Imidazole Research Articles

Azoles as corrosion inhibitors in alkaline medium for ruthenium chemical mechanical planarization applications:Electrochemical and theoretical analysis

The adsorption performance and inhibition mechanism of azoles; Imidazole (IMD), 1, 2, 4-Triazole (TAZ), and 1, 2, 3-Benzotriazole (BTAH) inhibitors on ruthenium (Ru) at 9 pH, were investigated in this study using electrochemical techniques and density functional theory (DFT) simulations. The electrochemical data demonstrate that the three azole compounds being investigated are mixed type corrosion inhibitors with anodic predominance, and the order of corrosion inhibition efficiency for Ru is BTAH > TAZ > IMD. The azole compounds suppress the metal dissolution reaction rate by adhering on to the Ru surface and nature of adsorption (combined physisorption and chemisorption) is explained via Langmuir adsorption isotherm model. The increase in contact angle on the Ru surface verified the successful adsorption of the three organic inhibitors on the Ru surface. Furthermore, the suppression of corrosion reaction kinetics is validated with field emission scanning electron microscopy (FESEM) images. The results of quantum chemistry calculations indicate that the corrosion inhibition effect of BTAH is superior to that of IMD and TAZ. Further, using molecular dynamics modelling, the reliable configuration of the organic inhibitor molecules on the Ru (001) surface in aqueous medium was investigated and the total adsorption energy was computed.

Mechanism of efficient electroreduction of CO2 to CO at Ag electrode in imidazolium-based ionic liquids/acetonitrile solution

Imidazolium-based ionic liquids (Imim-ILs) have great application potential in catalyzing the electrochemical CO2 reduction reaction (CO2RR). However, the microscopic mechanism by which imidazolium-based cations promote CO2RR remains unclear. In this study, we observe that despite the structural differences between [Bmmim]+ and [Bmim]+, both exhibit high catalytic activity during the electrochemical CO2RR. Electrochemical and in situ spectroscopic analyses, as well as Quantum Theory of Atomic in Molecules (QTAIM), reveal that the pivotal step in the CO2RR mechanism facilitated by [Bmmim]+ and [Bmim]+ involves the formation of [Bmmim]···CO2 or [Bmim]···CO2 complexes via hydrogen bond. These complexes enhance the electrochemical reduction of CO2 or ·CO2- on electrode, facilitating efficient CO production. Specifically, the [Bmmim]···CO2 complex forms at the C4-H position of the imidazole ring, while in the [Bmim]···CO2 complex, it forms at the C2-H position.

Microbes as carbendazim degraders: opportunity and challenge.

Carbendazim (methyl benzimidazol-2-ylcarbamate, CBZ) is a systemic benzimidazole carbamate fungicide and can be used to control a wide range of fungal diseases caused by Ascomycetes, Basidiomycetes and Deuteromycetes. It is widely used in horticulture, forestry, agriculture, preservation and gardening due to its broad spectrum and leads to its accumulation in soil and water environmental systems, which may eventually pose a potential threat to non-target organisms through the ecological chain. Therefore, the removal of carbendazim residues from the environment is an urgent problem. Currently, a number of physical and chemical treatments are effective in degrading carbendazim. As a green and efficient strategy, microbial technology has the potential to degrade carbendazim into non-toxic and environmentally acceptable metabolites, which in turn can dissipate carbendazim from the contaminated environment. To date, a number of carbendazim-degrading microbes have been isolated and reported, including, but not limited to, Bacillus, Pseudomonas, Rhodococcus, Sphingomonas, and Aeromonas. Notably, the common degradation property shared by all strains was their ability to hydrolyze carbendazim to 2-aminobenzimidazole (2-AB). The complete mineralization of the degradation products is mainly dependent on the cleavage of the imidazole and benzene rings. Additionally, the currently reported genes for carbendazim degradation are MheI and CbmA, which are responsible for breaking the ester and amide bonds, respectively. This paper reviews the toxicity, microbial degradation of carbendazim, and bioremediation techniques for carbendazim-contaminated environments. This not only summarizes and enriches the theoretical basis of microbial degradation of carbendazim, but also provides practical guidance for bioremediation of carbendazim-contaminated residues in the environment.

