Iron-NHC (N-heterocyclic carbene) complexes hold strong promise as earth-abundant alternatives to Ru- and Ir-based photosensitizers, but their synthesis represents additional challenges. Here, we present a systematic study aimed at developing a robust, reproducible, and scalable protocol for the synthesis of [Fe(Brphtmeimb)2]+ that is suitable for researchers of all skill levels. By examining the effects of base, solvent, temperature, concentration, and iron source, we identified several previously overlooked parameters, including FeBr2 solubility, temperature-dependent precipitation, and solvent quality, that significantly impact reaction outcome. Optimization revealed that low-temperature addition of LiHMDS and dilute reaction conditions (0.02 M) afford consistently improved yields. Further adjustment of ligand and base stoichiometry enabled reliable scale-up, delivering the target complex in 64% yield on a 1 mmol scale. This practical procedure provides broad, dependable access to [Fe(Brphtmeimb)2]+, facilitating its use across catalysis, materials chemistry, and related fields. Furthermore, we show postfunctionalization routes of [Fe(Brphtmeimb)2]+ via Suzuki-type coupling and expand the reaction scope to include additional transition metals such as Mn(IV) and Co(III).

New series of triazole/pyrazole and tetrazole/triazole/pyrazole ligands were synthesized and coordinated with various transition metals to yield a diverse library of 14 complexes. All compounds were fully characterized by elemental analysis, mass spectrometry, powder X-ray diffractometry, and a range of spectroscopic techniques (1H NMR, 13C NMR, FT-IR, and UV-visible diffuse reflectance). The crystal and molecular structures were elucidated via single-crystal X-ray diffraction, and their supramolecular features were explored through Hirshfeld surface analysis. The 57Fe Mössbauer and magnetic SQUID measurements confirmed the high-spin nature of the FeII complex 1. In the three human cancer cell lines, most metal complexes are somewhat more cytotoxic than the inactive ligands, with Co(II) complexes 2 and 8 being the most potent in two of the cell lines (with IC50 values in the two-digit micromolar range). Overall, this study highlights how blending tetrazole/triazole/pyrazole ligands with transition metals can lead to coordination compounds with potential in anticancer research, as a proof of concept. These results add valuable insight to the expanding field of metal-based therapeutics and could help guide the development of next-generation, more effective agents.

We show that solvent selection plays a decisive role in chiral resolution of RS-phenprocoumon-quinidine. In particular, formation of a bis-acetone solvate suppresses solid solution formation, and affords spontaneous enantioselective crystallization of S-phenprocoumon with enantiomeric excesses of up to 92% in a single resolution step.

AIE material (DHNB) detects toxic hair-dye ingredients, p -phenylenediamine (PPD) and Bandrowski's base (BWB) in contrasting fluorescence modes. DHNB identifies PPD in commercial formulations and displays distinct current–voltage characteristics.

In this work, we report the synthesis of two new Co(ii) metal salts [Co(H2O)6](Hpsca)2 & centerdot;nH2O (n = 2, 4) incorporating a p-sulfocinnamic acid counter anion (Hpsca-). Together with the previously reported iron(ii) analogue [Fe(H2O)6](Hpsca)2 & centerdot;2H2O, these precursors were utilized to synthesize four new coordination complexes [M(bipy)3](Hpsca)2 & centerdot;2MeOH (M = Fe (1), Co (2), bipy = 2,2 '-bipyridine), [Fe(1-bpp)(Hpsca)(H2O)(MeOH)]Hpsca & centerdot;MeOH (3, 1-bpp = 2,6-di(1-pyrazolyl)pyridine) and [Fe(3,2,3-sal2tet)]Hpsca & centerdot;H2O (4), 3,2,3-sal2tet = 2,2 '-((1Z,13Z)-2,6,9,13-tetraazatetradeca-1,13-diene-1,14-diyl) diphenol. Single crystal X-ray diffraction analyses revealed that all complexes consist of discrete mononuclear cationic units, while the Hpsca- anion forms different supramolecular arrangements. 57Fe M & ouml;ssbauer spectroscopy confirms the low-spin state for Fe(ii) ions in 1 and Fe(iii) ions in 4, in accordance with crystallographic results. This work highlights the versatility of the Hpsca- counteranion to stabilize diverse crystal architectures as well as its ability to couple solid-state reactivity and spin state modulation, thanks to the potential anion-driven light induced spin change based on the solid state [2 + 2] photodimerization of Hpsca-.

