Type Of Counterion Research Articles

Effect of Hofmeister and Alkylcarboxylate Anionic Counterions on the Krafft Temperature and Melting Temperature of Cationic Gemini Surfactants

The effect of counterions was investigated to probe the principal ionic effects on the solubility in water and melting behavior of cationic gemini surfactants. We focused on two types of counterions: (1) small inorganic counterions that are typically taken from the Hofmeister series were studied to focus on the effect of ion type and (2) n-alkylcarboxylate counterions were studied to focus on the effect of the hydrophobicity of counterions. The Krafft temperature (Tk) and melting temperature (Tm) were obtained by conductivity measurements, calorimetric measurements, and optical microscopy observation. The results clearly indicate that Tk, which represents the solubility of surfactants, is not determined by a single parameter of ions such as the hydration free energy, as is too often assumed, but rather by the combined effects between the hydrophobicity of anions associated with other effects such as the polarizability, dehydrated ion size, and ionic morphology. In parallel, our observation demonstrated that all of the surfactants showed a transition from a crystalline phase to a thermotropic liquid-crystalline phase at around ca. 70 °C, which transformed to an isotropic liquid phase at around ca. 150 °C, and that the transition temperatures depended strongly on the counterion type. The counterion effects on the solubilization and melting behaviors were then compared with micellization properties that have been reported previously. These results provide new insight into understanding the effect of ions on the delicate balance of forces controlling the solution properties and aggregate morphology of charged amphiphilic molecules. Specifically, the solubilization properties of these cationic surfactants with various counterions were determined mainly by the subtle interplay between the hydration of counterions and the dissociation energies (stability of crystallinity) of the ion pair.

Pyridinium and imidazolium 1,3,4-oxadiazole ionic liquid crystals: a thermal and photophysical systematic investigation

In this study we present the synthesis and complete structural characterization of twenty five 1,3,4-oxadiazole molecules (ionic and non-ionic) with some systematic structural variations, such as number of counterions, number of alkoxy chains, alkyl chain size, type of counterion and its position on the molecule. The thermal and photophysical properties for all compounds were investigated allowing a complete and interesting simultaneous study of the effect of structural changes on these properties. We show that every parameter studied affected both the thermal and photophysical properties. For these bent core molecules, the liquid crystalline behavior was observed only for compounds containing one counterion, SmA (monolayer or bilayer) being the predominant phase. The neutral (non-ionic) compounds and the imidazolium derivatives showed emission at around 360 nm and a high quantum yield, while most of the pyridinium derivatives showed emission at around 530 nm, a low quantum yield and a complex photophysical behavior. In all cases, the quantum yield for the different counterions follows the sequence ClO4− > BF4− > DS− > NO3− > Br−(I−).

Photophysical properties of [Ir(tpy)2]3+-doped silica nanoparticles and synthesis of a colour-tunable material based on an Ir(core)–Eu(shell) derivative

In this study, we report the synthesis and characterization of phosphorescent silica nanoparticles doped with the blue-greenish emitting Ir-tpy complex [Ir(tpy)2]X3 (tpy = 2,2′:6′,2′′-terpyridine; X = PF6− or NO3−). Depending on the type of counterion and the solubility of the complex, three different kinds of Ir(tpy)-doped silica nanoparticles were prepared by the Stober, water-in-oil and direct micelle synthetic approaches. The materials prepared through the Stober and the water-in-oil approaches showed enhanced photochemical stability and higher luminescence efficiency compared to the free Ir-tpy complex. In these cases, the silica matrix hampers the diffusion of O2 and restrains the mobility of the complexes resulting in a decrease of the vibration relaxation and restraining the nonradiative decay. Conversely, for the material prepared by the direct micelle method, in which the structure of silica shows some degree of mesoporosity, the luminescence properties of the Ir-tpy complex remained almost unchanged after silica encapsulation. Additionally, the nanoparticles prepared by the Stober method were chosen to functionalize their surface with a red-emitting Eu(hfac)3-alkoxysilane derivative leading to multicoloured luminescent silica nanoparticles in which the colour of the emission could be tuned by changing the excitation wavelength and where an Ir → Eu energy transfer was evidenced.

