Triazolium Cations Research Articles

1-Ethyl-4-isopropyl-1,2,4-triazolium bromide.

An ionic compound consisting of a triazolium cation and bromide anion, C7H14N3 +·Br-, has been synthesized and structurally characterized using single-crystal X-ray diffraction and NMR. The compound crystallizes in the monoclinic space group P21/m with the non-hydrogen atoms of one cation lying on general positions and the others lying on a mirror plane. One bromide ion also lies on the mirror. The extended structure exhibits only weak inter-molecular inter-actions between heterocyclic C-H groups and Br- ions.

Cover Image, Volume 61, Issue 5

Journal of Polymer ScienceVolume 61, Issue 5 p. i-i COVER IMAGEFree Access Cover Image, Volume 61, Issue 5 First published: 01 March 2023 https://doi.org/10.1002/pol.20230065AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Graphical Abstract The paper of J. Radicke et al. reports on the solubility of cellulose - a chiral polymer - in six different ionic liquids (IL) at roomtemperature. The ILs are basesd on imidazoliumand 1,2,3- triazolium cations, respectively, and lactates as chiral or racemic anions. Employing molecular dynamics simulations, a semi-quantitative prediction of the cellulose solubility in ILs with anions of different chirality is obtained based on the hydrogen bond formation. (DOI: 10.1002/pol.20220687) Volume61, Issue51 March 2023Pages i-i RelatedInformation

1-Amino-5-nitriminotetrazole: Effective Interaction of N-Nitro and N-Amino Functionalities for Outperforming and Applicable Energetic Materials

1-Amino-5-nitriminotetrazole is synthesized for the first time via acid-catalyzed protection of 1,5-diaminotetrazole with acetone followed by aprotic nitration using N2O5 and in situ deprotection. The salts of 1-amino-5-nitriminotetrazolate are synthesized by addition of the corresponding bases. Most of the nitrogen-rich salts show insane explosive properties and compete with the most powerful non-nuclear explosives. The implementation of a fused triazolium cation yields a promising secondary explosive, with high performance but also low sensitivity and high thermal stability. Metal salts (K and Ag) are successfully used to initiate pentaerythritol tetranitrate using a classical detonator setup.

Dicationic ionic liquids (DILs) based on the phenyl and perfluoro-phenyl π-spacer-linked triazolium cations: a quantum chemical comparative study

Dicationic ionic liquids (DILs) based on the phenyl and perfluoro-phenyl π-spacer-linked triazolium cations: a quantum chemical comparative study

Conductive and Stable Crosslinked Anion Exchange Membranes Based on Poly(arylene ether sulfone)

Highly conductive and stable anion exchange membranes (AEMs) are important components of high-performance anion exchange membrane fuel cells (AEMFCs). Here, we report the use of crosslinked poly(arylene ether sulfone) (PAES) AEMs containing quaternary ammonium (QA) and triazolium cations. The crosslinked PAES-triazole-hydroxide membrane (cPAES-TA-OH) had a higher ion exchange capacity (IEC) than that of the non-crosslinked membrane (PAES-TA-OH) owing to the presence of triazolium cations. The IEC values of cPAES-TA-OH and PAES-TA-OH were 1.75 and 1.31 meq/g, respectively. The IEC value affects the water uptake and swelling ratio of a membrane. The water uptake and swelling ratio of cPAES-TA-OH were higher than those of PAES-TA-OH at 30 °C and 80 °C. In addition, hydroxide conductivity and membrane stability were enhanced by crosslinking; the hydroxide conductivity of cPAES-TA-OH was 92.1 mS/cm at 80 °C under 95% RH (in contrast to 86.2 mS/cm for PAES-TA-OH), and its conductivity retention was 67% after treating with 1M NaOH at 80 °C for 24 h (in contrast to 51% for PAES-TA-OH).

Effects of repeat unit charge density on the physical and electrochemical properties of novel heterocationic poly(ionic liquid)s

The higher the charge density of PILs the higher their Tg and the lower their conductivity; the best conductivity (1.8 × 10−5 S cm−1 at 25 °C): PILs with triazolium cations; the best cathodic stability (−0.4 V vs. Li+/Li at 70 °C): PILs with mixed type cations.

