex with butyl substituents was found to be superior to known catalytic systems in the reduction of p-nitrophenol (kapp = 1.53 min-1). According to microscopy data, after reduction palladium nanoparticles remained uniformly distributed in the butyl complex, while a lipophilic shell in the tetradecyl complex prevented the access of water-soluble regents to Pd centers. However, the lipophilic tetradecyl complex is more active in the reduction of water-insoluble p-ethylnitrobenzene and in cross-coupling reactions using water-insoluble lipophilic aryl halides due to the combination of micellar and metal complex catalysis. Our results provide insight into amphiphilic NHC palladium complexes as promising catalytic systems for aqueous media.

Palladium-Catalyzed Ortho-Alkylation of Iodoarenes Enabled by a Cooperative Cycloolefin Ligand and a Bulky Trialkylphosphine

We recently achieved ortho-alkylation of iodoarenes utilizing a dual-ligand catalytic system that effectively combines palladium/olefin ligand cooperative catalysis with reversible C(sp²)−I reductive elimination enabled by a bulky trialkylphosphine ligand. Through careful mechanistic investigations, we confirmed the compatibility of the crucial steps involved in this process by isolating key organometallic intermediates and studying their stoichiometry transformations. Utilizing this protocol, we successfully achieved the ortho-alkylation of a variety of iodoarene substrates, thereby expanding the scope of applications for Catellani-type reactions. This study showcases the synthetic potential of the Pd/olefin ligand cooperative system as an innovative complement to established Pd/NBE catalysis. In this Synpacts article, we present the conceptual framework underpinning this reaction and detail the key aspects of its development. 1Introduction 2Research Background 2.1The Catellani Reaction: Pd/Norbornene Catalysis 2.2Cooperative Cycloolefin Ligands for the Catellani-Type Reactions 2.3C-X Reductive Elimination on Pd Center 3Development of the Reaction 3.1Proof-of-Concept by Stoichiometric Reactions 3.2Substrate Scope and Synthetic Applications 4Conclusion

Redox Active vs Redox Neutral in Ru/Pd-Catalyzed Sulfonylation: Theoretical Insights into Structure-Activity Relationship between Metal Centers and Regio-Selectivity.

The structure-activity relationship between the metal center and regio-selectivity is persistently a pivotal scientific issue. To address this, we select the 2-phenylpyridine sulfonylation reactions catalyzed by ruthenium and palladium as research subjects. An extensive theoretical study has been conducted on their reaction mechanisms, the sources of regio-selectivity, and the evolution of electronic structures. The distinct electronic structures lead to completely different catalytic mechanisms and electronic structure evolution processes for ruthenium and palladium. Ruthenium tends to form six-coordinate octahedral complexes, thus undergoing an inner-sphere redox active Ru(II)-Ru(III)-Ru(IV)-Ru(II) catalytic cycle. In contrast, palladium tends to form four-coordinate planar quadrilateral complexes, hence undergoing an outer-sphere redox neutral Pd(II) catalytic cycle. The distinct electronic structure evolution processes fundamentally differentiate the radical attack modes in the sulfonation process, thereby determining the regio-selectivity of the reaction. In the Ru-catalyzed system, the meta-selectivity arises mainly from a more stable Schrock carbene-type meta-intermediate. For the Pd-catalyzed system, the ortho-selectivity mainly comes from the stabilizing effect of the Pd(II) center on the single electron. This study provides novel insights into how the electronic structure of metal centers influences the reaction mechanism and selectivity, making a theoretical contribution to a deeper comprehension of the mechanism and regio-selectivity underlying aromatic functionalization reactions.

Synthesis of Bis(diimino)palladium Nanosheets as Highly Active Electrocatalysts for Hydrogen Evolution.