Ultra-trace determination of Hg(ii) in drinking water and local Thai liquors using homogeneous liquid–liquid extraction followed by fluorescence quenching of its ternary complex

The method for preconcentration and trace determination of Hg(II) based on the total fluorescence quenching using a 1,10-phenanthroline (1,10-phen) and dichlorofluorescein (DCF) ternary complex after homogeneous liquid–liquid extraction of the metal complex was developed. Hg(II) ions were dissolved in acid and the sample was complexed with an excess amount of diethyldithiocarbamate (DDTC). The complex of Hg(II)–DDTC formed in an aqueous phase and was extracted into a layer of perfluorooctanoic acid dissolved in lithium hydroxide solution, resulting in ∼100 μL of the sediment liquid phase prior to analysis of the ternary complex by spectrofluorophotometry. The optimization conditions were investigated in detail including pH and buffer solution, type of ligand, ionic strength, counter ion and micellar medium. Under the optimized conditions with a preconcentration factor between 15 and 20 using a mixture of 0.2 mol L−1 acetate buffer pH 4.5, 2.5 × 10−3 mol L−1 1,10-phen, 1% (v/v) Triton X-100 and 2.9 × 10−6 mol L−1 DCF in 15 mL final volume, the decrease in fluorescence intensity of the ternary complex was measured against the reagent blank, in the absence of Hg(II) ions, at the excitation and emission wavelengths of 504.0 and 525.0 nm, respectively. The calibration curve was widely linear over the range of 4.0 μg L−1 to 2.0 mg L−1 with a correlation coefficient greater than 0.997. The method recovery of Hg(II) was about 76.9 to 98.2% at a concentration of 250 μg L−1. The relative standard deviation (RSD) was below 5.5% with a detection limit of 1.0 μg L−1. The proposed method was successfully applied for the determination of Hg(II) in drinking water, distilled spirit and fruit wine samples. The results obtained were in agreement with those of FI-HGAAS.

Construction of Multisubstituted Tetrahydropyrans by a Domino Oxa-Michael/Tsuji–Trost Reaction

Biologically significant tetrahydropyrans (THP) were synthesized by a Tandem oxa-Michael/Tsuji-Trost reaction. Different Michael acceptors were investigated, and optimal results in terms of diastereoselectivities and yields were obtained with nitro olefins. The influence of the reaction parameters, substrate patterns, and type of metal counterions on the yield and stereochemical outcome of this process is discussed, and an explanation for the observed stereoselectivities is proposed.

Molecular modeling of polymeric adsorbent media: The effects of counter‐ions on ligand immobilization and pore structure

Molecular dynamics modeling and simulations are employed to study the immobilization of ligands on the surface of the pores of a base porous polymeric matrix. The results show the significant effects that the counter-ions have on the spatial distribution of the density of immobilized ligands as well as on the pore size and pore connectivity distributions of the porous adsorbent medium being constructed. The results for the systems studied in this work indicate that by using doubly charged counter-ions whose numbers during ligand immobilization are half to those of singly charged counter-ions, the ligand immobilization process proceeds faster and the magnitude of local nonelectroneutrality becomes smaller. More importantly, the pore structures of the adsorbent media resulting from the system using doubly charged counter-ions have porous structures that are characterized by more mid-sized pores and higher pore connectivity than the porous adsorbent structures generated by the system employing singly charged counter-ions and, furthermore, the density distribution of the immobilized ligands in the porous structures where doubly charged counter-ions are employed tends to be more uniform laterally and the ligands are surrounded by fewer counter-ions. These characteristics affected by the use of doubly charged counter-ions could provide important advantages with respect to the transport and adsorption of adsorbate biomolecules of interest. Furthermore, the results of this work indicate that the type of counter-ions being used in the ligand immobilization process could represent an additional control variable for affecting the ligand density distribution as well as the pore size and pore connectivity distributions of the porous structure of the adsorbent medium being constructed.

Dispersions of Non-Covalently Functionalized Graphene with Minimal Stabilizer

We demonstrate that functionalized pyrene derivatives effectively stabilize single- and few-layer graphene flakes in aqueous dispersions. The graphene/stabilizer yield obtained by this method is exceptionally high relative to conventional nanomaterial stabilizers such as surfactants or polymers. The mechanism of stabilization by pyrene derivatives is investigated by studying the effects of various parameters on dispersed graphene concentration and stability; these parameters include stabilizer concentration, initial graphite concentration, solution pH, and type and number of functional groups and counterions. The effectiveness of the pyrene derivatives is pH-tunable, as measured by zeta potential, and is also a function of the number of functional groups, the electronegativity of the functional group, the counterion, the relative polarity between stabilizer and solvent, and the distance from the functional group to the basal plane. Even if the dispersion is destabilized by extreme pH or lyophilization, the graphene does not aggregate because the stabilizer remains adsorbed on the surface. These dispersions also show promise for applications in graphene/polymer nanocomposites (examined in this paper), organic solar cells, conductive films, and inkjet-printed electronic devices.

