Metal-ligand Complexes Research Articles

Anagostic Axial Interactions Inhibit Cross‐Coupling Catalytic Activity in Square Planar Pyridinophane Nickel Complexes

AbstractHerein, we report for the first time the use of the nitrogen‐based bidentate molecule [2.2]pyridinophane (N2) as a ligand for metal complexes. Additionally, its improved synthesis allows for electronic modification of the pyridine rings to access the new para‐dimethylamino‐[2.2]pyridinophane ligand (p‐NMe2N2). These ligands bind nickel in an analogous fashion to other pyridinophane ligands, completing the series of tetra‐, tri‐, and bidentate pyridinophane‐nickel complexes. The new compounds exhibit geometrically enforced C−H anagostic interactions between the ethylene bridge protons and the nickel center that are not present in other pyridinophane systems. These ethylene bridge groups also act as an unusual form of steric encumbrance, enforcing square planar geometries in ligand fields that would otherwise adopt tetrahedral structures. In addition, these anagostic interactions inhibit the catalytic performance in Csp3–Csp3 Kumada cross coupling reactions relative to other common bidentate N‐ligand platforms, possibly by preventing the formation of the 5‐coordinate oxidative addition intermediates.

Synthesis of Metal Complexes of Substituted Isonicotinohydrazide and their Catalytic and Biological Activities

Coordination chemistry has fascinated and inspired chemists all over the world due to an increasing academic, industrial, and biological interest in metal complexes of organic chelating ligands. Among the chelating ligands, Schiff bases have attracted the attention of chemists due to ease of preparation and complexation. Numerous reports showed that a large number of isatin and its Schiff base metal complexes have excellent catalytic activity in a variety of reactions at mild reaction conditions and are used as homogeneous catalysts. Copper-based isatin complexes have found much attention because of their biological relevance. In this study, we report the synthesis of Schiff base metal complexes of substituted isonicotinohydrazide. The Schiff base, (C14H10N4O2) is prepared by condensing isoniazid with isatin. The complexes were synthesized in good yield from easily available metal precursors and characterized by UV-visible and FTIR spectroscopy. The Cu complex shows excellent activity for the C-N coupling reaction of the amination of aryl halides. All four complexes show better antibacterial activity as compared to their corresponding [M (acac)n] complexes. In addition to this, the Co and Cu complexes such as [Co(C14H10N4O2)3] and Cu(C14H10N4O2)3] respectively show negative growth, towards Fusarium, and Aspergillus i.e. showing antifungal activity. The results were compared with the standard acetyl-acetone complexes of the same metals.

Impact of Sodium Dodecyl Sulfate Anionic Micelles on the Complex Equilibria of Divalent Metal Ions with 5-Sulfosalicylic Acid

The potentiometric measurement was conducted to determine the formation of metal-ligand complex species between 5-sulfosalicylic acid and divalent calcium, magnesium and zinc metal ions. The experiment involved varying concentrations of sodium dodecyl sulphate (0.0, 0.5, 1.0, 1.5, 2.0 and 2.5 percent w/v). The experimental procedure was conducted at a temperature of 303 Kelvin, utilizing sodium chloride (NaCl) to regulate the ionic strength to a value of 0.16 moles per cubic decimeter. The dynamic species of 5-sulfosalicylic acid are LH2- and LH2-. The selection of the best fit for the complex speciation was based on statistical criteria including skewness, χ2, kurtosis and crystallographic R-factor. The formation of the complexes ML2H, ML2H2 and ML3H3 was seen upon as the complexation of metal ions with 5-sulfosalicylic acid. The relationship between electrostatics and the stability of complex species has been demonstrated. Additionally, the dispersion of chemical species in relation to pH and compositional variety has been observed. This study investigates the potential existence of intricate equilibria.

Prediction of stability constants of metal-ligand complexes by machine learning for the design of ligands with optimal metal ion selectivity.