Discovery, Characterization and Engineering of the Free l-Histidine C4-Prenyltransferase.

Prenylation of amino acids is a critical step for synthesizing building blocks of prenylated alkaloid family natural products, where the corresponding prenyltransferase that catalyzes prenylation on free l-histidine (l-His) has not yet been identified. Here, we first discovered and characterized a prenyltransferase FunA from the antifungal agent fungerin pathway that efficiently performs C4-dimethylallylation on l-His. Crystal structure-guided engineering of the prenyl-binding pocket of FunA, a single M181A mutation, successfully converted it into a C4-geranyltransferase. Furthermore, FunA and its variant FunA-M181A show broad substrate promiscuity toward substrates that vary in substituents of the imidazole ring. Our work furthers our knowledge of free amino acid prenyltransferase and expands the arsenal of alkylation biocatalysts for imidazole-containing small molecules.

Structure and intermolecular interactions in ionic liquid 1-ethyl-3-methylimidazolium bromide and its aqueous solutions investigated by vibrational spectroscopy and quantum chemical computations.

The recently developed efficient protocol to explicit quantum mechanical modeling of structure and IR spectra of liquids and solutions (S. A. Katsyuba, S. Spicher, T. P. Gerasimova, S. Grimme, J. Phys. Chem. B 2020, 124, 6664) is applied to ionic liquid (IL) 1-ethyl-3-methylimidazolium bromide (EmimBr), its C2-deuterated analog [Emim-d]Br and its aqueous solutions. It is shown that the solvation strongly modifies frequencies and IR intensities of the CH/CD stretching vibrations (νCH/νCD) of the imidazolium ring. The main vibrational spectroscopic features of the neat IL are reproduced by the simulations for a cluster (EmimBr)9, in which all three imidazolium CH moieties of the solvated cation form short contacts with three Br- anions, and another two Br- anions are located on top and bottom of imidazolium ring. Cluster models of aqueous solutions reproduce the experimental vibrational frequencies of actual solutions, provided that the Br- anion of solvated contact ion pair (CIP) is situated on top of imidazolium ring, and CH/CD moieties of the latter participate in short contacts with surrounding water molecules. Both structural and spectroscopic analysis allow to interpret the short contacts CH/CD⋯Br- and CH/CD⋯OH2 as hydrogen bonds of approximately equal strength. Enthalpies of bonding of these liquid-state H-bonds, estimated with the use of empirical correlations, amount to ca. 1.4 kcal⋅mol-1, while the analogous estimates obtained for the gas-phase charged species [Emim]2Br+ increase to 5.6 kcal⋅mol-1. It is shown that formation of solvent-shared ion pair (SIP) in aqueous solution, where the counterions of IL are separated by two water molecules H-bonded to a Br- anion, produces frequency shifts ΔνCH/CD, strongly different from the case of CIP formation. This difference can be used for IR/Raman spectroscopic differentiation of the type of solvated ion pairs of EmimBr or other related ILs.

Abstraction of Trifluoroborane from Tetrafluoroborate: Li+‐Assisted Borylation of Nucleophilic Carbenes

AbstractThe small, lipophilic tetrafluoroborate anion is ubiquitous in the imidazol(in)ium and iminium precursors to N‐heterocyclic carbenes (NHCs), including cyclic (alkyl)(amino)carbenes (CAACs). Its symmetrical distribution of charge over four highly electronegative fluorine atoms confers high stability, attenuating basicity while shielding the boron center. Here we report that this inertness does not withstand the nucleophilicity of free carbenes, when combined with a polarizing lithium cation. Reaction of CAAC ⋅ HBF4 salts with LiN(SiMe3)2, a protocol widely used to liberate free CAACs, generates zwitterionic CAAC‐BF3 adducts within minutes at 80 °C, or hours at room temperature, even for bulky N‐diisopropylphenyl (DIPP) CAACs. Imidazol(in)ium tetrafluoroborates likewise form NHC‐BF3 adducts in excellent yields.

