This study presents the synthesis, structural architecture, density functional theory (DFT) investigations, third-order nonlinear optical (NLO) properties, and biological evaluations of two organic–inorganic hybrid compounds based on the dicationic 1-(4-pyridyl)piperazine ligand: (C9H15N3)2+.HgCl42- (Compound I) and (C9H15N3)2+.CuCl42- (Compound II) Single-crystal X-ray diffraction reveals that both hybrid compounds assemble into robust 3D supramolecular networks governed by extensive ionic charge-assisted (N–H···Cl, C–H···Cl) hydrogen bonds. Hirshfeld surface analysis demonstrates that H···Cl (up to 37.1) and H···H contacts dominate the crystal packing. Quantum theory of atoms in molecules (QTAIM), non-covalent interaction (NCI) calculations and Time-dependent DFT (TD-DFT) validate the purely non-covalent character of these lattice-stabilizing interactions. Single-beam Z-scan measurements under continuous-wave excitation show that both complexes exhibit strong reverse saturable absorption (RSA) and thermal self-defocusing behavior. Compound II demonstrates a significantly enhanced third-order susceptibility χ3 = 1.899 × 10–5 compared to Compound I χ3= 1.25 × 10–5 driven by efficient dication-to-halometalate electronic coupling and LMCT interactions. Furthermore, Compound I exhibited pronounced antibacterial efficacy against Escherichia coli 19 mm and S. aureus 21 mm while Compound II demonstrated superior cytotoxic potency against MDA-MB-231 triple-negative breast cancer cells with an IC50 of 10.96 μg/mL (compared to 25.25 μg/mL for Compound I). These results highlight the dual potential of compound I and II in photonic devices and as next-generation anti-cancer therapeutics.

The catalytic electrocyclization of heptatrienes represents an attractive strategy to access seven-membered carbocycles from acyclic precursors, whose medium-size cyclic saturated hydrocarbon counterparts display physicochemical properties of interest for jet-fuel applications. Here we uncover the potential of alkali-metal amides to enable an efficient, high-yielding and multigram-scale electrocyclization of biobased ocimene and related trienes derived from isoprene. Experimental results show that both the nature of alkali metal (Li vs Na) and coordination by PMDETA (N,N,N',N″,N″-pentamethyldiethylenetriamine) play a decisive role in enabling efficient turnovers. Trapping and structural authentication of key metalated intermediates, together with DFT calculations, provide valuable mechanistic insights into the cyclization pathway and the factors governing reactivity. The transformation can proceed catalytically at relatively low loadings in neat conditions, with lithium-based catalysis providing selectively 1,1,4-trimethylcycloheptadienes albeit at higher catalyst loadings of 10 mol%, whereas sodium-based systems can operate at lower loadings of 2 mol% and can promote the isomerization/cyclization of other trienes.

In the present work, we report the synthesis, characterization, biological studies of the nickel(II) complex NiL derived from N 2 O 2 tetradentate Schiff base ligand 2,2'-{(1 E ,1' E )-[1,2-phenylenebis(azanylylidene)]bis(methanylylidene)}bis(5-benzyloxy)phenol L . We used 1 H, FT-IR, for characterization, and the structure of the complex was determined by single crystal X-Ray crystallography. Hirshfeld surface analysis and two-dimensional fingerprint plots of NiL were calculated to quantify the interatomic interactions present in the crystal. On the other hand, The molecular structure of complex was investigated using DFT calculations at the DFT/B3LYP/6-311g (2d,2p)/LANL2DZ level. The interaction between the complex NiL with related target protein (3WZE) receptor was examined using docking experiments. Additionally, the antioxidant activity of the NiL was evaluated by two antioxidant activity assays (DPPH; ABTS) and the enzyme inhibitory potential of the NiL compound was investigated against key enzymes involved in neurodegenerative (acetylcholinesterase (AChE), the α-Glycosidase inhibitory and GST inhibitory activity.

The synthesis of a salen-type ligand functionalized with naphthalene moieties, as well as its precursor, are reported. The compounds were characterized by 1H and 13C NMR, ESI-MS spectrometry and single crystal X-ray diffraction.