The electrochemical reduction of CO2 (CO2RR) into value-added chemicals offers a promising route toward a circular carbon economy and a reduced reliance on fossil fuels. A detailed understanding of the structural and electronic factors that govern the performance of molecular CO2RR electrocatalysts is essential for designing efficient and tunable systems. Here, we report a series of rhenium(I) complexes, fac-[Re-I(6,6 '-(R)(2)-bpy)(CO)(3)Cl] (bpy = 2,2 '-bipyridine; R = mesityl (mes), 2,4,6-triisopropylphenyl (trip), or isophthalic acid (phth)) and evaluate their electrocatalytic activity. Among these, fac-[Re-I(6,6 '-(mes)(2)-bpy)(CO)(3)Cl] exhibited the highest performance, enabling selective CO2-to-CO conversion for 1 h with Faradaic efficiency (FE) >97%, representing an enhanced activity level for Rebpy catalysts. Single-crystal X-ray diffraction and density functional theory (DFT) calculations indicated that favorable CO2 binding can be promoted by tilting the 6,6 '-(mes)(2)-bpy ligand (from the Re-CO coordination plane), providing mechanistic insight into the observed enhancement. The study consequently demonstrates a rational correlation between the CO2 electrocatalytic performance of Rebpy catalysts and their structural variations, as derived from X-ray data and corroborated by computational modeling.

A bidentate ligand 1‐methyl‐3‐(5‐methyl‐1H‐pyrazol‐3‐yl)‐1H‐1,2,4‐triazole ( L21 ), and transition‐metal complexes, [Cu(L21) 2 (NO 3 ) 2 ] ( 1 ) and [Cr 2 (L21) 4 (OH) 2 ](NO 3 ) 4 ( 2 ), were synthesized and characterized by single‐crystal X‐ray diffraction, FT‐IR, UV–vis spectroscopy, and high‐resolution mass spectrometry. Complex 1 contains a Cu II center located on an inversion center with chelating L21 ligands in the equatorial plane and coordinated nitrate anions, while 2 is a dinuclear Cr III complex with a Cr···Cr separation of 2.998 Å, stabilized by bridging hydroxide ligands and counterbalanced by lattice nitrate anions. While L21 showed negligible antibacterial activity, its coordination with metal centers led to a marked improvement. In assays against E. coli , P. aeruginosa , S. aureus , and B. subtilis , 2 exhibited inhibition zones ranging from 9.75 ± 0.92 to 10.25 ± 0.31 mm and a minimum inhibitory concentration of 2.5 mmol/L. Frontier orbital analysis revealed a higher electrophilicity index for 2 ( ω = 50.19/48.95 eV) compared with 1 ( ω = 2.92/7.26 eV), indicating a greater tendency to accept electron density, while Hirshfeld and noncovalent interaction analyses revealed a denser interaction network in 2 . Molecular docking against aquaporins, S. aureus phosphofructokinase, and human serum albumin revealed stronger predicted binding affinities for 2 . L21 is a tunable scaffold for developing biologically active transition‐metal complexes with antibacterial properties.