Noncovalent Interactions and Transverse Vibration Induced Restricted Thermal Expansion of Organic Salts Derived from Imidazole and Carboxylic Acids.

Design of material showing contraction upon heating is highly challenging due to varying mechanism. However, imidazole is found to be a potential molecule that may provide low CTE materials when incorporated in the matrix. Here we have reported thermal expansion property of imidazolium salts of five aliphatic α, ω-alkane dicarboxylic acids and three aromatic acids. Either uniaxial or biaxial negative thermal expansion (NTE) has been observed in most of the salts. In some cases, axial zero thermal expansion (ZTE) has been observed. The role of imidazolium moiety for the anomalous thermal expansion behaviour of the salts has been analyzed in this study. The controlled TE behaviour of the salts is attributed to the hydrogen bonding and transverse vibration in all imidazolium salts. Owing to the high transverse vibration observed in imidazolium ion as well as the heavier oxygen atoms of acids in each case, the distance between hydrogen bonded atoms decreases-which provides either low expansion or contraction along one of the principal axes.

Efficient synthesis of novel 1,10 phenanthroline-substituted imidazolium salts: Exploring their anticancer applications

This study reports a new series of 1,10-phenanthroline-substituted imidazolium salts (1a–f), examining their design, synthesis, structure and anticancer activities. The structures of these salts (1a–f) were characterized using 1H, 13C NMR, elemental analysis, mass spectrometry and Fourier transform infrared (FT-IR) spectroscopies. The salts' cytotoxic activities were tested against cancer cell lines, specifically MCF-7, MDA-MB-231 and non-tumorigenic MCF-10A mammary cells. The study compared the impact of aliphatic and benzylic groups in the salts’ structure on their anticancer activity. Screening results revealed that compound 1c, in particular, showed promising inhibitory activity against the growth of MDA-MB-231 breast cancer cells, with an IC50 value of 12.8 ± 1.2 μM, indicating its potential as a chemotherapeutic agent. Cell apoptosis analysis demonstrated a tendency for compound 1c to induce early apoptosis in breast cancer cells. The stability/aquation of compound 1c was investigated using 1H NMR spectroscopy and its binding modes with DNA were explored via UV–Vis spectroscopy. Additionally, the study investigated the interaction residues and docking scores of compound 1c and the reference drug doxorubicin against Bax and Bcl-2 proteins using molecular docking.

Synergistic activation of peroxymonosulfate by the laminate metals of MgMnFe-layered double hydroxides for imidacloprid degradation

Mg, Mn and Fe as environmental-friendly elements were introduced into the laminates of layered double hydroxides (LDHs) to synthesize MgMnFe-LDHs for peroxymonosulfate (PMS) activation to degrade imidacloprid (IMI). The catalytic activity of MgMnFe-LDHs was influenced by the Mn content in the LDH laminates, and Mg2Mn1Fe with Mn/Mg = 0.5 exhibited superior performance that 250 mg/L of dosage achieving 93.1 % degradation of IMI (10 mg/L) by activating PMS (0.65 mM) within 30 min. The mesoporous structure facilitated the contact between PMS and active sites, the abundant surface hydroxyl groups (–OH) provided sites for PMS complexation, and the synergism of Mn and Fe promoted PMS adsorption and electron transfer ability of Mg2Mn1Fe, thereby accelerating the production of SO4•− and •OH. The primary active sites were identified by density functional theory calculations that H-OI-OII-SO3- is absorbed through the binding of OI site with –OH of Mg2Mn1Fe, and the adsorption is more likely to occur on –OH connected with Mg-Mn-Fe rather than Mg-Mg-Fe and Mg-Mg-Mn. Based on the identification of degradation products, the degradation reaction types of IMI were proposed, including the opening of imidazole ring, carbonylation, denitrification, hydroxylation, dechlorination, and N-dealkylation. This study provides new insights into the design of efficient and environmentally-friendly LDH-based catalysts for PMS activation and the interaction mechanism between PMS and hydroxyl groups in LDH laminates.