The new LOGKPREDICT program integrates HostDesigner molecular design software with the machine learning (ML) program Chemprop. By supplying HostDesigner with predicted logK values, LOGKPREDICT enhances the computer-aided molecular design process by ranking ligands directly by metal-ligand binding strength. Harnessing reliable experimental data from a historic National Institute of Standards and Technology (NIST) database and data from the International Union of Pure and Applied Chemistry (IUPAC), we train message passing neural net algorithms. The multi-metal NIST-based ML model has a root mean square error (RMSE) of 0.629 ± 0.044 (R2 of 0.960 ± 0.006), while two versions of lanthanide-only IUPAC-based ML models have, respectively, RMSE of 0.764 ± 0.073 (R2 of 0.976 ± 0.005) and 0.757 ± 0.071 (R2 of 0.959 ± 0.007). For relative logK predictions on an out-of-sample set of six ligands, demonstrating metal ion selectivity, the RMSE value reaches a commendably low 0.25. We showcase the use of LOGKPREDICT in identifying ligands with high selectivity for lanthanides in aqueous solutions, a finding supported by recent experimental evidence. We also predict new ligands yet to be verified experimentally. Therefore, our ML models implemented through LOGKPREDICT and interfaced with the ligand design software HostDesigner pave the way for designing new ligands with predetermined selectivity for competing metal ions in an aqueous solution.

Novel terephthalaldehyde bis(thiosemicarbazone) Schiff base ligand and its transition metal complexes as antibacterial Agents: Synthesis, characterization and biological investigations

The synthesis and structural characterization of mixed ligand metal complexes from terephthalaldehyde bis(thiosemicarbazone) (TPTSC) (L1) and alanine (L2) by using ultrasonication are reported. The ligand and their transition metal complexes were characterized on the basis of their elemental, FT-IR, magnetic moment, molar conductance, mass spectra, and SEM analysis. The mixed ligand complexes are in the ratio 2:1:2 [M:L1:L2] ratio as found from the elemental analyses and found to have the formulae [M2L1(L2)2].nH2O where M = Co(II), Ni(II), Cu(II), Cd(II) and Zn(II), L1 = TPTSC and L2 = alanine. The molar conductance data show that complexes are non-electrolytes. FT-IR spectra show that the Schiff base is coordinated to the metal ions in a bidentate manner with N and S donor sites of the terephthalaldehyde bis(thiosemicarbazone) and second ligand alanine coordinated to the metal ions via its N and O of amino acid. The geometrical structure of these complexes is found to be tetrahedral. The antimicrobial activity of the synthesized Schiff base ligand and mixed-ligand metal complexes have been screened against gram-positive and gram-negative bacteria and two fungi species were tested. Mixed ligand complexes exhibited significant antibacterial activity against Klebsiella Pneumoniae, Salmonella typhi, Enterococcus Faecalis, Staphylococcus aureus, Escherichia coli and the fungi Aspergillus flavus and Aspergillus niger. Further, these compounds have been screened for their anticancer activity using Human Breast Cancer Cell Line MDA-MB-231.

A triradical-containing trinuclear Pd(II) complex: spin-polarized electronic transmission, analog resistive switching and neuromorphic advancements.

Neuromorphic computation has emerged as a potential alternative to subvert the von Neumann bottleneck issue in conventional computing. In this context, the development of resistive switching-based memristor devices mimicking various synaptic functionalities has engendered paramount attention. Here, we report a triradical-containing trinuclear Pd(II) cluster with a cyclohexane-like framework constituted by the Pd-Se coordination motif displaying facile memristor property with neuromorphic functionality as a thin-film device. The metal-ligand complex (complex 1) possessed an St = 1/2 ground state by experiencing a spin-frustrated-type magnetic coupling phenomenon amongst the three ligand-based organic radicals (SR = 1/2), coordinated to the Pd(II) ions. Three reversible one-electron reduction waves countered with a one-electron and one two-electron reversible oxidation waves were noticed in the cyclic voltammogram of the complex, confirming electrons accepting and releasing capacity of the complex at low potentials, i.e., within +0.2 V to -1.1 V. Employing the radical-containing complex 1 as the active thin-film sandwiched between two orthogonal electrodes, resistive switching based memristor property with biological synaptic actions were successfully emulated. Intriguingly, the artificial neural network (ANN) simulated efficient pattern recognition demonstrated using the recorded potentiation and depression curves from the device, which is a step ahead for the hardware realization of neuromorphic computing. The performance of the ANN on MNIST data with reduced image resolution has further been evaluated. Density functional theory (DFT)-based theoretical calculation predicted that the spin-polarized electronic transmission substantiated the memristive property in the neutral complex 1.