A Schiff base ligand, H2L, with two distinct compartments to accommodate a transition and an alkaline earth metal ion was used to synthesize two monometallic, [CuL-(H2O)-(CH3OH)] (1) and [NiL-(H2O)] (2), and six heterometallic complexes, [CuCaL-(NO3)2] (3), [CuSrL-(NO3)2] (4), [CuBaL-(NO3)2]-(H2O) (5), [NiCaL-(NO3)2] (6), [NiSrL-(NO3)2] (7), and [NiBaL-(NO3)2] (8), which were characterized by single crystal X-ray diffraction. Their potential as single-source precursors (SSPs) and their antibacterial properties were investigated. After annealing at 1000 °C in air for 1 h, the complexes (3), (4), (7), and (8) formed the following mixed metal oxides (MMOs): Ca2CuO3 for (3), CuSrO2 and CuSr2O3 for (4), Ni6.64Sr9O21 and Ni2Sr4O9 for (7), and Ni5Ba6O15 for (8). The mixture of two heterobimetallic complexes (3) and (4), (3) and (7), and (4) and (6) allowed the formation of MMOs containing three different metal ions, such as CuCa1.50Sr0.50O3, CuCa0.38Sr0.62O2, and CaCuSrO3. The scanning electron microscopy (SEM) study revealed a sponge-like structure for all the obtained MMOs. The six heterobimetallic complexes showed good solubility in MeOH, DMF, and DMSO. With regard to the antibacterial properties, the protonated ligand and monometallic complex of copper-(II) showed a zone of inhibition (ZOI) that was twice the size of the tested heterobimetallic complexes.

The prediction of cytotoxicity for metal-based drug candidates remains a significant challenge due to the structural diversity and multifactorial mechanisms of action inherent to transition metal complexes. Here, we present an unsupervised machine learning approach employing K-means clustering to cluster the cytotoxicity of 225 rhenium(I) tricarbonyl complexes based solely on molecular descriptors. After comprehensive descriptor calculation and reduction, principal component analysis was used to assess chemical space coverage and identify key variables. K-means clustering, applied without prior toxicity labels, successfully partitioned the data set into cytotoxic and noncytotoxic clusters, achieving high concordance with known biological activity and accurately clustering control compounds. Analysis of misclassified cases provided further insight into structural motifs associated with ambiguous toxicity profiles. This work demonstrates that K-means clustering, when integrated with robust descriptor selection and PCA, offers a transparent, efficient, and interpretable framework for early stage toxicity assessment in metal-based drug discovery, particularly when labeled data are limited.

A novel Schiff base ligand functionalized with a naphthalene moiety has been developed as colorimetric and fluorimetric sensor for the selective detection of multiple metal ions. The coordination of four metal ions (Fe 2+ , Fe 3+ , Co 2+ , and Ni 2+ ) induces an individual color change in solution, while fluorescence is emitted upon the addition of seven other metal ions (Mg 2+ , Ca 2+ , Cd 2+ , Zn 2+ , Al 3+ , Ga 3+ , and In 3+ ). The reliability of the chemosensor was evaluated through competition experiments with a panoply of different cations. The nature of the solvent was revealed to have an impact on the fluorescence properties but not on color changes, whereas the type of counterion did not influence the colorimetric and fluorimetric detection.

We report a comprehensive mechanochemical strategy for the solvent-minimized N-arylation of sulfonamides via C-N coupling using commercially available copper powder as the catalyst and water as a green liquid-assisted grinding (LAG) additive. Inspired by the limitations of traditional solution-phase protocols, such as substrate dependency, over arylation, and poor sustainability, we developed a scalable, efficient and eco-compatible protocol under ball-milling conditions. Initial screening revealed the high thermal reactivity of the masked amine reagent, prompting a shift toward primary sulfonamides as safer and more robust nitrogen nucleophiles. The protocol tolerated a wide range of aryl, heteroaryl, and halogenated boronic acids, affording moderate to high yields, although alkyl and chelating 8-quinolinyl substrates remain challenging. Furthermore, data-driven modeling based on molecular descriptors enabled as an exploratory QSAR tool, which guided successful extension to new substrates. The process was readily scaled to gram quantities and applied to late-stage functionalization of sulfonamide-containing bioactive scaffolds, underscoring its potential as a practical and green synthetic strategy for medicinal and process chemistry applications.