Electrosynthesis of Metal–Organic Framework Interlayer to Realize Highly Stable and Kinetics‐Enhanced Zn Metal Anode

AbstractTo facilitate the practical application of aqueous Zn metal batteries, numerous artificial interlayers are designed to mitigate rampant parasitic reactions and uncontrollable dendrite growth on the Zn metal anode. Traditionally, these interlayers are prepared through the doctor blade method. However, the introduced insulting binder generally compromises their interfacial performance. In this study, the metal–organic framework (MOF) interlayer is fabricated on the Zn metal anode by a facile and binder‐free electrosynthesis technique. The electrosynthetic Co‐ZIF‐8 interlayer enables the Zn metal anode to sustain cycles of 1280 h with a low voltage hysteresis. Moreover, the full cells coupled with MnO2 and NH4V4O10 cathodes exhibit exceptional cycling performance, maintaining 89% and 72% of their initial capacity after numerous cycles, respectively. Based on SEM measurements and density functional theory calculations, the densely packed morphology, unimpeded Zn2+ ions transport channels, and affinity of the imidazole ring and Co node within the ZIF‐8 structure to Zn atom are demonstrated to inhibit parasitic reactions, promote Zn2+ ions transport, and realize uniform Zn deposition. The proposed electrosynthesis method for constructing the MOF interlayer provides a straightforward and reliable approach to developing a highly stable Zn metal anode.

Effect of ether chain and isomerism on surface and antimicrobial activity of mono- and dicationic imidazolium-based surface-active ionic liquids

A series of 16 imidazolium-based surface-active ionic liquids (SAILs) were synthesized. The designed SAILs, consisted of either one amphiphilic center, 3-alkoxymethyl-1-benzylimidazolium or 3-alkoxymethyl-1-benzyl-2-methylimidazolium, and two amphiphilic centers, 3,3′-[α,ω-(dioxaalkane)]bis(1-benzylimidazolium) or 3,3′-[α,ω-(dioxaalkane)]bis(1-benzyl-2-methylimidazolium). These compounds were investigated in terms of thermal analysis, ability to self-organize to micelles, and antimicrobial activity. The insertion of an ether moiety in the alkyl side or spacer chain favored adsorption at the air–water interface and micellization in the bulk solution when compared to commercial chloride surfactants. The results showed that attachment of a methyl group to the imidazolium ring led to lower the critical micelle concentration (CMC) than lengthening the alkyl chain or spacer in the imidazolium cation. Additionally, biological activity increased with increasing hydrophobicity of the compounds. The methylation of the imidazole ring at positions 2 and 2′ yielded in a notable increase in bacteriostatic activity, especially against Gram-positive bacteria, notably the Staphylococcus aureus strains. It has been demonstrated that minor structural modifications, specifically substituting the imidazole ring instead of elongating the alkyl chain or spacer, can modify the micellization and aggregation behavior, leading to differences in both the efficacy and variety of antimicrobial activity of amphiphilic SAILs.

Single Point Mutation Abolishes Water Capture in Germacradien-4-ol Synthase.

