2525-19-1

Usage

Type of compound

Quaternary ammonium salt

Constituents

Pyridinium cation and iodide anion

Common use

Phase-transfer catalyst

Function as a catalyst

Enables reactions between immiscible phases (e.g., aqueous and organic solvents)

Application in organic synthesis

Reagent for various transformations

Specific reactions in organic synthesis

N-alkylation and N-oxidation reactions

Potential application

Antimicrobial agent

Additional studies

Pharmaceutical and industrial use

Upstream product

• 152119-73-8 6-methylbenzo<1,5>naphthyridine 
• 74-88-4 methyl iodide 
• 108-48-5 2,6-dimethylpyridine 

Downstream Products

• 106547-87-9 2,6-bis-(4-diethylamino-trans-styryl)-1-methyl-pyridinium; iodide 
• 148738-51-6 2-(4-dimethylamino-trans-styryl)-1,6-dimethyl-pyridinium; iodide 
• 139557-70-3 2,6-bis<(4-dimethylaminophenyl)iminomethyl>-1-methylpyridinium iodide 
• 6832-21-9 2,6-di(isopropyl)pyridine 
• 5402-34-6 2-isopropyl-6-t-butylpyridine 
• 585-48-8 2,6-di-tert-butyl-pyridine 
• 74701-47-6 2-ethyl-6-isopropyl pyridine 
• 3785-05-5 2,6-bis(4-dimethylaminostyryl)-1-methylpyridinium iodide 

Relevant academic research and scientific papers

Synthesis, absorption and fluorescence spectral characteristics of trinucleus dimethine cyanine dyes as fluorescent probes for DNA detection

The preparation of six trinucleus dimethine cyanine dyes with pyridine nucleus obtained by the condensation of trimethylpyridinium iodides with heterocyclic aromatic aldehyde was described. The absorption and fluorescence properties of the dyes were studied in different polarity solvents. Blue shift of the maxima absorption of the dyes was observed with the increase of solvents polarity. The fluorescence properties of the dyes in solution and in presence of DNA were studied. Significant enhancement of the fluorescent quantum yield was observed in four dyes in the presence of DNA. Specially, one of six dyes emitted weak fluorescence in Tris-HCl buffer, but displayed bright fluorescence in the presence of DNA.

Loop-mediated fluorescent probes for selective discrimination of parallel and antiparallel G-Quadruplexes

Herein we report simple pyridinium (1–3) and quinolinium (4) salts for the selective recognition of G-quadruplexes (G4s). Among them, the probe 1, interestingly, selectively discriminated parallel (c-KIT-1, c-KIT-2, c-MYC) G4s from anti-parallel/hybrid (22AG, HRAS-1, BOM-17, TBA) G4s at pH 7.2, through a switch on response in the far-red window. Significant changes in the absorption (broad 575 nm → sharp 505 nm) and emission of probe 1 at 620 nm, attributed to selective interaction with parallel G4s, resulted in complete disaggregation-induced monomer emission. Symmetrical push/pull molecular confinements across the styryl units in probe 1 enhanced the intramolecular charge transfer (ICT) by restricting the free rotation of C[dbnd]C units in the presence of sterically less hindered and highly accessible G4 surface/bottom tetrads in the parallel G4s, which is relatively lower extent in antiparallel/hybrid G4s. We confirm that the disaggregation of probe 1 was very effective in the presence of parallel G4–forming ODNs, due to the presence of highly available free surface area, resulting in additional π-stacking interactions. The selective sensing capabilities of probe 1 were analyzed using UV–Vis spectroscopy, fluorescence spectroscopy, molecular dynamics (MD)–based simulation studies, and 1H NMR spectroscopy. This study should afford insights for the future design of selective compounds targeting parallel G4s.

Multi-styrene substituted pyridine compound as G- tetramer nucleic acid fluorescent probe (by machine translation)

The probe can be used for detecting G - quadruplex structures. in a solution through a fluorescence spectrophotometer, and the probe can be used for detecting a (I) quadruplex structure, in a nucleic acid, quadruplex structure, and has good cell membrane

A study on a telo21 G-quadruplex DNA specific binding ligand: Enhancing the molecular recognition ability: Via the amino group interactions

A symmetric ligand is synthesized composed of a core N-methylpyridinium scaffold and two para-substituted benzyl groups through a flexible ethylene bridge to form a novel three-ring-conjugated system. The ligand system was found to have only weak background fluorescent signal in aqueous or physiological conditions and exhibited strong fluorescent signal enhancement targeting at telo21 G-quadruplex structure rather than other types of nucleic acids. The comparison study with two terminal groups (-N(CH3)2versus -SCH3) indicates that the stimulated signal enhancement of specific binding is probably attributed to the hydrogen-bonding interactions through the amino groups in the G-quartets. The docking result illuminates the experimental observation that the ligand system showed only weak fluorescent signals in aqueous or physiological conditions while exhibiting a strong fluorescent signal upon binding to the telo21 G-quadruplex structure (binding energy: -6.2 kcal mol-1).