Simultaneous Removal of Phosphate and Nitrate in Wastewater Using High-Capacity Anion-Exchange Resin

The removal of nutrients in wastewater is a critical issue in water treatment because released nutrients can cause serious adverse effects in water systems or the aquatic environment. In this study, a high-performing polymeric anion-exchange resin was developed for the removal of nutrients from wastewater. The resins were prepared by chloromethylation followed by amination under preferred conditions. The resins were investigated for the removal of nutrients such as phosphate, nitrate, and fluoride from water. The density of functional groups on the synthesized resin was approximately 33 % higher than on commercialized resins, and the specific surface area of synthesized resin was increased by approximately tenfold compared with commercialized resins. The adsorption capacity of synthesized resins (AMP16-FeCl3) for anions was 285.8 mg/g, which was approximately three times higher than the capacity of commercialized resin (AMP16-OH). A study of the effects of the types of counterions and functional groups found that resins having hydroxide ion as a counterion showed higher capacity and selectivity for phosphate ion and that dimethylethanolamine as a resin functional group of resin was more efficient than trimethylamine.

Stability investigation of some heteropolyoxotungstate and heteropolyoxomolybdate salts in buffer solutions

Polyoxometalates (POMs) have shown a great potential of antitumor and antiviral activities; take into account, in this work we investigated the stability of a series of heteropolyoxotungstate-amino acids, heteropolyoxomolybdate-amino acids and the corresponding 12-heteropoly acids at different experimental conditions such as pH, buffer concentration, and the type of counter ion using UV–vis spectroscopy. Furthermore, the effect of tyrosine and ornithine were investigated as a counter ion, on the stability of POMs. The results indicated that degradation of these POMs in aqueous solutions follows pseudo-first order reaction kinetics according to the order of H4SiW12O40>H3PW12O40>H4SiMo12O40>H3PMo12O40 for stability with respect to increasing of pH. The stability of POM increases in the presence of these amino acids.

3D Micromorphology Producing within Poly(lactic acid) Skeleton Using Room-Temperature Ionic Liquids: From Particulate, Fibrous or Porous Scaffolds to Beads

We describe herein a three-dimensionally diverse micropatterning of poly(lactic acid), as a biopolymer, using 1-butyl-3-methylimidazolium-based room-temperature ionic liquids (bmim-based RTILs), [bmim]X (X = SbF6, PF6, NTf2, Cl). Utilizing the hydrophobic bmim-based RTILs, [bmim]X (X = SbF6, PF6, NTf2) and a phase separation technique, we were able to produce white and opaque membranes with a three-dimensional structure closely packed with particles (10-50 µm in diameter). The particlulate structure, made by the assistance of [bmim]NTf2 and DCM, interestingly transformed to a fibrous structure by using a cosolvent, e.g., DCM/CF3CH2OH. When we used an increased amount of [bmim]NTf2, the particles were effectively detached and macrosized (100-500 µm in diameter) and the oval-shaped beads were obtained in a powder form. By varying the counter-anion type of the imidazolium-based RTIL, for example from NTf2 � to Cl � , the particulate 3D-morphology was once more transformed to a porous structure. These reserch results could be potentially useful, as a method to fabricate particulate scaffolds, fibrous or porous scaffolds, and beads as a biopolymer device in diverse fields including drug delivery, tissue regeneration, and biomedical engineering.

Exploring the assembly process and properties of novel crosslinker-free hyaluronate-based polyelectrolyte complex nanocarriers

The aim of this work was to study the formulation of pharmaceutically relevant polyelectrolyte complex nanoparticles (NPs) composed of hyaluronic acid (HA) and chitosan (CS) containing no crosslinkers. The influence of polymer mixing ratio, concentration and molecular weight as well as the type of counterion in chitosan salt on properties of the resulting NPs was examined. Formulations and their components were studied by laser light scattering, viscosity, infrared spectroscopy and microscopy. Physical stability, isoelectric points and cytotoxicity of selected NPs were determined. By appropriate modification of HA molecular weight, stable and non-sedimenting NPs were successfully formed. Sonication was found to be an effective method to reduce the molecular weight of HA from 2882±25 to 176±4 kDa with no chemical changes in the HA structure observed. High molecular weight CS formed micron-sized entities at all compositions investigated. Positively and negatively charged NPs were obtained depending on the mixing ratio of the polymers, with CS glutamate NPs yielding more negatively charged particles compared to CS chloride NPs. The smallest NPs (149±11 nm) were formed using HA with molecular weight of 176 kDa. Cytotoxicity of NPs was dependent on environmental pH but HA was found to exert cytoprotective effects on Caco-2 cells.