The high-fidelity sesquiterpene cyclase (-)-germacradien-4-ol synthase (GdolS) converts farnesyl diphosphate into the macrocyclic alcohol (-)-germacradien-4-ol. Site-directed mutagenesis was used to decipher the role of key residues in the water control mechanism. Replacement of Ala176, located in the G1/2 helix, with non-polar aliphatic residues of increasing size (valine, leucine, isoleucine and methionine) resulted in the accumulation of the non-hydroxylated products germacrene A and germacrene D. In contrast, hydroxylation was maintained when the polar residues threonine, glutamine or aspartate replaced Ala176. Additionally, although a contribution of His150 to the nucleophilic water addition could be ruled out, the imidazole ring of His150 appears to assist carbocation stabilisation. The results presented here shed light on how hydroxylating sesquiterpene synthases can be engineered to design modified sesquiterpene synthases to reduce the need for further steps in the biocatalytic production of oxygenated sesquiterpenoids.

Electrochemical, microstructural and theoretical validation of 2-(2-Bromophenyl)-1H-benzimidazole as inhibitor for C1018 steel during very aggressive CO2 corrosion

This work is motivated by the lack of research papers reporting benzimidazole derivatives in very aggressive CO2-corrosion systems. We appraise the inhibitive performance of 2-(2-bromophenyl)-1 H Benzimidazole (BPHB) in CO2-saturated 3.5 % sodium chloride (NaCl) + 50 ppm acetic acid (HAc) without and with 1 M hydrochloric acid (HCl) using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), scanning electron microscopy (SEM) and x-ray diffraction (XRD). We augment results from these techniques with molecular dynamics simulations and density functional theory, as computational modelling techniques. In the absence of HCl, the inhibitor adsorbs firmly on the steel surface, displays a strong cathodic influence on corrosion potential (Ecorr) and current density (icorr), and minimizes both general and pitting corrosion with ∼ 80 % efficiency. The presence of HCl furnishes abundant H+ ions that significantly diminish the cathodic influence of BPHB, blocks its firm adsorption and, although it reduces the extent of general and pitting corrosion, lowers its efficiency to ∼ 70 %. Computational modelling techniques confirm electrochemical and surface probe results. The nitrogen atoms and CC bonds in the imidazole ring are the centers that facilitate BPHB adsorption. The inhibitor adsorbs in such a way as to maximize surface coverage. However, adsorption is more energetically favored in the absence of HCl, based on Eads calculations.

In situ carbon nanonetwork structure based on MOF-derived carbon to manufacture ceramic composites: A case study of zirconia-toughened alumina

Highly robust ceramics materials are promising materials for applications in the automobile, aerospace, and ceramic cutting tool industries. However, conventional ceramics are typically brittle, which limits their suitability for advanced applications. In this study, with zeolite imidazolium salt skeleton-8 (ZIF-8) as a carbon source, discharge plasma sintering is used to create carbon nanonetworks derived from metal-organic frameworks (MOFs) in situ on the grain boundaries of zirconia-toughened alumina (ZTA) ceramic. ZTA exhibits maximum bending strength (719 ± 20.5 MPa) and fracture toughness (7.91 ± 0.7 MPa m1/2) at MOF concentrations of 1.0 wt% and 2.0 wt%, respectively, which are 1.37 and 1.88 times higher than that of the unmodified sample. This demonstrates that the MOF-derived carbon nanonetworks significantly improve the mechanical properties of the ceramic. The finite element analysis results indicate that the carbon nanonetworks can effectively disperse the stress inside the material and transfer the concentrated stress from the internal defects to the two-phase grain boundary on the surface of the sample, thereby contributing to strengthening and toughening. Overall, this work validates that the in situ production of carbon nanonetworks from MOFs is an effective strategy to enhance the mechanical properties of ZTA ceramics. Moreover, it offers new approaches for reinforcing and toughening other ceramic materials.