Effects of Nitridation and Vinylation of Imidazolium Rings on Hydrogen Bonding Interactions, π-π-Stacking Structures, and Dynamical Heterogeneities in Imidazolium and Triazolium Ionic Liquids.

Extensive atomistic simulations have been performed to investigate how nitridation and vinylation of cations affect hydrogen bonding structures and dynamics, π-π-stacking interactions between cation-ring planes, and translational and rotational dynamics of ion species in ionic liquids (ILs) consisting of bis(trifluoromethylsulfonyl)imide anions coupled with either imidazolium or triazolium cations. Both nitridation and vinylation of cations have remarkable effects on molecular electrostatic potential contours of cations and polarities of cation-ring hydrogen atoms, leading to distinct structures and dynamics in their hydrogen bonding associations with representative atoms in anions and in triazolium cations. Both imidazolium- and triazolium-ring planes exhibit varied π-π-stacking structures depending on nitridation positions on imidazolium rings. The vinyl-substituted cations have more prominent π-π-stacking interactions than their methyl-based counterparts because of the formation of π-conjugated ring vinyl moieties. Polar and apolar groups in ion species exhibit remarkable translational and rotational dynamics and distinct diffusion distributions in IL matrices at different timescales. The nitridation and vinylation of cations lead to enhanced deviation of translational mobilities of ion species from Gaussian behavior, and cations have a higher degree of dynamical heterogeneity than their coupled anions.

Interaction of supported ionic liquids phases onto copper nanoparticles: A DFT study

The interaction between Supported Ionic Liquids Phases (SILPs) based on triazole and copper nanoparticles was investigated using density functional theory calculations. Three triazolium cations (T1+, T2+, and T3+) and four anions (I−, BF4−, PF6−, and NTf2−) were considered to form the Cu@SILP complexes. It is shown that the anion adsorption onto copper nanoparticles is favored compared to the cation adsorption. The Cu@SILP interaction is governed by coordinate covalent bonds, which can be modulated with chemical substitution on the triazole ring in the position of N1 and N3, including electron-rich groups. However, the stronger adsorption is observed for Cu@(I)SILP1 complex, which presents the more electron-rich triazole and the higher adsorption value of SILP onto Cu surface (5.18 eV). The surface modification allows us to change the properties of the complexes, where tuning properties using different anions generates a coarse change, while fine-tune can be achieved through chemical modification of a triazolium ring.

Incorporating self-anchored phosphotungstic acid@triazole-functionalized covalent organic framework into sulfonated poly(ether ether ketone) for enhanced proton conductivity

The design of new types of proton-conductive materials with high proton conductivity has sparked tremendous interest. Covalent organic framework (COF), a new category of porous crystalline materials possessing well-defined porosity and tunable functionality, holds great potential as next-generation proton conductors. Here, triazole COF loaded with phosphotungstic acid (HPW@COF) has been incorporated into sulfonated poly(ether ether ketone) (SPEEK) matrix to fabricate SPEEK/HPW@COF composite membranes. The one-dimensional channels of COF lined with protonated triazole (triazolium cations) by hydroscopic HPW and neutral triazole as well as counter anions (PO40W123−) could act as proton-donors and -acceptors forming interconnected hydrogen-bonding networks, thus greatly facilitating proton conduction via Grotthuss-type mechanism particularly under low RH. Accordingly, SPEEK/HPW@COF displayed 35.5 times higher proton conductivity than the plain SPEEK at 65 °C, 40% RH. Moreover, the proton conductivity of SPEEK/HPW@COF remained constant during soaking in water for 15 days, indicating the excellent immobilization of HPW due to the electrostatic interaction between basic nitrogen sites and HPW as well as the confinement effect of microporous COF channels. These results demonstrated that N-heterocycles functionalized COFs gave great promise as effective hosts to encapsulate proton carriers.

Anion-cation synergistic metal-free catalytic oxidative homocoupling of benzylamines by triazolium iodide salts.