Development of efficient electrocatalysts for hydrogen evolution reactions (HERs) is necessary to achieve environmentally friendly and sustainable hydrogen production. To reduce cost and to circumvent the scarcity of platinum, the most efficient catalyst for HER, it is essential to develop catalysts using ubiquitous base metals or minimal amounts of precious metals. Bis(diimino)metal (MDI) coordination nanosheets are potential HER catalysts because their electric conductivities, two-dimensionality, and porous structures provide large surface areas and efficient mass and electron transfer. In addition, with sparse metal arrangements in their chemical structures, nanosheets can reduce the amount of metal needed. We synthesized bis(diimino)palladium coordination nanosheets (PdDI) as a coordination polymer composed of bis(diimino)palladium, with semiconducting characteristics, using gas-liquid interfacial synthesis and electrochemical oxidation. These electrochemically synthesized PdDIs exhibit remarkable catalytic performance with overpotential reaching 10 mA cm-2 of 34 mV, a Tafel slope of 47 mV dec-1, and an exchange current density of 2.1 mA cm-2 after appropriate activation. This performance is closely comparable to that of metallic platinum. An ex-situ investigation of the activation process revealed that reduction of the divalent Pd center in bis(diimino)palladium produced a composite of Pd(0) species and PdDI, combining high catalytic activity with smooth electron transfer.

First report on the investigation of the pH dependent behavior in the complexes of palladium(II) acetylacetonate with isomers of dinitrobenzoate: Combined single crystal X-ray diffraction and Hirshfeld surface calculations

The novel six palladium acetylacetonate [Pd(acac)2] and isomers of dinitrobenzoate anions (e.g., 3,5-dinitrobenzoate (L1) and 2,4-dinitrobenzoate (L2)) based complexes (1–6) have been synthesized via a facile hydrothermal route. These complexes are further characterized by single crystal X-ray diffraction (SCXRD), IR spectroscopy, NMR spectroscopy, powder X-ray diffraction (PXRD), UV–vis spectroscopy, and thermogravimetric analysis (TGA). For the synthesis of these complexes, the initial precursors of isomers of dinitrobenzoates, i.e., 3,5 dinitrobenzoic acid (L1H) and 2,4 dinitrobenzoic acid (L2H) have been used at different pH conditions. The study evaluates the ability of the acetylacetonate group to act as a hydrogen bond acceptor in the presence of isomeric dinitrobenzoate ligands. The basic structure of Pd(acac)2 undergoes changes due to the varying chemical environment at different pH conditions. At lower pH levels, protonation of the acac group has occurred (e.g., complex 1), leading to changes in the coordination environment around the Pd(II) center. At the slightly basic pH value (⁓10), one of the acac anion is replaced with two ammonia molecules (e.g., complex 2, 4, and 5). Further increasing pH to 14, results in the replacement of both acac anions with four ammonia molecules (e.g., complex 3 and 6). The complexes 4 and 5 are pseudopolymorphs or solvates that are recovered from the same reaction mixture showing different morphology. These results are confirmed by NMR spectroscopy and single crystal X-ray diffraction. The crystallographic results have been amply supplemented by Hirshfeld surface analysis and other spectroscopic studies. The structural changes in complexes can impact the electronic properties and behavior of Pd(acac)2 in different chemical reactions. Therefore, it is important to consider the pH conditions when studying the structure and reactivity of Pd(acac)2 in various applications.

Synergistic Pd(OAc)2/CuI-catalyzed alkynylation of β-lactam derivative via Sonogashira coupling

Herein, a novel approach of bimetallic Pd(OAc)2/CuI-catalyzed alkynylation of 3-chloroazetidin-2-one (β-lactam derivative) with terminal alkyne via tandem C–C bond activation/Sonogashira-type cross-coupling reaction is developed. This synthesis encompasses a sequence of inert Csp3–X/Csp–H functionalization processes involving the coupling of the C(sp3) adjacent to the 3-chloroazetidin-2-one with the C(sp) of a terminal alkyne. The final analogs are synthesized by means of the indole-benzothiazole Schiff base formation, cyclization of the Schiff base to generate the β-lactam derivative, and Sonogashira coupling to afford a C(sp3)–C(sp) bond. In addition, indole, benzothiazole, and azetidine-2-one have been identified to be highly efficient heterocyclic scaffolds with a range of pharmacological benefits. It encouraged us to discover a hybrid compound that had each of these moieties. Cooperation between two different metals is essential for the successful implementation of this approach. Specifically, the interaction between the Pd and Cu centers in the transmetallation step is depicted through a plausible mechanistic route. The reaction conditions have been optimized by varying catalyst and ligand loadings, bases, temperatures, and solvents. The reaction is highly efficient, yielding alkynylated products in up to 84 % yield with a wide range of substrates and functional group tolerance, thereby serving as a functional model for the Sonogashira coupling reaction.