Counterion effects on protein adsorption equilibrium and kinetics in polymer-grafted cation exchangers

Protein binding equilibrium and mass transfer kinetics are studied for cation exchangers containing charged polymer grafts as well as for a macroporous matrix in pH 5 acetate buffers using sodium, tetra-n-butylammonium (TBAH), arginine, and calcium as counterions and a monoclonal antibody (mAb) as a model protein. Dynamic light scattering shows that there is no significant effect of the counterion type on the mAb aqueous diffusivity. The counterion type also does not affect substantially the structure of the polymer grafts, nor does it affect the stoichiometry of the protein ion exchange process. While no counterion effects are also observed on the protein mass transfer kinetics for the macroporous matrix, very large effects are seen for the polymer grafted matrices with protein adsorption rates increasing dramatically in the order Ca++>Arg+>Na+>TBAH+. This order is the same order in which the relative protein binding strength decreases. Accordingly, the counterions leading to weaker protein binding also lead to faster protein diffusion. Although the quantitative aspects are different, the same trends hold for different proteins (lysozyme and lactoferrin) and for an agarose-based matrix also containing grafted polymers (Capto™ S). The underlying mechanism is qualitatively consistent with protein transport occurring through a hopping process driven by the adsorbed protein concentration within the apparently flexible network structure formed by the grafted polymers. From a practical viewpoint, the results show that improved protein adsorption kinetics in polymer-grafted cation exchanger and, hence, improved performance, can be obtained by selecting particular counterions.

Ecotoxicity and biodegradability of antielectrostatic dicephalic cationic surfactants

Four series of dicephalic cationic surfactants, considered as new antielectrostatic agents have been investigated in order to establish their toxicity and biodegradability. Among them N,N-bis[3,3′-(dimethylamine)propyl]alkylamides, N,N-bis[3,3′-(dimethylamine)propyl]alkylamide dihydrochlorides, N,N-bis[3,3′-(trimethylammonio)propyl]alkylamide dibromides and N,N-bis[3,3′-(trimethylammonio)propyl]alkylamide dimethylsulphates with different hydrophobic chain length (n-C9H19 to n-C15H31) and type of counterion (chloride, bromide and methylsulfate) have been studied. The inhibitory effect against microorganisms has been examined using model gram-positive and gram-negative bacteria, and yeasts. None of the tested surfactants have shown antimicrobial activity against gram-negative bacteria (Escherichia coli, Pseudomonas putida) and yeasts (Saccharomyces cerevisiae, Rhodotorula glutinis) at a concentration below 1000μgmL−1, however some of them were moderately active against gram-positive bacteria (Staphylococcus aureus, Bacillus subtilis). The Microtox® test was successfully applied to measure EC50 values of the studied dicephalic cationic surfactants. Their toxicity to Vibrio fischeri depended upon the alkanoyl chain length with the EC50 values in a range of 2.6–980mgL−1. N,N-bis[3,3′-(dimethylamine)propyl]alkylamide dihydrochlorides 2a–b and N,N-bis[3,3′-(trimethylammonio)propyl]alkylamide dibromides 3a–b comprising n-decanoyl and n-dodecanoyl hydrophobic tails appeared to be the least toxic. Furthermore, the biodegradability under aerobic conditions of 2a–b, 3a–b was evaluated using OECD Method 301F. According to the obtained results 2a, 3a–3b can be considered as almost readily biodegradable and they are not expected to be persistent in the environment. Additionally, partial biodegradation was observed for 2b, indicating its possible biodegradation in wastewater treatment systems.