Efficient synthesis of aluminosilicate RTH zeolite with good catalytic performances in NH3-SCR and MTO reactions

2,6-methyl-N-methylpyridinium, as a novel organic template, is employed for the synthesis of RTH aluminosilicate zeolite with a SiO2/Al2O3 ratio of 17.6. The amount of 2,6-methyl-N-methylpyridinium template, the Na2O/SiO2 ratio, the SiO2/Al2O3 ratio, and the H2O/SiO2 ratio in the starting gel significantly influence the crystallization of RTH zeolite. Several analytical methods such as XRD, SEM, N2 sorption, TG-DTA, DRIFT and NMR were employed for the characterisation of the obtained RTH zeolites and to understand the crystallization process with the new template. Very interestingly, the crystallization of RTH zeolite with the new template takes a very short time (12 h at 130 °C and 50 min at 240 °C) compared with conventional RTH zeolite synthesis reported in the literature (72 h at 130 °C). Theoretical calculations show that this novel organic template has lower interaction energies for zeolite cage space filling than those of the organic templates previously reported in the literature, which lead to stronger structural directing. Kinetic results show that the activation energy of this novel organic template is much lower than that of the traditional one. Catalytic tests show that copper exchanged RTH zeolite (Cu-RTH) exhibits good catalytic properties in the NH3-SCR reaction and the H-RTH zeolite catalyst has excellent selectivities for ethylene and propylene in MTO reactions.

Biomolecular recognition at the cellular level: Geometrical and chemical functionality dependence of a low phototoxic cationic probe for DNA imaging

A combined approach was adopted to understand the impact of structural geometry as well as suitable chemical functionality of a molecular probe on its efficient binding in the minor groove of DNA. The development of a small chemical library of different lutidinium conjugates (P1-P5) and molecular simulations using DFT calculations clearly demonstrated that the semilunar conformation of a molecular probe equipped with requisite chemical functionality is the key parameter for its proper binding in the minor groove of DNA. The comparative optical responses of these probes (P1-P5) coupled with the theoretical studies illustrated that only P3 displayed considerable fluorescence enhancement in the presence of DNA because of its semilunar geometry and special chemical architecture. Furthermore, the bioassays clearly revealed that the probe can penetrate the cell membrane of live as well as dead cells without the help of any permeabilization agent. Microscopic cellular imaging established that probe P3 can stain the nuclear region of the cells with high contrast and negligible cytoplasmic spillage without causing any cellular deterioration. The specificity and binding efficiency of P3 toward DNA were established by performing DNase/RNase digest tests and gel electrophoresis experiments. Most importantly, P3 exhibited minimum phototoxicity and high photobleaching resistance in cellular medium under continuous exposure to a light source, which are highly desirable for real time monitoring of many biological events. Altogether, the investigated properties of P3 shed light on its admirable and persuasive standing as a cell-compatible, bright and photostable molecular probe for nuclear imaging in various bio-medical applications.

Solvatochromism of symmetrical 2,6-distyrylpyridines. An experimental and theoretical study

Seven symmetrical 2,6-distyrylpyridines, phenyl-substituted with hydrogen-bond donors, hydrogen-bond acceptors, halogens and hydrophobic moieties were synthesized and their spectroscopic characterization was done. Solvent effects on the absorption and fluorescence spectra were analyzed and quantified using the Kamlet-Taft and Catalán approach. The obtained results were rationalized by comparison of electrostatic potentials of the molecules in the ground and in excited state and by comparison of the frontier molecular orbitals (HOMO and LUMO), derived from quantum-mechanical calculations (HF, DFT, MP2). Analysis of the results revealed an important influence of non-specific (dispersive) interactions on the solvatochromic behavior of the compounds. 1D and 2D NMR data, in silico obtained conformational assembly of the compound, and the NMR analysis of molecular flexibility in solution (NAMFIS), were used to estimate population of conformers and to deconvolute the UV-Vis spectrum of representative derivative; inferring that the conformational assembly is more complex than was assumed in so far published literature data for this class of compounds. Along with this, the emission spectra of the representative compounds were decomposed by the Multivariate Curve Resolution analysis.

Synthesis of pyridine acrylates and acrylamides and their corresponding pyridinium ions as versatile cross-linkers for tunable hydrogels

A small library of cross-linkers for hydrogels was synthesized. The cross-linkers consisted of 2,6- and 3,5-diacylpyridine or 2,4,6-triacylpyridine as the core unit, which were tethered via ethylene glycol, amino ethanol, and 1,n-diamine spacers to terminal acrylate or acrylamide moieties. Esterification and amide formation of the terminal acryl units were found to be dependent on the ratio of NH/O in the spacer, the constitution pattern of the pyridine ring, and the total number of acryl groups. Thus, esters generally gave higher yields than amides decreasing with increasing number of NH in the spacer and with increasing number of acryl units. In the case of 3,5-diacylpyridine derivatives, these trends were less prominent as compared to the 2,6-diacylpyridine series, indicating that steric hindrance and unfavorable hydrogen bonding interaction of the spacers might influence the observed reactivity differences. The 3,5-diacylpyridines were converted to the N-methylpyridinium salts and selected members of both neutral and cationic 3,5-diacylpyridinium derivatives were submitted to hydrogelations with synthetic polymer poly(1-glycidylpiperazine) via aza-Michael addition and thiolated natural hyaluronan via thio-Michael reaction, respectively. Rheological properties of the resulting hydrogels were studied, revealing that both spacer type as well as charge affected elastic moduli and degree of swelling. Georg Thieme Verlag Stuttgart New York.

Synthesis and nonlinear optical absorption properties of two new conjugated ferrocene-bridge-pyridinium compounds

Two electron donor-π-acceptor (D-π-A) chromospheres, with ferrocene as the electron donor and pyridinium as the electron acceptor, were synthesized. The nonlinear optical absorption (NOA) properties in the solution state were investigated by the Z-scan technique. Both compounds exhibited reverse saturable absorption (RSA) and optical limiting effect under nanosecond pulse irradiation.

Combinatorial approach to organelle-targeted fluorescent library based on the styryl scaffold

The first fluorescent styryl dye library with a broad color range was synthesized by combinatorial condensation of various aldehydes and methyl pyridinium compounds, and their applications as organelle specific staining probes were demonstrated. Copyright