Synthesis and characterizations of a novel trans-Pd(O,N)2 complex with an AZO-dye ligand: Crystal structure, theoretical studies and DNA binding interactions

The transition metal-azo dye complexes have attracted attention in both fundamental and applied research due to their electronic and structural properties, particularly due to their potential to yield new compounds with diverse biological activities and anticancer agents. A novel square planar-trans-Pd(O,N)2 was synthesized with a high yield utilizing a one-pot approach employing (E)-methyl 2-((2-hydroxynaphthalen-1-yl)diazenyl)benzoate as the AZO-dye ligand. In order to analyze their structure and understand their properties. The desired complex was characterized using FT-IR, UV–Vis, NMR, and CHN-EA techniques. Subsequently, theoretical modeling of the complex was performed using MEP/MAC/NPA methodologies. Two methodologies were employed to monitor the coordination process of AZO-ligand with Pd(II): UV–Vis absorption and FT-IR spectrum analysis. The TD-DFT and DFT/IR behaviors were simultaneously assessed to compare the experimental results with theoretical predictions. Furthermore, both SC-XRD and DFT analysis demonstrated that the deprotonated phenolic diazene form of the AZO-ligand attached to the Pd(II) center by utilizing one nitrogen atom of the AZO-ligand and the ionic oxygen of the phenol. The SC-XRD analysis verified the presence of a slightly distorted square-planar geometry around the PdII center in the neutral trans-Pd(O,N)2 complex. All of the oxygen atoms in the complex participated in non-classical C-H….O hydrogen bonding, leading to the formation of novel edge-fused rings R22(24) and R22(12) synthons. These synthons create a 3D-network with a linked parallel matrix. Interestingly, Hirshfeld surface analysis (HSA) stimulation revealed many hot sites on the complex surface, confirming the formation of strong non-classical [C-H....O] interactions. From the observed docking behavior with the DNA, it can be concluded that the trans-Pd(O,N)2 showed superior binding compared to the free AZO-ligand. The results of this work are a contribution to the study of this class of metal complexes and their physicochemical properties and offer promising perspectives for the realization of new works.

The catalytic enhancement of the hydrogen evolution reaction facilitated by Pd coating on SrTiO3

The wide bandgap structure of 3.2 eV has made SrTiO3 (STO) well-known for its exclusive responsiveness to ultraviolet (UV) light. By anchoring Pd to the surface oxygen atoms of STO, we have successfully reduced the forbidden bandwidth of STO to 2.75 V, thereby extending its light absorption range to visible light. Simultaneously, trace amounts of low-valent Pd were distributed on the surface, significantly enhancing the photocatalytic hydrogen precipitation rate to 7366.07 μmol·g-1·h-1. This innovative approach led to the development of a novel nanocatalyst with numerous tailored active sites specifically designed for efficient photocatalytic hydrogen evolution. X-ray fine spectroscopy confirms Pd was successfully anchored to the STO surface and coordinated with surface O and the occurrence of Pd and Pd coordination at 2.0 Å from the Pd center in the R-space. Density functional theory (DFT) calculations further validate that anchoring Pd onto the STO surface reduces the free energy of adsorption for H* on these active sites. This discovery presents a promising strategy for immobilizing metal catalysts at perovskite STO’s unit sites.

Understanding and Controlling Reactivity Patterns of Pd1@C3N4-Catalyzed Suzuki-Miyaura Couplings.