Unveiling the ion sensing capabailities of 'click' derived chalcone-tailored 1,2,3-triazolic isomers for Pb(ii) and Cu(ii) ions: DFT analysis.

In this study, two novel chalcone-derived 1,2,3-triazole-appended positional isomers (probe 6 and probe 9) were synthesized via the 'CuAAC' (Cu(i) - catalysed alkyne azide cycloaddition) methodology for the purpose of metal ion detection. The synthesized probes underwent characterization utilizing standard spectroscopic methodologies including FTIR, NMR (1H and 13C), and mass spectrometry. Subsequently, the sensing capabilities of these probes were explored using UV-Vis and fluorescence spectroscopy, wherein their selective recognition potential was established for Pb(ii) and Cu(ii), both of which can pose serious health hazards when prevalent in the environment above permissible limits. Both the probes exhibited fairly low limits of detection (LoD), determined as 5.69 μM and 6.55 μM in the case of probe 6 for Pb(ii) and Cu(ii) respectively; whereas the probe 9 exhibited an LoD of 5.06 μM and 7.52 μM for Pb(ii) and Cu(ii), respectively. The job's plot for the probe demonstrates the formation of a 1 : 1 complex between the metal and ligand. Furthermore, the interaction of the free probes with the metal ions in the metal-ligand complex was elucidated through 1H NMR analysis and validated theoretically using Density Functional Theory (DFT) simulations with the B3LYP/6-311G++(d,p) and B3LYP/LANL2DZ basis sets for geometry optimization of the probes and their corresponding metal complexes. These findings offer a reliable approach to Cu(ii) and Pb(ii) ion detection and can be further used for the potential applications in environmental monitoring and analytical chemistry.

Reversible C-C bond formation in group 4 metal complexes: nitrile extrusion via β-aryl elimination.

Pyridylamides of zirconium and hafnium with [C,N,N]-ligands reversibly insert nitriles into M-CAr bonds leading to an observable equilibrium between the starting [C,N,N]-complexes and newly formed [N,N,N]-complexes with a ketimide moiety in a 7-membered metallacycle. The discovered reversible insertion of nitriles into M-CAr bonds represents an unprecedented example of β-aryl elimination from a ketimide ligand in early transition metal complexes. Experimental and computational studies suggest thermodynamic and electronic reasons for this reactivity. Weak orbital overlap between the ketimide nitrogen and the metal, and an unfavorable 7-membered metallacycle destabilize the product of insertion into the M-CAr bond, while the pyridylamide moiety acts as a directing group making the reverse process viable. The influence of non-chelate spectator ligands on the metal center and substituents in nitrile on the thermodynamic stability of the [N,N,N]-complexes was also studied. Exploiting β-carbon elimination in complexes of early transition metals may extend the range of catalysts that are accessible for C-C activation processes in the future.

Metal centers and aromatic moieties in Schiff base complexes: impact on G-quadruplex stabilization and oncogene downregulation

We present the synthesis and characterization of novel square planar transition metal complexes of Schiff base ligands, which act as guanine quadruplex binders and stabilizers.

Manganese(II) and Zinc(II) metal complexes of novel bidentate formamide-based Schiff base ligand: synthesis, structural characterization, antioxidant, antibacterial, and in-silico molecular docking study.