Triazolium iodide salts are excellent catalysts for the selective oxidative coupling of benzylamines to yield imines. This metal-free reaction proceeds in quantitative spectroscopic yields when run in refluxing 1,2-dichlorobenzene and open to the air. No catalytic activity was observed with related triazolium tetrafluoroborate salts. Variation of catalyst and reaction atmosphere provides mechanistic insights, and revealed dioxygen as the terminal oxidant and the iodine/iodide couple as key redox component in the catalytic dehydrogenation pathway. While molecular iodine is competent as a catalyst in its own right, the triazolium cation triples the reaction rate and reaches turnover frequencies up to 30 h-1, presumably through beneficial interactions of the electron-poor azolium π system and I2, which facilitate the electron transfer from the substrate to iodine and concomitant formation of I-. This acceleration is specific for triazolium cations and represents a hybrid anion/cation catalytic process as a simple and straightforward route towards imine products, with economic advantages over previously reported metal-based catalytic systems.

First time investigation of the substitution effect at anion part of the ILs on their physicochemical properties using [DMT][4-XPhSO3] (X=NH2, OH, H, F, Br, CHO, CF3, CN and NO2) as a model ILs: A systematic DFT study

Abstract In this study, a different class of high nitrogen content ionic liquids were designed. The physicochemical properties of [DMT][4-XPhSO3], (X = NH2, OH, H, F, Br, CHO, CF3, CN and NO2) IPs based on the triazolium cation and substituted benzene sulfonate anions were fully investigated using M06–2X functional in conjunction with the aug-ccpvdz basis set. For all of the designed ILs the structural parameters, interaction energy between constructing parts, enthalpy of formation, natural charges and topological properties were calculated and discussed. The effect of the substituent change at anion part on the interaction energy and physicochemical properties is taking into account for the first time. As revealed from the results, the strength of the interaction between constructing ionic parts had a linear correlation with the electron content of the anionic part in a way that the more stable ion pairs with higher interaction energies constructed as the electron content of the anionic part increased. Melting point, critical-point temperature, electrochemical stability and conductivity which are some of the important IL,s characteristic physical properties were estimated, compared with each other and discussed with the help of the quantum chemical computationally obtained thermochemical data for nine designed various X substituted [DMT][4-XPhSO3] ILs. Finally, the enthalpy and Gibbs free energy of the formation for nine various substituted anions were calculated.

Assembly of Tetrazolylfuroxan Organic Salts: Multipurpose Green Energetic Materials with High Enthalpies of Formation and Excellent Detonation Performance.

A series of highly energetic organic salts comprising a tetrazolylfuroxan anion, explosophoric azido or azo functionalities, and nitrogen-rich cations were synthesized by simple, efficient, and scalable chemical routes. These energetic materials were fully characterized by IR and multinuclear NMR (1 H, 13 C, 14 N, 15 N) spectroscopy, elemental analysis, and differential scanning calorimetry (DSC). Additionally, the structure of an energetic salt consisting of an azidotetrazolylfuroxan anion and a 3,6,7-triamino-7H-[1,2,4]triazolo[4,3-b][1,2,4]triazolium cation was confirmed by single-crystal X-ray diffraction. The synthesized compounds exhibit good experimental densities (1.57-1.71 g cm-3 ), very high enthalpies of formation (818-1363 kJ mol-1 ), and, as a result, excellent detonation performance (detonation velocities 7.54-8.26 kms-1 and detonation pressures 23.4-29.3 GPa). Most of the synthesized energetic salts have moderate sensitivity toward impact and friction, which makes them promising candidates for a variety of energetic applications. At the same time, three compounds have impact sensitivity on the primary explosives level (1.5-2.7 J). These results along with high detonation parameters and high nitrogen contents (66.0-70.2 %) indicate that these three compounds may serve as potential environmentally friendly alternatives to lead-based primary explosives.

Developing effective electronic-only coupled-cluster and Møller-Plesset perturbation theories for the muonic molecules.

Recently we have proposed an effective Hartree-Fock (EHF) theory for the electrons of the muonic molecules that is formally equivalent to the HF theory within the context of the nuclear-electronic orbital theory [Phys. Chem. Chem. Phys., 2018, 20, 4466]. In the present report we extend the muon-specific effective electronic structure theory beyond the EHF level by introducing the effective second order Møller-Plesset perturbation theory (EMP2) and the effective coupled-cluster theory at single and double excitation levels (ECCSD) as well as an improved version including perturbative triple excitations (ECCSD(T)). These theories incorporate electron-electron correlation into the effective paradigm and through their computational implementation, a diverse set of small muonic species is considered as a benchmark at these post-EHF levels. A comparative computational study on this set demonstrates that the muonic bond length is in general non-negligibly longer than corresponding hydrogenic analogs. Next, the developed post-EHF theories are applied for the muoniated N-heterocyclic carbene/silylene/germylene and the muoniated triazolium cation revealing the relative stability of the sticking sites of the muon in each species. The computational results, in line with previously reported experimental data demonstrate that the muon generally prefers to attach to the divalent atom with carbeneic nature. A detailed comparison of these muonic adducts with the corresponding hydrogenic adducts reveals subtle differences that have already been overlooked.