Metal dodecaborates, particularly lithium dodecaborate (Li2B12H12), are promising ionic conductors, but their broader application is hindered by complex synthesis. Here, we report a facile solvothermal synthesis of Li2B12H12 via the reaction of lithium borohydride (LiBH4) with borane dimethyl sulfide complex (DMS·BH3) in glyme solvents. This synthesis can be conveniently performed either in a Schlenk flask (with or without reflux) or in an autoclave, demonstrating high yields (up to 96%) and excellent purity. The enclosed system provided by the autoclave was shown to be more favorable for the synthesis of the B12H122- anion. A detailed mechanistic investigation utilizing 11B nuclear magnetic resonance (11B NMR) spectroscopy revealed the stepwise formation of B2H7-, B3H8-, B9H14-, B11H14-, and B11H132- intermediates. This synthetic strategy was successfully extended to other alkali metal dodecaborates (Na, K), and their glyme-coordinated complexes were characterized by single-crystal X-ray diffraction. Furthermore, we introduce a solvent-exchange approach using weakly coordinating solvents such as dimethyl sulfoxide (DMSO) or water, enabling simple and efficient desolvation, thereby offering a practical new approach to obtain anhydrous metal dodecaborates.

The use of iron-based photosensitizers in light-mediated electron transfer chemistry remains limited by their inherently short excited-state lifetimes. Here, we report the design, synthesis, and photophysical characterization of a novel iron(III) photosensitizer, [Fe(LPhBMes)2]+, in which the tridentate NHC ligand framework incorporates a Lewis acidic dimesityl boron moiety. Steady-state and time-resolved spectroscopy reveal that [Fe(LPhBMes)2]+ exhibits photophysical properties nearly identical to the widely studied [Fe(LPh)2]+, yet demonstrates strikingly different reactivity upon binding small, strongly Lewis basic anions such as fluoride or hydroxide. Anion binding induces boronate formation, which subsequently triggers fast intramolecular electron transfer, leading to a reactive charge-separated species formed via irreversible bond cleavage. In-depth photostability measurements shed light on anion-concentration dependent degradation pathways. These findings represent the first integration of Lewis acidic triarylborane substituents into an iron(III)-based photosensitizer, establishing a platform for tuning excited-state dynamics together with exploiting static quenching strategies to bypass diffusion-limited electron transfer. This approach to selectively trigger excited-state charge separation and externally stimulated bond cleavage represents a promising avenue in targeted phototherapeutics application and drug release. Both strategies are potentially interesting to make iron-based photosensitizers more accessible for light-driven applications in the future.

Mixed ionic-electronic conductors (MIECs) are highly sought after for electrochemical systems because they support concurrent charge and mass transport. Yet, structurally well-defined single-phase MIECs remain scarce, as most systems rely on physical mixtures of ionic and electronic conductors. Here, we introduce a cation-rich design strategy to realize solid-state mixed Li+-electronic conduction in a two-dimensional copper-catecholate metal-organic framework, Cu3(HOTAT)2, built from the 3-fold symmetric new ligand 2,3,7,8,12,13-hexahydroxytriazatruxene (HHTAT). Owing to the combined redox activity of Cu2+/Cu+ and the HOTAT ligand, controlled fractional reduction generates a family of LixCu3(HOTAT)2 (0 ≤ x ≤ 7.50) phases with tunable transport properties, in good agreement with electronic-structure calculations. The Li-rich phase Li7.50Cu3(HOTAT)2 exhibits intrinsic mixed conduction at room temperature, with an electronic conductivity of 2.8 × 10-3 S cm-1, and solid-state Li+ conductivity of 1.1 × 10-3 S cm-1. As a proof of concept, Li7.50Cu3(HOTAT)2 operates as a homogeneous cathode in all-solid-state Li batteries, delivering 100 mAh g-1 after 100 cycles with ∼99.8% Coulombic efficiency, indicative of highly reversible electrochemical behavior. These results establish cation-rich reduction of redox-active 2D MOFs as an efficient route to engineer solid-state mixed Li+-electronic conductors, opening a pathway toward dual-conducting porous materials for solid-state electrochemical technologies.