Using heterogeneous single-atom catalysts (SACs) in the Suzuki-Miyaura coupling (SMC) has promising economic and environmental benefits over traditionally applied palladium complexes. However, limited mechanistic understanding hinders progress in their design and implementation. Our study provides critical insights into the working principles of Pd1@C3N4, a promising SAC for the SMC. We demonstrate that the base, ligand, and solvent play pivotal roles in facilitating interface formation with reaction media, activating Pd centers, and modulating competing reaction pathways. Controlling the previously overlooked interplay between base strength, reagent solubility, and surface wetting is essential for mitigating mass transfer limitations in the triphasic reaction system and promoting catalyst reusability. Optimum conditions for Pd1@C3N4 require polar solvents, intermediate base strength, and increased water content. Our investigations reveal that high selectivity requires minimizing competitive coordination of bases and phosphine ligands to the Pd centers, to avoid homocoupling and alternative reductive elimination mechanisms giving rise to phosphonium side-products. Furthermore, in situ XAS investigations probing electronic structures and coordination environments of Pd sites further rationalize the base and ligand coordination, confirming and expanding upon previous computational hypotheses for Pd1@C3N4. This understanding allows for designing a more selective ligand-free reaction pathway using the solvent and base to modulate the chemical environment of the active sites. We highlight the importance of environment-compatible surface tension, the creation of coordinatively available active sites, and the stabilization of partially reduced Pd centers, emphasizing the importance of mechanistic studies to advance the design of SACs in organic liquid phase reactions.

A Prospective Cohort Study Evaluating Impact of Sarcopenia on Hospitalization in Patients on Continuous Ambulatory Peritoneal Dialysis

Data regarding the association of sarcopenia with hospitalization has led to inconclusive results in patients undergoing dialysis. The main goal of this research was to investigate the association between sarcopenia and hospitalization in Chinese individuals on continuous ambulatory peritoneal dialysis (CAPD). Eligible patients on CAPD were prospectively included, and followed up for 48 weeks in our PD center. Sarcopenia was identified utilizing the criteria set by the Asian Working Group on Sarcopenia in 2019 (AWGS 2019). Participants were categorized into sarcopenia (non-severe sarcopenia + severe sarcopenia) and non-sarcopenia groups. The primary outcome was all-cause hospitalization during the 48-week follow-up period. Association of sarcopenia with all-cause hospitalization was examined by employing multivariate logistic regression models. The risk of cumulative incidence of hospitalization in the 48-week follow-up was estimated using relative risk (RR and 95% CI). The cumulative hospitalization time and frequency at the end of 48-week follow-up were described as categorical variables, and compared by χ2 test or fisher's exact test as appropriate. Subgroup and sensitivity analyses were also conducted to examine whether the potential association between sarcopenia and hospitalization was modified. A total of 220 patients on CAPD (5 of whom were lost in follow-up) were included. Prevalences of total sarcopenia and severe sarcopenia were 54.1% (119/220) and 28.2% (62/220) according to AWGS 2019, respectively. A total of 113 (51.4%) participants were hospitalized during the 48-week follow-up period, of which, the sarcopenia group was 65.5% (78/119) and the non-sarcopenia group was 34.7% (35/101), with an estimated RR of 1.90 (95%CI 1.43–2.52). The cumulative hospitalization time and frequency between sarcopenia and non-sarcopenia groups were significantly different (both P < 0.001). Participants with sarcopenia (OR = 3.21, 95%CI 1.75–5.87, P < 0.001), non-severe sarcopenia (OR = 2.84, 95%CI 1.39–5.82, P = 0.004), and severe sarcopenia (OR = 3.66, 95%CI 1.68–8.00, P = 0.001) demonstrated a significant association with all-cause hospitalization compared to individuals in non-sarcopenia group in the 48-week follow-up. Moreover, participants in subgroups (male or female; < 60 or ≥ 60 years) diagnosed with sarcopenia, as per AWGS 2019, were at considerably high risk for hospitalization compared to those with non-sarcopenia. In sensitivity analyses, excluding participants lost in the follow-up, the relationships between sarcopenia and hospitalization (sarcopenia vs. non-sarcopenia; severe sarcopenia/non-severe sarcopenia vs. non-sarcopenia) were consistent. This research involving Chinese patients on CAPD demonstrated a significant association between sarcopenia and incident hospitalization, thereby emphasizing the importance of monitoring sarcopenia health in this population.