In this study, a library of oxo-rhenium(V) complexes of general formula [Cl3ReO(NN)] bearing diimine ligands was synthesized and fully characterized. The complexes were evaluated for antibacterial activity against Gram-positive and Gram-negative bacteria (MSSA, MRSA, E. coli, and P. aeruginosa). Increasing the lipophilicity of the diimine ligand led to an enhancement in biological activity. The most active compound, bearing NN = bathocuproine (complex 9), exhibited potent activity against S. aureus strains (MIC = 2 µM). Its toxicity profile was assessed in vitro and in vivo: cytotoxicity toward L929 fibroblasts afforded a therapeutic index (TI) of 4.9, while evaluation in the invertebrate model Artemia salina showed only 12.9% lethality at 4× MIC after 24 h, indicating a favorable preliminary safety profile. Mechanistic investigations in MSSA and MRSA revealed strain-specific synergistic interactions of 9 with chloramphenicol and tetracycline in MSSA, and with ampicillin in MRSA, increasing the therapeutic index up to 19.5. Notably, co-administration of sub-inhibitory concentrations of ampicillin and 9 suppressed MRSA growth for more than 72 h. Computational studies suggest that complex 9 may interfere with the β-lactam resistance pathway in MRSA.

Since the isomerization of C-C multiple bonds is a powerful strategy in organic synthesis, in this study we have investigated the isomerization upon metalation of 1-phenylpropyne with alkyllithium bases in the presence of polydentate amine donors. Combining NMR monitoring and X-ray crystallographic studies, we have found that the terminal alkynylide is formed as the major product, can be isolated, and undergoes dimerization upon heating to selectively form an enyne in high yields.

The second ortho-rhom-bic polymorph of the title compound, C21H21N3O2, (I), crystallizes in space group Pna21, compared to Pbca for the first ortho-rhom-bic polymorph (Ii ) [Obasi et al. (2016 ▸). J. Mol. Struct. 1120, 180-186]. The difference in the structure of the two polymorphs resides in the orientation of the 4-meth-oxy moiety of the (4-meth-oxy-phen-yl)allyl-idene unit with respect to the phenyl ring to which it is attached. Compound (I) also exhibits rotational disorder of the phenyl ring of the 4-amino-anti-pyrine moiety. In the crystal of (I), the mol-ecules are linked by C-H⋯O and C-H⋯N hydrogen bonds, forming a three-dimensional network. The conformations, Hirshfeld surfaces, and two-dimensional fingerprint plots of the two polymorphs and closely related structures are compared.

A library of (η6-p-cymene)Ru(II) and Ru(II) bis-bpy complexes bearing thiazolhidrazinylidene-chroman-2,4-dione was synthesized, characterized, and the molecules are evaluated for their antibacterial activity and cytotoxicity. From this library, several compounds are identified as being active against Methicillin-resistant Staphylococcus aureus and Methicillin-sensitive S. aureus. A polypyridyl complex showed a noteworthy minimum inhibitor concentration of 3.1 μm and no toxicity in healthy eukaryotic cells with a therapeutic index of >32. Active complexes appear to exert their antibiotic activity by affecting both the permeabilization of the bacterial membrane and/or the electron transport chain.

In the present work the syntheses, molecular structures and properties of two novel Schiff base N-benzylideneanilines, 4-fluorobenzylidene-4-methoxyaniline (FBMOA) and 4-fluorobenzylidene-4-methylaniline (FBMA), are described. Their structures were confirmed by spectral and crystallographic analyses. FBMA crystallizes with two independent molecules in the asymmetric unit. The interatomic interactions in the crystals of FBMOA and FBMA, that contain different substituents, were investigated through Hirshfeld surface analysis. Thermally, FBMOA and FBMA were found to be stable; FBMOA undergoes bulk decomposition at similar to 180 degrees C and FBMA at similar to 230 degrees C. UV-vis-NIR spectroscopy and open-aperture Z-scan studies were employed to characterize the linear and nonlinear optical behavior of the two compounds. Their structures and properties are compared to those of similar organo halide-substituted Schiff base compounds.

In the present work, the compound imine tautomeric forms in solide state crystalise in keto-amine ( Z )-3 (benzyloxy)-6-(((3-hydroxyphenyl) amino)methylene) cyclohexa-2,4-dien-1-one ( I ). The compound was synthesized via the condensation reaction between the 4-benzyloxy-2-hydroxybenzaldehyde and 1-amino-3-phenol. It was characterized by single-crystal X-ray diffraction analysis, and by infrared, 1 H and 13 C, DEPT-135 and HSQC NMR spectroscopy technicals in powder and solution forms. UV-visible technical confirmed the tautomer phenomenon in different types of solvents. HS analysis and two-dimensional fingerprint plots were used to quantify the interatomic interactions present in the crystal. The molecular structure of compound I in its three tautomeric forms was investigated using DFT calculations at the ωB97X-D/6-311 + G(d) level. Our results exhibit excellent agreement with the optimized geometry and X-ray crystallography structure, with an RMSE of 0.358 Å for I1. Chemical reactivity analysis reveals that I2 is more stable than I1 and I3, and the compounds can be classified as moderate electrophiles. The interaction between the corrosion inhibitor and the copper surface is stronger than with the iron surface in both gas and aqueous phases. Additionally, the first hyperpolarizability decreases in the order I2 > I1 > I3, with $$\:{\beta\:}_{HRS}^{0}$$ values of 992, 557 and 427 a.u., respectively, surpassing the value of urea ( $$\:{\beta\:}_{HRS}^{0}$$ = 38 a.u.). These findings underscore the potential of the title compounds as promising candidates for nonlinear optical applications.