Experimental and Computational Gas Phase Acidities of Conjugate Acids of Triazolylidene Carbenes: Rationalizing Subtle Electronic Effects.

In recent years, triazolylidene carbenes have come to the forefront as important organocatalysts for a wide range of reactions. The fundamental properties of these species, however, remain largely unknown. Herein, the gas phase acidities have been measured and calculated for a series of triazolium cations (the conjugate acids of the triazolylidene carbenes) that have not been heretofore examined in vacuo. The results are discussed in the context of these species as catalysts. We find correlations between the gas phase acidity and selectivity in two Umpolung reactions catalyzed by these species; such correlations are the first of their kind. We are able to use these linear correlations to improve reaction enantioselectivity. These results establish the possibility of using these thermochemical properties to predict reactivity in related transformations.

Crystal structure, vibrational spectra and DFT studies of hydrogen bonded 1,2,4–triazolium hydrogenselenate

The new hydrogen bonded molecular complex 1,2,4–triazolium hydrogenselenate (THS) is prepared by the reaction of 1H–1,2,4–triazole and selenic acid. This complex is stabilised by N–H⋯O and C–H⋯O hydrogen bonding and electrostatic attractive forces between 1H and 1,2,4–triazolium cations and hydrogen selenate anions. The XRD studies revealed that intermolecular proton transfer occur from selenic acid to 1H–1,2,4–triazole molecule, results in the formation of 1,2,4–triazolium hydrogenselenate which contains 1,2,4–triazolium cations and hydrogenselenate anions. The molecular structure of THS crystal has also been optimised by using Density Functional Theory (DFT) using B3LYP/cc–pVTZ and B3LYP/6–311++G** methods in order to find the whole characteristics of the molecular complex. The theoretical structural parameters such as bond length, bond angle and dihedral angle determined by DFT methods are well agreed with the XRD parameters. The atomic charges and thermodynamic properties are also calculated and analysed. The energies of frontier molecular orbitals HOMO, LUMO, HOMO–1, LUMO+1 and LUMO–HUMO energy gap are calculated to understand the kinetic stability and chemical reactivity of the molecular complex. The natural bond orbital analysis (NBO) has been performed in order to study the intramolecular bonding interactions and delocalisation of electrons. These intra molecular charge transfer may induce biological activities such as antimicrobials, antiinflammatory, antifungal etc. The complete vibrational assignments of THS have been performed by using FT–IR and FT–Raman spectra.

Crosslinked 1,2,4-triazolium-type poly(ionic liquid) nanoparticles

In this work we studied covalently crosslinked poly(ionic liquid) nanoparticles synthesized via aqueous dispersion polymerization of 1,2,4-triazolium ionic liquid monomers in the presence of a dication crosslinker. Compared to their non-crosslinked counterparts, the nanoparticles showed improved structural integrity in organic media. Assisted by cryogenic electron microscopy, these nanoparticles were analyzed in detail and found to present vastly diverse shapes and highly ordered inner mesostructures. Upon altering the length of the alkyl substituents on the triazolium cation from dodecyl to tetradecyl and hexadecyl, a shape transformation from elongated “nanoworms” to a mixture of “onion-like” and “wasp-like” nanoparticles was observed. Additionally, the size variation of these colloidal nanoparticles was investigated systematically by polymerizations at different concentrations of monomer, external added salt and crosslinking agent. Finally, the crosslinked poly(ionic liquid) nanoparticles were able to readily disperse multi-walled carbon nanotubes in water and organic media.