Modeling of ion-pairing effect in peptide reversed-phase chromatography

The modeling of counterion and organic modifier concentration effects in peptide APIs reversed-phase preparative chromatography is discussed in this manuscript. A stoichiometric retention model based on the counterion binding to the charged functional groups of the peptide is proposed. The model parameters were evaluated using a rather large set of retention data measured in mobile phases with various counterions and acetonitrile concentrations. The model parameters were experimentally validated by a new counterion binding measurement technique. The nmax model parameter value was found to be equal to the peptide net charge, whereas the K model parameter value was found to be specific to the counterion type (i.e. AcO−<H2PO4−<TFA−<PFPA−). The impact of the mobile phase composition on the peptide saturation capacity was also investigated. It was shown that, at low acetonitrile concentration, the peptide saturation capacity was constant for all investigated counterion types and concentrations. On the other hand, at intermediate acetonitrile concentration, the peptide saturation capacity was significantly lower and with a tendency to increase with the counterion concentration. On the whole, the developed model provides a reliable a reliable tool for the design and development of peptide purification processes at the preparative and industrial scale.

Oil-Water Partitioning of a Synthetic Tetracarboxylic Acid as a Function of pH

The oil-water partitioning of a synthetic tetraacid acting as a model compound for indigenous C80-C82 ARN acids has been studied as a function of pH, ionic strength and type of monovalent counterion. Experimental data obtained with ultraviolet-visible and HPLC/UV analyses have been fitted to thermodynamic models based on one, two or four dissociation steps to obtain o/w partition coefficients (K wo ) of the fully protonated acid between chloroform and aqueous solutions, and its apparent acidity constant(s), pK a. As the study is conducted above the CMC of the tetraacid, in general high apparent acidity constants were obtained in the range from 6 to 8 resulting from micellization equilibria. K wo values were obtained in the range from 10−3 to 10−4, and decreasing with increasing salinity. At 50 mM K+, no conclusions could be made regarding the number of distinguishable dissociation steps, while at higher ionic strength (184 mM and 452 mM K+) and at 184 mM Na+ a model with two dissociation steps provided good fits to the experimental data. The first step was found to be given by a pK a ≈ 6.6–6.8 and the second dissociation step at pK a values ≈ 7.8–8.3. The two-step mechanism supports previous results obtained by potentiometric titrations. No significant difference in the o/w behavior was observed when changing the counterion from potassium to sodium. The main partitioning of the tetraacid in the aqueous phase occurred above pH 8, where the fully deprotonated acid was formed.

Outlook on the Phase Equilibria of the Innovative System of “Protected Glycerol”: 1,4-Dioxaspiro[4.5]decane-2-methanol and Alternative Solvents

Fundamental data on 1,4-dioxaspiro[4.5]decane-2-methanol are scarce. This work presents the foremost systematic data on the solubility of 1,4-dioxaspiro[4.5]decane-2-methanol in sustainable solvents such as water and ionic liquids accompanied by the interpretation of interactions occurring in such binary systems. 1,4-Dioxaspiro[4.5]decane-2-methanol, here called protected glycerol, has been synthesized in order to protect the two hydroxyl groups of glycerol, thus avoiding the formation of side products in a specific process. A series of imidazolium salts accompanied by pyridinium, phosphonium, and ammonium ones with various types of counterions were used in this study. The liquid-liquid and solid-liquid equilibrium measurements in binary systems were carried out by using a dynamic method at atmospheric pressure over the temperature range from 273.00 to 378.30 K or below the boiling point of the solvent. Among all tested sustainable solvents, protected glycerol exhibited limited solubility, with only a few of them in the temperature range studied. The majority of the examined ionic liquids, either hydrophilic or hydrophobic, showed complete miscibility with this monohydroxyol. The Fourier-transform infrared (FTIR) spectroscopy studies of solute and solvents showing a miscibility gap and of their mixtures were performed to obtain insight into major inter- and intramolecular interactions in the investigated systems. Furthermore, the differential scanning calorimetry was used for the first time to determine the melting point, the enthalpy of melting, and the temperature and enthalpy of the solid-solid phase transition of 1-allyl-3-methylimidazolium chloride [Amim][Cl]. The results for the solubility of protected glycerol in sustainable solvents can be used to design future alternative reactions, such as telomerization with protected glycerol in ionic liquids for more specific building blocks and extraction/or separation that involves these mixtures.