A new bidentate Schiff base ligand (C16H16Cl2N4), condensation product of ethylene diamine and 4-chloro N-phenyl formamide, and its metal complexes [M(C16H16Cl2N4)2(OAc)2] (where M = Mn(II) and Zn(II)) were synthesized and characterized using various analytical and spectral techniques, including high-resolution mass spectrometry (HRMS), elemental analysis, ultraviolet-visible (UV-vis), Fourier-transform infrared (FTIR) spectroscopy, AAS, molar conductance, 1H NMR, and powder XRD. All the compounds were non-electrolytes and nanocrystalline. The synthesized compounds were assessed for antioxidant potential by DPPH radical scavenging and FRAP assay, with BHT serving as the positive control. Inhibitory concentration at 50% inhibition (IC50) values were calculated and used for comparative analysis. Furthermore, the prepared compounds were screened for antibacterial activity against two Gram-negative bacteria (Staphylococcus aureus and Bacillus subtilis) and two Gram-positive bacteria (Escherichia coli and Salmonella typhi) using disk-diffusion methods, with amikacin employed as the standard reference. The comparison of inhibition zones revealed that the complexes showed better antibacterial activity than the ligand. To gain insights into the molecular interactions underlying the antibacterial activity, the ligand and complexes were analyzed for their binding affinity with S. aureus tyrosyl-tRNA synthetase (PDB ID: 1JIL) and S. typhi cell membrane protein OmpF complex (PDB ID: 4KR4). These analyses revealed robust interactions, validating the observed antibacterial effects against the tested bacterial strains.

A dual-functional rhodamine B and azo-salicylaldehyde derivative for the simultaneous detection of copper and hypochlorite: synthesis, biological applications and theoretical insights.

A multifunctional rhodamine derivative containing azo-salicylaldehyde (BBS) was designed and synthesized as a colorimetric and fluorescence turn-on probe for the selective detection of copper cations (Cu2+) and hypochlorite anions (OCl-) in aqueous media. In the presence of Cu2+, the probe BBS exhibited turn-on absorption and fluorescence change at 554 nm and 585 nm, respectively. The binding mechanism of BBS with Cu2+ induces the opening of a spirolactam ring in the rhodamine moiety by the formation of a metal-ligand complex, achieving 10-fold enhancement in fluorescence and quantum yield, along with a binding constant of 1 × 104 M-1 and a detection limit of 2.61 μM. Addition of OCl- enhanced the absorbance and fluorescence intensities at 520 nm and 575 nm, respectively. The probe BBS underwent hypochlorite-mediated oxidation, followed by hydrolysis, resulting in the formation of rhodamine B itself, which is detectable by the naked eye via the color and fluorescence enhancement by 11-fold with a high quantum yield and a detection limit of 1.96 μM. For practical applications, sensor BBS can be used to detect Cu2+ in water samples and on cotton swabs. For biological applications, the interaction of the BBS-Cu(II) complex with transport proteins such as bovine serum albumin (BSA) and ct-DNA was investigated through UV-vis and fluorescence titration experiments. Additionally, the structural optimization of BBS and the BBS-Cu(II) complex was demonstrated using DFT, and the interactions of the BBS-Cu(II) complex with BSA and ct-DNA were analysed through theoretical docking studies. Bioimaging studies were conducted by capturing fluorescence images of BBS with Cu2+ and OCl- in a physiological medium containing living plant tissue using green gram seeds.

DESIGN, ANALYSIS, AND ANTIMICROBIAL EXPLORATION OF TRANSITION METAL COMPLEXES WITH TRIDENTATE SCHIFF BASES

The hydrazone Schiff base ligand, 1-(2,5-dihydroxyphenyl) propylidene) pyrazine-2-carbohydrazide, was synthesized by condensing equimolar amounts of 2,5-dihydroxypropiophenone and pyrazine-2-carbohydrazide in ethanol. This ligand was then reacted with various metal chlorides to form complexes with Fe (III), Ti (III), Cr (III), Th (IV), VO (IV), MoO₂(VI), and WO₂(VI). The synthesis followed an established protocol. These metal-ligand complexes exhibited notable antimicrobial activity. Scanning Electron Microscopy (SEM) was used to study their shape, while X-ray diffraction (XRD) confirmed the structure of the complexes as nano-crystalline.