Ruthenium-Free Preparation of 1,5-Disubstituted Triazoles by Alkylative Debenzylation of 1,4-Disubstituted Triazoles

A method that cleanly converts the 1,4-disubstituted 1,2,3-triazole products of the copper-catalyzed ‘click’ dipolar cycloaddition reaction of benzyl azide with terminal alkynes into 1,5-disubstituted triazoles is described. Selective N-alkylation of 1,4-disubstituted 1,2,3-triazoles under microwave irradiation is followed by debenzylation of the resulting 1,3,4-trisubstituted triazolium cations by treatment with potassium tert-butoxide.

Computational studies on 1,2,4-Triazolium-based salts as energetic materials

The results of the computational studies performed on 1,2,4-triazolium cation-based salts designed by pairing it with energetic nitro-substituted 5- membered N-heterocyclic anions such as 5-nitrotetrazolate, 3,5-dinitrotriazolate, and 2,4,5 trinitroimidazolate are reported. Condensed phase heats of formation of the designed ionic salts and their thermodynamic and energetic properties have also been calculated. The results show that these salts are potential energetic materials and possess high positive heats of formation. The detonation velocity, D, and detonation pressure, P, have been calculated using the Kamlet-Jacobs equation and found to be 7–8 km/s and 25–29 GPa, respectively. These values fall in the range of the criteria to designate them as high-energy-density materials. Nucleus independent chemical shift (NICS) studies performed on the designed molecules show that these salts are stable in nature. Condensed phase heats of formation of the designed triazolium-based ionic salts and their thermodynamic and energetic properties have been determined using computational methods. The calculated energetic properties indicate that the –NO2 and the –N3 groups are the effective explosophores for enhancing the detonation performance of the substituted triazolium cations.

Crystal structure of tetra-aqua-bis(3,5-di-amino-4H-1,2,4-triazol-1-ium)cobalt(II) bis-[bis-(pyridine-2,6-di-carboxyl-ato)cobaltate(II)] dihydrate.

The asymmetric unit of the title compound, [Co(C2H6N5)2(H2O)4][Co(C7H3NO4)2]2·2H2O, features 1.5 CoII ions (one anionic complex and one half cationic complex) and one water mol­ecule. In the cationic complex, the CoII atom is located on an inversion centre and is coordinated by two triazolium cations and four water mol­ecules, adopting an octa­hedral geometry where the N atoms of the two triazolium cations occupy the axial positions and the O atoms of the four water mol­ecules the equatorial positions. The two triazole ligands are parallel offset (with a distance of 1.38 Å between their planes). In the anionic complex, the CoII ion is six-coordinated by two N and four O atoms of the two pyridine-2,6-di­carboxyl­ate anions, exhibiting a slightly distorted octa­hedral coordination geometry in which the mean plane of the two pyridine-2,6-di­carboxyl­ate anions are almost perpendicular to each other, making a dihedral angle of 85.87 (2)°. In the crystal, mol­ecules are linked into a three-dimensional network via C—H⋯O, C—H⋯N, O—H⋯O and N—H⋯O hydrogen bonds.

Crystal structures of five 1-alkyl-4-aryl-1,2,4-triazol-1-ium halide salts.

The asymmetric units for the salts 4-(4-fluoro-phen-yl)-1-isopropyl-1,2,4-triazol-1-ium iodide, C11H13FN3 (+)·I(-), (1), 1-isopropyl-4-(4-methyl-phen-yl)-1,2,4-triazol-1-ium iodide, C12H16N3 (+)·I(-), (2), 1-isopropyl-4-phenyl-1,2,4-triazol-1-ium iodide, C11H14N3 (+)·I(-), (3), and 1-methyl-4-phenyl-1,2,4-triazol-1-ium iodide, C9H10N3 (+)·I(-), (4), contain one cation and one iodide ion, whereas in 1-benzyl-4-phenyl-1,2,4-triazol-1-ium bromide monohydrate, C15H14N3 (+)·Br(-)·H2O, (5), there is an additional single water mol-ecule. There is a predominant C-H⋯X(halide) inter-action for all salts, resulting in a two-dimensional extended sheet network between the triazolium cation and the halide ions. For salts with para-substitution on the aryl ring, there is an additional π-anion inter-action between a triazolium carbon and iodide displayed by the layers. For salts without the para-substitution on the aryl ring, the π-π inter-actions are between the triazolium and aryl rings. The melting points of these salts agree with the predicted substituent inductive effects.