18994-77-9Relevant articles and documents
Molecular assemblies from imidazolyl-containing haloalkenes and haloalkynes: Competition between halogen and hydrogen bonding
Bouchmella, Karim,Boury, Bruno,Dutremez, Sylvain G.,Van Der Lee, Arie
, p. 6130 - 6138 (2007)
The structural characterization of molecular assemblies constructed from imidazolyl-containing haloalkenes and haloalkynes is reported. 1-(3-Iodopropargyl)imidazole (2) and 1-(2,3,3-triiodoallyl)imidazole (5) were synthesized from 1-propargylimidazole (1). In the solid state, these wholly organic modules self-assemble through N...I halogen-bonding interactions, thus giving rise to polymeric chains. The N...I interaction observed in 2 (d(N...I) = 2.717 A, spherical angle sign C(sp)-I...N = 175.8°) is quite strong relative to previously reported data. The N...I interaction in 5 (d(N...I) = 2.901 A, spherical angle signC(sp 2)-I...N = 173.6°) is weaker, in accordance with the order C(sp)-X←base>C(sp2)-X←base. Compound 5 was found to give a 1:1 cocrystal 4 with morpholinium iodide (6). In the X-ray crystal studies of 4, N...I halogen-bonding interactions similar to those observed in 5 were shown not to be present, as the arrangement of the molecules is governed by two interwoven hydrogenbonding networks. The first network involves N-H...O interactions between nearby morpholinium cations, and the second network is based on N-H...N hydrogen bonding between morpholinium cations and imidazolyl groups. Both hydrogen-bonding schemes are charge-assisted. Halogen bonding is not completely wiped out, however, as the triiodoalkene fragment forms a halogen bond with an iodide anion in its vicinity (d(I...I) = 3.470 A, spherical angle signC(sp2)-I...I = 170.7°). X-ray crystal studies of 6 show a completely different arrangement from that observed in 4, namely, N-H...O interactions are not present. In crystalline 6, morpholinium cations are interconnected through C-H...O bridges (d(H...O)=2.521 and 2.676 A), and the NH2+ groups interact with nearby iodide anions (d(H...I)=2.633 and 2.698 A).
Balancing Physicochemical Properties of Phenylthiazole Compounds with Antibacterial Potency by Modifying the Lipophilic Side Chain
Abdel-Aleem, Jelan A.,Abutaleb, Nader S.,Ali, Alsagher O.,Elsebaei, Mohamed M.,Kotb, Ahmed,Mancy, Ahmed,Mayhoub, Abdelrahman S.,Mohammad, Haroon,Saad, Abdullah Y.,Seleem, Mohamed N.
, (2019)
Bacterial resistance to antibiotics is presently one of the most pressing healthcare challenges and necessitates the discovery of new antibacterials with unique chemical scaffolds. However, the determination of the optimal balance between structural requirements for pharmacological action and pharmacokinetic properties of novel antibacterial compounds is a significant challenge in drug development. The incorporation of lipophilic moieties within a compound's core structure can enhance biological activity but have a deleterious effect on drug-like properties. In this Article, the lipophilicity of alkynylphenylthiazoles, previously identified as novel antibacterial agents, was reduced by introducing cyclic amines to the lipophilic side chain. In this regard, substitution with methylpiperidine (compounds 14-16) and thiomorpholine (compound 19) substituents significantly enhanced the aqueous solubility profile of the new compounds more than 150-fold compared to the first-generation lead compound 1b. Consequently, the pharmacokinetic profile of compound 15 was significantly enhanced with a notable improvement in both half-life and the time the compound's plasma concentration remained above its minimum inhibitory concentration (MIC) against methicillin-resistant Staphylococcus aureus (MRSA). In addition, compounds 14-16 and 19 were found to exert a bactericidal mode of action against MRSA and were not susceptible to resistance formation after 14 serial passages. Moreover, these compounds (at 2× MIC) were superior to the antibiotic vancomycin in the disruption of the mature MRSA biofilm. The modifications to the alkynylphenylthiazoles reported herein successfully improved the pharmacokinetic profile of this new series while maintaining the compounds' biological activity against MRSA.
Anion recognition by halogen bonding and hydrogen bonding bis(triazole)-imidazolium [2]rotaxanes
Turner, Grace,Docker, Andrew,Beer, Paul D.