The title centrosymmetric tetra-nuclear cadmium(II) com-plex of 4-amino-anti-pyrine and chloride ions, [Cd4Cl8(C11H13N3O)4]·1.7H2O, was synthesized using methanol as solvent. The two independent Cd2+ ions in the asymmetric unit have different geometries; the outer Cd atoms have fivefold CdONCl3 coordination spheres, while the inner Cd atoms have sixfold CdONCl4 coordination spheres. The com-plex is consolidated by intra-molecular N-H⋯O and N-H⋯Cl hy-dro-gen bonds. In the crystal, a combination of N-H⋯Cl and Ow-H⋯Cl (w = water) hy-dro-gen bonds link the com-ponents to form chains propagating along the a-axis direction. The chains are crosslinked by C-H⋯Cl and C-H⋯O hy-dro-gen bonds to form a three-dimensional structure. A new geometry index, τ6, is proposed to qu-anti-tatively estimate the geometry of a sixfold coordinated atom.

A bimetallic complex based on a salophen-type ligand was synthesized. The compound was characterized by ESI-MS, single-crystal, and powder X-ray diffraction. The heterobimetallic complex was thermally treated to investigate its capacity as a single-source precursor for the formation of mixed metal oxides.

A new tetra­nuclear cadmium(II) com­plex of 4-amino­anti­pyrine and chloride ions was synthesized using methanol as solvent. The com­plex possesses inversion symmetry with two independent Cd2+ ions that have different coordination spheres, one fivefold and the other sixfold. A new geometry index, τ6, is propossed to qu­anti­tatively describe the geometry of a sixfold coordinated atom.

Tubular structures with nanosized pores have shown remarkable applications in areas such as ion transport and water filtration, but their development is often hindered by challenges including low yields, limited functionalization, and poor uniformity. Herein, we present a new series of macrocycles with tuneable diameters and helical foldamers featuring customizable peripheral side chains. The macrocycles, with diameters ranging from 0.8 to 1.4 nm, were synthesized in moderate to good yields using a one-pot method. Solid-state analysis revealed that these macrocycles form nanochannels, highlighting their potential applications in areas such as molecular recognition and artificial water channels (AWCs). Additionally, we synthesized helical aromatic amide polymers with narrow dispersities via a living chain-growth process. Our strategy enables the incorporation of diverse functional groups, including ethers, esters, acids, and amides, on the outer surfaces of the macrocycles or synthetic nanotubes. Circular dichroism (CD) spectroscopy confirmed the helical conformations of the polymers in solution. These macrocycles and foldamers present exciting opportunities for designing bioinspired membrane channels and functional nanotubes with tuneable hydrophobicity and cavity sizes, paving the way for innovative applications in nanotechnology and materials science.

Ring-opening metathesis polymerization (ROMP) is a well-established polymerization method that uses strained cyclic olefins to produce polymers with controlled molecular weight and dispersity suitable for aggregation in solution, leading to polymerization induced self-assembly (PISA). Herein, we report new norbornene-based monomers for the living ROMP that were synthesized on the multigram scale (20 g) starting from cis-5-norbornene-exo-2,3-dicarboxylic anhydride and hydrazine. Upon further reaction with carboxylic acid chlorides, non-hydrogen-bond-forming derivatives could be obtained. In the presence of Grubbs third generation catalyst (G3), the synthesized monomers could be polymerized to produce well-defined polymers with controlled molecular weights (Mn) and narrow dispersities (Đ). Furthermore, amphiphilic block copolymers were synthesized using a combination of acylated and nonacylated monomers, and the PISA behavior was investigated using dynamic light scattering (DLS). We believe that the self-assembly of the copolymers derived from the new norbornene-based monomers via the living ROMP method described here could be useful for developing advanced functional nanomaterials with various morphologies.