A novel comb-shaped polybenzimidazoles crosslinked sulfonic acid functionalized polyphosphazenes high temperature proton exchange membrane

Designing high temperature proton exchange membranes (HTPEMs) with high H+ conductivity and long durability has been challenging. Here, a comb-shaped polybenzimidazoles (CbPBI) and crosslinkable polyoxy (benzenesulfonic acid) phazenes (PBSP) proton conductors are prepared, then they are used to fabricate a series of PBSP-CbPBI membranes with good comprehensive performances. CbPBI provides high flexibility and large free volume, which facilitates the construction of proton transport channels. And PBSP is the bifunctional proton conductor and crosslinker that introduces abundant sulfonic acid groups while retaining the crosslinkable property. By strongly chemical binding with CbPBI, the basicity of the imidazole ring is enhanced, avoiding the leaching of PBSP, thus enabling the overall crosslinked membrane to exhibit a durable intrinsic proton conductivity. Benefiting from the construction of the dual crosslinked network (covalent and ionic crosslinking), the oxidative stability, dimensional stability, and fuel-blocking properties of the PBSP-CbPBI membranes perform well. The proton conductivity of PBSP(50)-CbPBI membrane reaches 0.163, 0.084, 0.057, and 0.043 S/cm, respectively, at 180 °C and different relative humidity (100 % RH, 50 % RH, 30 % RH, and 0 RH). Enduring hot-washing for 96 h, the less decay of membrane in conductivity and weight demonstrates good durability. The design strategy such as the construction of monolithic crosslinked macromolecular structures in PBSP-CbPBI membranes shows wide application prospects in HTPEMs.

Hydrolytic opening of the imidazole ring under action of acetylenecarboxylic acid derivatives

Hydrolytic opening of the imidazole ring under action of acetylenecarboxylic acid derivatives

Long-term exposure to ionic liquid [C8mim]Br induces the potential risk of anxiety and memory deterioration through disturbing neurotransmitter systems

1-octyl-3-methylimidazolium bromide ([C8mim]Br), one of the ionic liquids (ILs), has been used in various fields as an alternative green solvent of conventional organic solvents. Increased application and stabilization of imidazole ring structure lead to its release into the aquatic environment and long-term retention. Structure-activity relationship consideration suggested that ILs may be acetylcholinesterase inhibitors; however, neurotoxicity in vivo, especially the underlying mechanisms is rarely studied. In this study, the zebrafish were exposed to 2.5–10 mg/L [C8mim]Br for 28 days to comprehensively evaluate the neurotoxicity of ILs on adult zebrafish from the behavioral profiles and neurotransmitter systems for the first time. The results indicate that zebrafish exhibit suppressed spatial working memory and anxious behaviors. To assess the potential neurotoxic mechanisms underlying the behavioral responses of zebrafish, we measured the levels of neurotransmitters and precursors, key enzyme activities, and expression levels of relevant genes. Nissl staining showed significant neural cell death in zebrafish after 28-day [C8mim]Br exposure, with corresponding decreases in the levels of neurotransmitters (acetylcholine, glutamate, 5-hydroxytryptophan, gamma-aminobutyric acid, dopamine, and norepinephrine). Furthermore, these results were associated with mRNA expression levels of the disrupted neurotransmitter key genes (th, tph2, mao, slc6a3, ache, gad67). Overall, our study determined that [C8mim]Br caused potential mental disorders like anxiety and memory deterioration in zebrafish by impairing neurotransmitter systems, providing recommendations for the industrial production and application of [C8mim]Br.