The modulation of physicochemical properties through the discovery of new solid forms has attracted significant interest in the pharmaceutical industry. Herein, a novel cocrystal of lenalidomide with quercetin was designed upon crystal engineering principles. Bearing in mind the importance of developing sustainable methods for the pharmaceutical industry, the synthesis of the novel cocrystals was explored by different mechanochemical approaches and slurry techniques for comparison purposes. Thus, the cocrystal was produced by liquid-assisted grinding in ball milling, liquid-assisted resonant acoustic mixing, and the slurry method. All the methods yielded the same final form with similar properties. From the point of view of properties enhancement, solubility studies showed that the cocrystal exhibited lower solubility than that of pure lenalidomide under simulated conditions of gastric and intestinal fluids, suggesting that the cocrystal may function as an extended-release form of lenalidomide. Furthermore, this cocrystal remained stable under accelerated stability conditions, indicating that atmospheric relative humidity does not represent a risk for the handling or storage of these compounds in the solid state.

Integrating photoactive anions into spin crossover systems offers a promising route toward light-controlled modulation of spin states, enhancing the utility of these materials in photospin information storage. In this study, we report the synthesis and characterization of a novel Fe(II) salt, [Fe(H2O)6](2-As)2, incorporating anthracene-2-sulfonate (2-As-) as the counteranion, which holds the potential to undergo solid-state photodimerization under favorable packing conditions. Utilizing this salt as a precursor, three mononuclear Fe(II) complexes were successfully synthesized: [Fe(2-pic)2(2-As)2] (1, 2-pic = pyridin-2-ylmethanamine), [Fe(2,6-hdp)2](2-As)2 (2, 2,6-hdp = 2,6-bis((E)-1-hydrazineylideneethyl) pyridine), and [Fe(3-bpp)2](2-As)2 & centerdot;2MeOH & centerdot;H2O (3, 3-bpp = 2,6-di(pyrazol-3-yl) pyridine). Magnetic susceptibility measurements and 57Fe Mossbauer spectroscopy reveal that complexes 1 and 2 remain in high-spin and low-spin states, respectively, over the 4-400 K range. Complex 3 exhibits a low-spin state in the solvated form but undergoes a gradual and incomplete spin crossover behavior with a small thermal hysteresis centered at similar to 290 K upon desolvation. Single-crystal X-ray diffraction indicates that the 2-As- anion adopts a face-to-edge stacking mode rather than the face-to-face arrangement required for solid-state photoreactivity. However, the extensive hydrogen bonding observed around the sulfonate groups suggests a viable crystal-engineering strategy to modulate anthracene stacking and enable future photoinduced spin-state switching.

Diasteriomeric ionic cocrystallization is introduced as a novel crystallization-based resolution tool. RS-Ibuprofen sodium is succesfully resolved using proline as a resolution agent, achieving ee > 90% in a single resolution step. This work, for the first time, demonstrates diastereomeric ionic cocrystallization as a powerful approach to chiral resolution.

We report a new sulfonamide-terephthalate linker, 2,5-di(methylsulfonamido)terephthalic acid (H4-DSATA), and its incorporation into a MIL-88B-type mixed-valence iron MOF, [(Fe2+Fe3+ 2)(μ3-O)(H2-DSATA)3•3DMF]. Despite mixed-valence Fe nodes and a redox-active ligand environment, the framework shows limited electronic transport, which DFT attributes to strong electronic-state localization near the Fe─O units.

Self-assembly of aromatic oligoamides into multihelical structures is a powerful strategy for developing complex and functional molecular architectures. As the hybridization process is directed by the folded state of the oligomers, inducing changes in the folding can be used to control the self-assembly. As one approach for this, Diels-Alder reactions on diazaanthracene monomers allow site-specific modification of aromatic oligoamides. The reaction leads to a bend in the monomer that, in turn, distorts the structure of the oligomer. Herein, we show that this strategy can be used to control the self-assembly of the oligomers. Using reversible Diels-Alder reactions allows switching between distinct folded states with different self-assembly preferences. This strategy can be applied during oligomer synthesis to prevent self-assembly or postsynthetically to disassemble multihelical structures. In complex systems containing multiple oligomers, we show that the modification can further be used to direct social versus narcissistic self-sorting, allowing for the switch between homomeric and heteromeric double helical assemblies.