Topological defects induced by N incorporation-evaporation strategy promote the metal-support interaction over Pd/NC for catalytic formic acid dehydrogenation

Hydrogen (H2) production from formic acid (FA) decomposition is considered to be the application pattern of clean energy with board prospects. However, in precious metal-based catalysts, the weak metal-support interaction always leads to the reduction of exposure and utilization of active centers. Herein, N incorporation-evaporation strategy was employed to generate more topological carbon defects to deposit Pd nanoparticles (Pd NPs). The results demonstrate that topological defects are able to promote the electron transfer at the Pd-carbon interface, resulting in enhanced metal-support interaction. The Pd/NC800 catalyst with numerous topological defects exhibits significant activity (turnover frequency of 1251 h−1) and stability under mild conditions because of highly dispersed Pd centers with a modulated electronic state. The mechanism of enhancing metal-support interaction through topological defects was discussed through theoretical calculations, and it was found that the optimal topological configuration is the 5–8-5 defect induced by pyrrolic N. This work casts a new light on understanding the interaction between carbon configurations and active metals.

Constructing Pd and Cu Crowding Single Atoms by Protein Confinement to Promote Sonogashira Reaction.

For multicenter-catalyzed reactions, it is important to accurately construct heterogeneous catalysts containing multiple active centers with high activity and low cost, whichis more challenging compared to homogeneous catalysts because of the low activity and spatial confinement of active centers in the loaded state. Herein, a convenient protein confinement strategy is reported to locate Pd and Cu single atoms in crowding state on carbon coated alumina for promoting Sonogashira reaction, the most powerful method for constructing the acetylenic moiety in molecules. The single-atomic Pd and Cu centers take advantage in not only the maximized atomic utilization for low cost, but also the much-enhanced performance by facilitating the activation of aryl halides and alkynes. Their locally crowded dispersion brings them closer to each other, which facilitates the transmetallation process of acetylide intermediates between them. Thus, the Sonogashira reaction is drove smoothly by the obtained catalyst with a turnover frequency value of 313 h-1, much more efficiently than that by commercial Pd/C and CuI catalyst, conventional Pd and Cu nanocatalysts, and mixed Pd and Cu single-atom catalyst. The obtained catalyst also exhibits the outstanding durability in the recycling test.

Will We Witness Enzymatic or Pd-(Oligo)Peptide Catalysis in Suzuki Cross-Coupling Reactions?

Despite the development of numerous advanced ligands for Pd-catalyzed Suzuki cross-coupling reaction, the potential of (oligo)peptides serving as ligands remains unexplored. This study demonstrates via density functional theory (DFT) modeling that (oligo)peptide ligands can drive superior activity compared to classic phosphines in these reactions. The utilization of natural amino acids such as Met, SeMet, and His leads to strong binding of the Pd center, thereby ensuring substantial stability of the system. The increasing sustainability and economic viability of (oligo)peptide synthesis open new prospects for applying Pd-(oligo)peptide systems as greener catalysts. The feasibility of de novo engineering an artificial Pd-based enzyme for Suzuki cross-coupling is discussed, laying the groundwork for future innovations in catalytic systems.

Synthesis of a Family of Pd(II) Complexes Using Pyridyl-Ketone Ligands: Crystal Structure, Thermal, Physicochemical, XRD/HSA, Docking, and Heck Reaction Application.