Extraction Behavior of Cu(II) Ion From Chloride Medium to the Hydrophobic Ionic Liquids Using 1,10-Phenanthroline

The study of liquid-liquid extraction of Cu(II) ion was carried out by using a series of hydrophobic ionic liquids; 1-butyl-3-methylimidazolium hexafluorophosphate ([C4mimPF6]), 1-hexyl-3-methylimidazolium hexafluorophospahate ([C6mimPF6]), 1-butyl-3-methylimidazolium bistrifluoromethylsulfonyl imide ([C4mimNTf2]) and 1-hexyl-3-methylimidazolium bistrifluoromethylsulfonyl imide ([C6mimNTf2]) as extraction phase. Cu(II) prefer to extract into [C4mimPF6] which is the less hydrophobic of ionic liquids. The extraction behavior of Cu(II) ion depends on the type of counterion and the extraction of Cu(II) ion in ionic liquid system proceeds via similar mechanism with a molecular organic solvent. From these results, it was proposed that the extraction of Cu complexes from chloride medium proceeds through ion pair mechanism.

Aggregation Behaviors of Dodecyl Sulfate-Based Anionic Surface Active Ionic Liquids in Water

Halogen-free, low-cost alkyl sulfate-based surface active ionic liquids (SAILs), 1-butyl-3-methylimidazolium dodecyl sulfate ([C(4)mim][C(12)SO(4)]), and N-butyl-N-methylpyrrolidinium dodecyl sulfate ([C(4)MP][C(12)SO(4)]) were easily synthesized through ion exchange reaction. The aggregation behaviors of [C(4)mim][C(12)SO(4)] and [C(4)MP][C(12)SO(4)] in aqueous solution were investigated by surface tension, electric conductivity, and static fluorescence quenching. Both [C(4)mim][C(12)SO(4)] and [C(4)MP][C(12)SO(4)] have rather lower cmc, γ(cmc) values and higher pC(20), π(cmc) values than those reported for the traditional ionic surfactant, sodium dodecyl sulfate (SDS), and imidazolium-based SAIL, 1-dodecyl-3-methylimidazolium bromide ([C(12)mim]Br), with the same hydrocarbon chain length. The thermodynamic parameters evaluated from electric conductivity measurements show that the micelle formation of [C(4)mim][C(12)SO(4)] and [C(4)MP][C(12)SO(4)] is entropy-driven in the temperature range investigated. Lower average aggregation number indicates that the micelles of two SAILs present much looser structure. It is found that both the nature and the ring type of counterions can affect the aggregation behavior in aqueous solution. (1)H NMR results of [C(4)mim][C(12)SO(4)] were used to further verify the mechanism of micelle formation. Hydration ability and steric hindrance of the imidazolium or pyrrolidinium counterion as well as the cooperative hydrophobic interaction of longer alkyl chain of [C(12)SO(4)] anion and comparatively shorter alkyl chain of [C(4)mim] or [C(4)MP] cation are proposed to play critical roles in the aggregation of [C(4)mim][C(12)SO(4)] and [C(4)MP][C(12)SO(4)].

Insight into nucleic acid counterion interactions from inside molecular dynamics simulations is “worth its salt”

Nucleic acids are highly charged polyelectrolytes. Their interactions with counterions are of great importance for their structural stability, conformational behaviour and biological functions. Molecular modelling and simulation techniques, particularly molecular dynamics, have been highly useful for studies of interactions between DNA, water and ions at the molecular level, allowing us to explain many experimental observations, or to obtain information not accessible experimentally. In this review we focus on both atomistic and coarse-grained molecular simulation studies concerning the interactions of DNA with different types of counterions, with emphasis on recent studies, still open questions, limits of the method and possible further developments.

Synthesis and Determination of Stability Constants of a New Bis-1,2,4-triazole Ligand for Complexation with Zinc(II), Copper(II) and Nickel(II) in Acetonitrile

In this work, the synthesis and complexation properties of a new compound, 1,3-bis[5-(2-hydroxyphenyl)-4-phenyl- 1,2,4-triazole-3-yl-thio]propane (BTP), towards certain transition metal ions, (M(II) where M = Zn, Cu, Ni) in acetonitrile is reported. A hard-modeling strategy was applied to UV-Visible spectroscopy data obtained from monitoring the reaction between BTP and the selected metal ions to determine the concentration profiles of each species and the corresponding stability constant(s) of the complex(es). The stability constants of complexes are always defined in terms of their free metal, free ligand and complexed forms. These constants are influenced by parameters such as the type of metal, ligand, counterion or solvent. In this study, the formation constants of the complexes were determined for the synthesized ligand with several metallic cations in acetonitrile solvent by UV-Vis spectrophotometry.