Steroidal 21-imidazolium salt derivatives: Synthesis and anticancer activity

Nitrogen-containing steroids are known as prostate cancer therapeutics. In this work, a series of pregnane derivatives bearing an imidazolium moiety were synthesized using Δ16-20-ketones as starting material. An improved approach for the construction of the 20-keto-21-heterocycle-substituted fragment involved the rearrangement of 16,17-epoxides with HCl, followed by reaction of the formed α-chloroketone with 1-substituted imidazoles. Binding affinity analysis of the imidazolium steroids and their synthetic intermediates to human CYP17A1 showed only type I (substrate-like) interactions. The strongest affinity was observed for 16α,17α-epoxy-5α-pregnan-20-on-3β-ol (Kd = 0.66 ± 0.05 µM). The steroid derivatives have been evaluated for antitumor activity against a range of prostate cancer cells as well as against various other solid tumor and hematologic cancer cell lines. All 21-imidazolium salts were active against the hormone-dependent prostate cancer line LNCaP. The most pronounced cytotoxicity in solid tumor and hematologic cancer cell lines was observed for intermediate product, 21-chloro-5α-pregn-16-en-20-on-3β-ol. Among the imidazolium salts, the derivatives with a single bond were more cytotoxic than their unsaturated congeners.

An unusual CAr^CNHC- and bidentate NAr^CNHC-cyclometalated Re(I)-NHC complexes with quinoline-functionalized ligands: Syntheses, structures, and blue-luminescent properties

An unusual CAr^CNHC-cyclometalated rhenium(I) tetracarbonyl complexes fac- (CAr^CNHC)Re(CO)4 (13) (the first report) and six NAr^CNHC-cyclometalated rhenium(I) tricarbonyl iodide/chloride complexes with quinoline-functionalized N-heterocyclic carbenes (NHC), fac-Re(CO)3(LNHC)I / fac-Re(CO)3(LNHC)Cl (LNHC = 1-(quinolin-8-yl)-3-methyl-1H-imidazol-2-ylidene (4, 10); 1-(quinolin-8-yl)-4-methyl-1H-1,2,4-triazoline-5-ylidene (5, 11); 1-(quinolin-8-yl)-3-benzyl-1H-imidazol-2-ylidene (6, 12) have been synthesized under controllable reaction conditions and characterized by their 1H NMR, 13C NMR, ESI–MS, IR spectra, and single-crystal X-ray diffraction analysis. X-ray crystallography revealed that the Re(I)-NHC complex 13 is a rare five-member bidentate CAr^CNHC-cyclometalated structure containing the coplanar system of quinoline and imidazole ring with a dihedral angle of 7.6°. The density functional theory (DFT) calculations also indicated that the blue shift of 50 nm for the MLCT absorption band of 13 is in good agreement with the coplanar five-member cyclometalated structure and the Re(I)-NHC complex 10 is a thermodynamic product. Seven Re(I)-NHC complexes exhibit photoluminescence emission in the blue region (410–470 nm) with relatively short decay lifetime on the nanosecond time scale, and high quantum yields of the Re(I)-NHC complexes 5 (Φ = 0.558) and 6 (Φ = 0.629) based-triazole were calculated by using [Ru(bpy)3](PF6)2 in degassed acetonitrile solution (Φstd = 0.062) as standard, due to the coordination of quinoline rings, NHC ligands to Re(I) center.

Imidazole-based hydrazones as potent anti-colon cancer agents: Design, synthesis, biological evaluation and computational studies

Compounds containing imidazole and hydrazone structural frameworks have been widely studied and demonstrated to exhibit a wide range of pharmacological properties. In this study, a descriptive series of 20 new hybrid compounds composed of an imidazole ring and a hydrazone moiety were designed and synthesized through multistep chemical reactions. Synthesized compounds were characterized by various spectral techniques, including FT-IR, 1H NMR, 13C NMR and HRMS. Furthermore, the proposed structure of AB-1 was resolved by single-crystal X-ray analysis. The compounds were evaluated for their in vitro anti-colon cancer activity, and the most promising compounds (i.e., AB-6, AB-9, AB-11 and AB-18) exhibited significant dose- and time-dependent cytotoxicity with selectivity to HT-29 and HCT-116 cells. In addition, Molecular docking, molecular dynamics simulations, and binding free energy analyses were carried out to better understand the structure-activity relationships and mechanisms of action of the potential anticancer agents. Our preliminary findings suggest that compounds AB-6, AB-9, AB-11, and AB-18 could be exploited as a leading structure for further anticancer drug development.