While common in biological systems, building blocks with low symmetry and flexibility pose numerous problems for synthetic self-assembly such as the formation of isomers of assemblies that are usually difficult to distinguish and purify. We herein report a design and synthesis strategy relying on shape complementarity and conformational constraints in dual curvature ligands that effectively promotes high selectivity during self-assembly and self-sorting of metal-organic assemblies. Three aromatic amide-based ligands (L1-L3) with a central 1,8-diazatriptycene core were designed and used for self-assembly with Pd2+. While hundreds of stereoisomers based on the conformational flexibility around the amides and the unsymmetrical non-planar structure of the core are possible upon coordination with the metal, the constraints designed into the ligands direct the self-assembly towards only a single Pd2L4 cage (L1) or Pd4L8 double-walled metallomacrocycle (L2) structure, even in mixtures of the ligands. We further demonstrate that this structural approach and the modularity of the ligand synthesis affords ready access to the first deep endohedral functionalized double-walled Pd4L8 cavitands (L3). These results highlight the potential of this new design strategy and open the door to selectively functionalized cavity-based architectures for numerous applications.

Metal-organic frameworks (MOFs) with mixed proton and electron conductivity (MPEC) are promising materials for electrochemical energy systems, yet few examples merge these properties within a single phase. Here, we report a series of breathable 3D MOFs featuring mixed conduction with the general formula H12-M2-(DOBDP)3 (wherein M(Ill) = Fe, Al, SC, and In and H6-DOBDP = 2,5-dihydroxy-1,4-benzenediphosphonic acid). The metal-phosphonate nodes and uncoordinated phosphonate (P-OH) groups enable the structure dynamics as well as proton conductivity, assisted by water channels. High proton conductivity (1.6 x 10-4 S/cm) and moderate electron conductivity (8.3 x 10-7 S/cm) are measured for the hydrated state of the Fe-MOF phase, whereas the Al phase exhibits only proton conductivity, highlighting the critical role of the Fe center in enabling MPEC. These findings advance the understanding of dual-conductive MOFs and establish a framework for designing next-generation materials with combined ion and electron transport.

Facilitating rapid charge transfer in electrode materials necessitates the optimization of their ionic transport properties. Currently, only a limited number of Li/Na-ion organic cathode materials have been identified, and those exhibiting intrinsic solid-phase ionic conductivity are even rarer. In this study, we present tetra-lithium and sodium salts with the generic formulae: A4-Ph-CH3P and A4-Ph-PhP, wherein A = Li, Na; Ph-CH3P = 2,5-dioxido-1,4-phenylene bis(methylphosphinate); Ph-PhP = 2,5-dioxido-1,4-phenylene bis(phenylphosphinate), as novel alkali-ion reservoir cathode materials. Notably, A4-Ph-PhP exhibits impressive Li-ion and Na-ion conductivities, measured at 2.6 x 10-7 and 1.4 x 10-7 S cm-1, respectively, in a dry state at 30 degrees C. To the best of our knowledge, these represent the first example of small-molecule organic cathode materials with intrinsic Li+ and Na+ conductivity. Theoretical calculations provide further insight into the electrochemical activity of the Li/Na-phenolate groups, as well as the enhanced electron affinity resulting from -phenyl and -Na substitutions. Additionally, Na4-Ph-PhP displays two distinct charge-discharge plateaus at approximately 2.2 V and 2.7 V, and 2.0 V and 2.5 V vs. Na+/Na, respectively, and demonstrates stable cycling performance, with 100 cycles at a rate of 0.1C and an impressive 1000 cycles at 1C. This study not only expands the portfolio of phenolate-based organic salts for use in metal-ion batteries but also underscores the potential of phosphonate-based organic materials in advancing energy storage technologies.

The cocrystallization of two small, common organic molecules, namely dl-2-phenoxypropionic acid and dl-proline, resulted in the formation of a hydrogen-bonded organic framework with a large unit cell. The obtained solid displays a structure possessing unidimensional ultramicroporous channels, whose functionality was shown by dynamic water vapor sorption and reversible xenon sorption assessed by in situ X-ray powder diffraction.