PKaH values and θH angles of phosphanes to predict their electronic and steric parameters.

Phosphanes play an important role in various applications, serving as a class of organic bases with basicities spanning more than 30 orders of magnitude. Accessing comprehensive basicity data for phosphanes has been challenging due to scattered information across multiple sources and notable gaps in the existing data. In this report, we present basicities (pKaH values) of a diverse set of phosphanes, both newly measured or calculated and collected from the literature. We demonstrate that pKaH values can serve as an alternative to Tolman electronic parameters (TEP values) in evaluating the electronic properties of phosphanes. Additionally, we suggest parameters for assessing the steric properties of phosphanes without the need for preparation or calculation of metal-ligand complexes.

Rapid nucleation and optimal surface-ligand interaction stabilize wurtzite MnSe.

Non-native structures (NNS) differ in discrete translational symmetry from the bulk ground state native structure (NS). To explore the extent of deconvolution of various factors relevant to the stabilization of the wurtzite/NNS of MnSe via a heat-up method, we performed experiments using various ligands (oleic acid, oleylamine, octadecylamine, stearic acid, and octadecene), solvents (tetraethylene glycol and octadecene), and precursor salts (manganese chloride and manganese acetate). Experiments suggest that oleic acid in the presence of tetraethylene glycol and oleylamine in the presence of octadecene stabilize wurtzite/NNS. Further, density functional theory (DFT) computations explore the interaction between the functional groups in ligands and the most exposed surfaces of wurtzite/NNS and rocksalt/NS polymorphs. Computations suggest that the interactions between relevant surface facets with carboxylic acid and the double bond functional groups suppress the phase transformation from NNS to NS. In addition, the ionizability of the precursor salt also determines the rate of formation of the metal-ligand complex and the rate of nucleation. Consequently, the formation rate of the Mn-ligand complex is expected to be greater in the case of chloride salt than acetate salt because the chloride salt has higher ionizability in ethylene glycol. From the above, we conclude that the kinetics of the wurtzite/NNS to rocksalt/NS phase transformation depends mainly on two factors: (1) nucleation/growth kinetics which is controlled by the ionizability of the precursor salt, solvent, and stability of the metal-ligand complex, and (2) the activation energy barrier of the NNS to NS conversion which is controlled by surface energy minimization with the ligand.

Modelling ligand exchange in metal complexes with machine learning potentials.

Metal ions are irreplaceable in many areas of chemistry, including (bio)catalysis, self-assembly and charge transfer processes. Yet, modelling their structural and dynamic properties in diverse chemical environments remains challenging for both force fields and ab initio methods. Here, we introduce a strategy to train machine learning potentials (MLPs) using MACE, an equivariant message-passing neural network, for metal-ligand complexes in explicit solvents. We explore the structure and ligand exchange dynamics of Mg2+ in water and Pd2+ in acetonitrile as two illustrative model systems. The trained potentials accurately reproduce equilibrium structures of the complexes in solution, including different coordination numbers and geometries. Furthermore, the MLPs can model structural changes between metal ions and ligands in the first coordination shell, and reproduce the free energy barriers for the corresponding ligand exchange. The strategy presented here provides a computationally efficient approach to model metal ions in solution, paving the way for modelling larger and more diverse metal complexes relevant to biomolecules and supramolecular assemblies.