, p. 12800 - 12805 (2021)
A novel halogen bonding (XB) bis(iodotriazole)-imidazolium motif is incorporated into the axle component of a [2]rotaxane via a discrete chloride anion template directed clipping methodology. 1H NMR anion titration experiments reveal the interlocked host
Ionic conductor with high conductivity as single-component electrolyte for efficient solid-state dye-sensitized solar cells
Wang, Hong,Li, Juan,Gong, Feng,Zhou, Gang,Wang, Zhong-Sheng
, p. 12627 - 12633 (2013)
Imidazolium iodide is an often used component in iodine-based dye-sensitized solar cells (DSSCs), but it cannot operate an efficient DSSC in the absence of iodine due to its low conductivity. For this study, lamellar solid iodide salts of imidazolium or piperidinium with an N-substituted propargyl group have been prepared and applied in solid-state DSSCs. Owing to the high conductivity arising from the lamellar structure, these solid-state ionic conductors can be used as single-component solid electrolytes to operate solid-state DSSCs efficiently without any additives in the electrolyte and post-treatments on the dye-loaded TiO2 films. With a propargyl group attached to the imidazolium ring, the conductivity is enhanced by about 4 × 104-fold as compared to the alkyl-substituted imidazolium iodide. Solid-state DSSC with the 1-propargyl-3-methylimidazolium iodide as the single-component solid-state electrolyte has achieved a light-to-electricity power conversion efficiency of 6.3% under illumination of simulated AM1.5G solar light (100 mW cm-2), which also exhibits good long-term stability under continuous 1 sun soaking for 1500 h. This finding paves the way for development of high-conductivity single-component solid electrolytes for use in efficient solid-state DSSCs.
Effects of repeat unit charge density on the physical and electrochemical properties of novel heterocationic poly(ionic liquid)s
Cotessat, Merlin,Flachard, Dimitri,Nosov, Daniil,Lozinskaya, Elena I.,Ponkratov, Denis O.,Schmidt, Daniel F.,Drockenmuller, Eric,Shaplov, Alexander S.
, p. 53 - 65 (2021)
We report the synthesis and structure/property correlations of a series of eight poly(ionic liquid)s (PILs) obtained from sequential AA + BB polyaddition by copper(i)-catalyzed azide-alkyne cycloaddition and the subsequent N-alkylation reaction. The different repeat units contain one to four ion pairs, with one to four bis(trifluorosulfonyl)imide (TFSI) anions and one or two types of ammonium, imidazolium or 1,2,3-triazolium counter-cations. Their physical, ion conducting and electrochemical properties are discussed based on the repeat unit charge density and structure of the cationic moieties. The comparison of several pairs of polyelectrolytes revealed that ionic conductivity is dependent on (1) the ratio between the number of charge carriers per monomer unit and the number of surrounding atoms/groups that can solvate the ions and (2) the nature of the cation. The highest conductivity (1.8 × 10-5 S cm-1 at 25 °C) was reached when PILs contain two 1,2,3-triazolium cations that are separated by an oxyethylene spacer. The incorporation of an additional type of cation (either imidazolium or ammonium with 1,2,3-triazolium) in one PIL allows its cathodic limit to be increased up to -0.4 V vs. Li+/Li (70 °C) and the oxidation instability of 1,2,3-triazolium cations to be overcome.
Anti-migration of Nitrogen-rich N-Heterocyclic Ferrocenes and Their Combustion Catalytic Properties in the Thermal Decomposition of Energetic Oxidizers
Shi, Xiaoling,Yang, Lufei,Jiang, Liping,Bi, Fuqiang,Zhang, Guofang
, (2021/12/14)
To retard high migration tendency of alkylferrocene-based burning rate catalysts and ameliorate their combustion catalytic activity, twenty new nitrogen-rich N-heterocyclic ferrocenyl compounds 1–20 were synthesized by click reaction and characterized by NMR, UV-Vis, FT-IR, ESI-MS, etc. Six compounds were structurally confirmed by single crystal X-ray diffraction additionally. TG studies showed that the new ferrocenyl compounds are highly thermal stable. Cyclic voltammetry results implied that some new ferrocenyl compounds exhibit reversible electrochemical behavior, which are favorable for their combustion catalytic performance in the composite solid propellants. The anti-migration tests confirmed that the new ferrocenyl compounds exhibit neglectable migration trends after four-week aging on comparison with ferrocene and catocene. The catalytic combustion tests of AP, RDX and HMX over the compounds 1–20 indicated that these N-heterocyclic ferrocenes are all highly active for improving thermal degradation of AP and RDX and more active than the aniline-derived counterparts prepared by click reaction.