Four Pd(II) complexes, (dpk)PdCl2 (complex-1), and (dpk)Pd(OAc)2 (complex-2) have been prepared using di(2-pyridyl) ketone as the chelate ligand (dpk). The (dpk·EtOH)PdCl2 (complex-3) and (dpk·EtOH)Pd(OAc)2 (complex-4) were synthesized by selectively introducing complex-1 and complex-2 to an EtOH in situ nucleophilic addition reaction on the O=C of the dpk ligand, respectively. All complexes were characterized using CHN-EA, UV-vis, FT-IR, FAB-MS, EDX, TGA, and NMR physicochemical tools. The XRD-crystallography technique was employed to ascertain the structure of complex-3. The analysis revealed a monoclinic/P21/c crystal system characterized by a square planar structure oriented in the cis direction around the Pd center. Several C-H···Cl and O-H···O H-bonds constructing 2D-S12 and S7 synthons were confirmed via XRD/HSA interactions. The influence of EtOH addition to the O=C group of dpk in (dpk)PdCl2 was documented by using UV-vis/FT-IR spectra and TGA analysis. As catalysts, all complexes have demonstrated a notable catalytic function in the Heck reaction, resulting in a high yield under gentle conditions using iodobenzene and methyl acrylate as model reactions. Moreover, the complex-1 and complex-3 docking activity was evaluated against 1BNA-DNA.

Vibrational microspectroscopy as a tool to unveil new chemotherapeutic strategies against osteosarcoma

Over the years, osteosarcoma therapy has had a significative improvement with the use of a multidrug regime strategy, increasing the survival rates from less than 20 % to circa 70 %. Different types of development of new antineoplastic agents are critical to achieve irreversible damage to cancer cells, while preserving the integrity of their healthy counterparts. In the present study, complexes with two and three Pd(II) centres linked by the biogenic polyamines: spermine (Pd2SpmCl4) and spermidine (Pd3Spd2Cl6) were tested against non-malignant (osteoblasts, HOb) and cancer (osteosarcoma, MG-63) human cell lines. Either alone or in combination according to the EURAMOS-1 protocol, they were used versus cisplatin as a drug reference. By evaluating the cytotoxic effects of both therapeutic approaches (single and drug combination) in HOb and MG–63 cell lines, the selective anti-tumoral potential is assessed. To understand the different treatments at a molecular level, Synchrotron Radiation Fourier Transform Infrared and Raman microspectroscopies were applied. Principal component analysis and hierarchical cluster analysis are applied to the vibrational data, revealing the major metabolic changes caused by each drug, which were found to rely on DNA, lipids, and proteins, acting as biomarkers of drug-to-cell impact. The main changes were observed for the B-DNA native conformation to either Z-DNA (higher in the presence of polynuclear complexes) or A-DNA (preferably after cisplatin exposure). Additionally, a higher effect upon variation in proteins content was detected in drug combination when compared to single drug administration proving the efficacy of the EURAMOS-1 protocol with the new drugs tested.

Droplet‐Based Microfluidics Reveals Insights into Cross‐Coupling Mechanisms over Single‐Atom Heterogeneous Catalysts

AbstractSingle‐atom heterogeneous catalysts (SACs) hold promise as sustainable alternatives to metal complexes in organic transformations. However, their working structure and dynamics remain poorly understood, hindering advances in their design. Exploiting the unique features of droplet‐based microfluidics, we present the first in‐situ assessment of a palladium SAC based on exfoliated carbon nitride in Suzuki–Miyaura cross‐coupling using X‐ray absorption spectroscopy. Our results confirm a surface‐catalyzed mechanism, revealing the distinct electronic structure of active Pd centers compared to homogeneous systems, and providing insights into the stabilizing role of ligands and bases. This study establishes a valuable framework for advancing mechanistic understanding of organic syntheses catalyzed by SACs.

Droplet-Based Microfluidics Reveals Insights into Cross-Coupling Mechanisms over Single-Atom Heterogeneous Catalysts.

Single-atom heterogeneous catalysts (SACs) hold promise as sustainable alternatives to metal complexes in organic transformations. However, their working structure and dynamics remain poorly understood, hindering advances in their design. Exploiting the unique features of droplet-based microfluidics, we present the first in-situ assessment of a palladium SAC based on exfoliated carbon nitride in Suzuki-Miyaura cross-coupling using X-ray absorption spectroscopy. Our results confirm a surface-catalyzed mechanism, revealing the distinct electronic structure of active Pd centers compared to homogeneous systems, and providing insights into the stabilizing role of ligands and bases. This study establishes a valuable framework for advancing mechanistic understanding of organic syntheses catalyzed by SACs.