A new family of macrocyclic antibiotics based-on Pillar[5]arene concluding multi quinoline moieties

Due to the many negative effects of increasing resistance to traditional antibiotics on living organisms, the development of new antibiotic classes has become imperative and macrocyclic compounds come to the fore for the solution of this problem. In this paper, the Pillar [5]arenes including ten and five quinoline units were synthesized and characterized by some procedures such as magnetic susceptibility, FT-IR, elemental analyses, 1H NMR, 13C NMR, melting point. Moreover, zinc(II) and copper (II) complexes were prepared to compare the antimicrobial effects with macrocyclic ligands. In the complex compounds, the metal:ligand ratios were determined with Job method as 1:2 and 1:1 for deca and penta units, respectively. The magnetic properties of the copper (II) complexes are 1.83 BM and 1.87 BM while zinc complexes have a diamagnetic character. The target macrocyclic ligands (Compound 7 and 8) and their metal complexes (Cu(II) and Zn(II)) were screened for the antimicrobial properties against the bacterial strains of Escherichia coli ATCC 25922, Staphylococcus aureus (MRSA) ATCC 43300, Klebsiella pneumoniae. ATCC 70603, Salmonella enteritidis ATTC 13076, Pseudomonas aeruginosa ATCC 27853, Bacillus cereus ATTC 11778, Sarcina lutea ATCC 9341, and yeast Candida albicans NRRL Y-417 by using broth microdilution method. Compound 7 has the optimum MIC values for S. aureus (MRSA), B. cereus, C. albicans and P. aeruginosa microorganisms that they were determined as 23.43, 46.87, 93.75 and 187 μg/mL, respectively. Moreover, Compound 8-Cu(II) complex was defined as an excellent antimicrobial agent against MRSA, B. cereus and C. albicans strains that the MIC values were determined as 3.9 μg/mL for both bacteria. The metal complexes of the target macrocyclic ligands have a more antimicrobial effect than the reactants and the target macrorings. Moreover, they have more successful results for Gram positive derivatives rather than Gram negative microorganisms.

Role of aurone ligands in microwave enhanced Mn (II) and Co (II) catalyzed dehydrogenative coupling reaction: An efficient ligand for the synthesis of quinoline, pyridine, and pyrrole

AbstractThe role of new series of phosphine‐free aurone ligands have been investigated in microwave‐enhanced Mn (II) and Co (II) dehydrogenative coupling reactions. Various heterocyclic compounds such as Quinoline, pyridine, and pyrrole have been synthesized and characterized by NMR spectroscopy. The synthesized ligands (L1–L4) with Mn(II) and Co (II) salt showed excellent catalytic activity and proved to be very effective for the dehydrogenative coupling reaction. This synthetic method involves the in‐situ formation of a metal ligand complex that was analyzed by mass spectrometry. A broad range of substrates including aliphatic ketone, heterocycles, and sterically hindered Ketone coupling partners are well tolerated in the developed protocol.

Designing Metal Complexes for Redox Flow Batteries By High-Throughput Synthesis

Redox flow batteries (RFBs) are an attractive device for high-capacity energy storage systems. Due to the disadvantages of vanadium RFBs such as high cost and limited temperature operability [1], researchers have been developing new redox couples to replace vanadium. The use of relatively inexpensive transition metals (Fe, Cr, Co, etc.) in combination with ligands to form metal-ligand complexes has received considerable attention [2]. The redox potential of a metal ion of a metal-ligand complex can be tuned by forming a complex with a ligand, and the metal-ligand complex form helps alleviate the crossover problem [3].A major challenge in the discovery and development of functional materials is to find and select the most optimized candidates from millions of possible materials [4]. High-throughput Synthesis (HTSy) enables simultaneous screening, synthesis and characterization of a large number of different material classes, providing unprecedented throughput and reproducibility. Therefore, HTSy can save energy, time, and cost for more efficient discovery of advanced functional materials [5]. In this study, based on HTSy methods, we used an automatic synthesis device (OT-2 liquid pipetting robot) to mix and heat metals (Ni, Cr, Cu, etc.) and ligand liquids to automatically design metal complexes. At the same time, a robot platform is developed to perform high-throughput electrochemical tests to quickly select suitable metal complexes for RFBs, and then conduct further related RFBs performance tests.

A critical review of the quantification, analysis and detection of radionuclides in the environment using diffusive gradients in thin films (DGT): advances and perspectives

Abstract This critical review explores the quantification, analysis, and detection of radionuclides in the environment using the diffusive gradients in thin films (DGT) technique. Radionuclides, unstable isotopes emitting ionising radiation, are present in the environment due to natural and anthropogenic sources for which concerns are raised about their impact on human health and ecosystems. DGT offers a unique passive sampling approach for understanding the behaviour of radionuclides and other trace elements. This review provides insights into method development, real case scenarios, advantages, limitations, and future perspectives of DGT in radionuclide analysis. In terms of method development, various isotopes have been analysed with varying significance based on origin, concentration, risks, and persistence. Notably, U, Th, Pu, Am, Cm, 99Tc, 226Ra, 137Cs, 134Cs, 232U, 237Np, and 152Eu have been measured, revealing their diverse roles in environmental radioactivity. Real case scenarios illustrate applications in uranium mining, water quality monitoring, and metal speciation studies, shedding light on mobility, bioavailability, and ecological impacts. DGT’s advantages include in-situ monitoring, time-averaged mean concentrations, and comprehensive speciation insights. Challenges include potential influences from biofouling, temperature changes and specifically the possible degradation of the binding and diffuse layer due to ionising radiation in long term exposures. In addition, the distinction between fully labile free metal ions and partially labile metal-ligand complexes introduces a potential limitation in the DGT technique, hence being an opportunity for future studies. Looking forward, DGT is expected to contribute to radiation dose modelling, environmental risk assessment, and water quality monitoring, with ongoing developments enhancing its utility and accuracy.

Design and synthesis of acyclic bis-triazole ligands: Complexation with metal ions, DFT calculations, and biological activity

Triazole-derived heterocyclic compounds have significant biological activities and pharmaceutical stability. A new series of acyclic bis-triazole ligands 16–20 with ester end groups were designed. The synthesized ligands were evaluated for their complexation ability with transition metals (Cu2+, Hg2+, Pb2+, and Zn2+). The molar conductivity of bis-1,2,3-triazole ligand-metal complexes was measured in acetonitrile at a temperature range 288.15–308.15 K. Furthermore, the thermodynamic quantities (∆H°, ∆S°, and ∆G°) were determined using the van't Hoff equation and the computational stability constants of the resulting 1:1 complexes were determined based on 1:1 stoichiometry. Meanwhile, the optimized geometry of ligands and ligand-metal complexes was computationally calculated using density fraction theory (DFT). Moreover, the antioxidant potential, in DPPH and ABTS assays, as well as the antibacterial activity of the bis-1,2,3-triazole ligands were evaluated. Ligands 16, 19, and 20 complexed with Hg2+ as well as ligand 17 with Cu2+, Hg2+, and Pb2+ showed a continuous decrease in molar conductivity on complexation, however, ligand 18 complexed with Cu2+, Hg2+, Pb2+, and Zn2+ begins to level off at a mole ratio of 1:1 (ligand:metal) indicating the formation of stable complexes. Noteworthy, ligand 17 formed a 1:2 and 2:1 ligand-to-metal ratio with Hg2+ and Pb+2 cations, respectively. The formation reactions of all ligand-metal complexes were exothermic and spontaneous indicating a strong triazole-metal interaction based on ∆H° and ∆G° values. Bis-triazole ligands 16–20 revealed antioxidant activity with IC50 values ranging from 89.0 to 156.1 µg/ml in DPPH and 91.3–167.2 µg/ml in ABTS assays. Ligands 16–19 exhibited antibacterial activity against the Gram-positive Bacillus cereus with MICs ranging from 150 to 250 µg/ml. The synthesized bis-triazole ligands have a potential application in the pharmaceutical and food industries. Moreover, the selectivity of ligands 16, 19, and 20 to Hg2+ could be useful for removing such a metal from industrial wastewater containing a variety of toxic heavy metals and ISE construct.