Ferrocene burning rate catalyst containing bis (imidazole or pyrazole-1, 2, 3-triazole) group and preparation method thereof
-
Paragraph 0023-0026, (2021/05/12)
The invention discloses a ferrocene burning rate catalyst containing a bis (imidazole or pyrazole-1, 2, 3-triazole) group and a preparation method thereof, the structural formula of the burning rate catalyst is shown in the specification, R1 and R2 independently represent-C or-N, R represents-H or-NO2, and R1 and R2 are different. According to the invention, more nitrogen atoms are introduced into the ferrocene burning rate catalyst, so that hydrogen bonds are easily formed in molecules, and the compounds are not easy to migrate and volatilize under natural conditions and have good thermal stability. As the nitrogen-rich group has high formation heat and combustion heat, the ferrocene burning rate catalyst can improve the energy level of a solid propellant when being used in the solid propellant, and has a good combustion catalysis effect on main components, namely ammonium perchlorate and hexogen, of the solid propellant. Theburning rate catalyst is synthesized by adopting a click reaction method, the preparation method is simple to operate and low in synthesis cost, and the defects of complex synthesis process, high price, high cost and the like of the existing ferrocene and derivatives thereof are overcome.
Ferrocenyl -1 , 2, 3 - triazole group-containing imidazole and pyrazole burning rate catalyst and preparation method thereof
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Paragraph 0021-0024, (2021/12/01)
The invention discloses a ferrocene methyl -1 , 2, 3 - triazole group-containing imidazole and pyrazole burning rate catalyst and a preparation method thereof. In-flight R1 . R2 A respective independent representation - C or - N, R represents - H or - NO. 2 , And R1 , R2 . By introducing more nitrogen atoms into the ferrocene-based burn-up catalyst, hydrogen bonds are easily formed in the molecules, so that the compounds are difficult to migrate and volatilize under natural conditions, and the thermal stability is good. Because the nitrogen-rich group has higher heat generation and combustion heat, the energy level of the solid propellant can be improved in the solid propellant, and the solid propellant main component has better combustion catalysis effect on ammonium perchlorate and black cable gold. The preparation method is simple to operate and low in synthesis cost, and overcomes the defects of complex synthesis process, high price, high cost and the like of the existing ferrocene and derivatives thereof.
Palladium(II) Complexes of a Neutral CCC-Tris(N-heterocyclic carbene) Pincer Ligand: Synthesis and Catalytic Applications
Angeles-Beltrán, Deyanira,Mendoza-Espinosa, Daniel,Rendón-Nava, David,Rheingold, Arnold L.
, p. 2166 - 2177 (2021/07/20)
Treatment of tris-azolium precursor 1 with palladium acetate under thermal conditions provided a CCC-pincer palladium(II) complex (2) bearing three NHCs (one imidazolylidene and two triazolylidenes) and one iodide ligand. Further treatment of complex 2 with an excess of AgSbF6 generates tris(carbene) dicationic palladium complex 3 in which the iodine ligands are exchanged with SbF6 anions and the metal center is stabilized by one acetonitrile ligand. Complexes 2 and 3 were tested in several cross coupling reactions showing high conversions under low catalyst loadings and mild reaction conditions. Additionally, complexes 2 and 3 performed well in the hydrosilylation of terminal alkynes with good selectivity toward the E-isomer.
Design and characterization of a heterocyclic electrophilic fragment library for the discovery of cysteine-targeted covalent inhibitors
Keeley,ábrányi-Balogh,Keseru
supporting information, p. 263 - 267 (2019/03/05)
A fragment library of electrophilic small heterocycles was characterized through cysteine-reactivity and aqueous stability tests that suggested their potential as covalent warheads. The analysis of theoretical and experimental descriptors revealed correlations between the electronic properties of the heterocyclic cores and their reactivity against GSH that are helpful in identifying suitable fragments for cysteines with specific nucleophilicity. The most important advantage of these fragments is that they show only minimal structural differences from non-electrophilic counterparts. Therefore, they could be used effectively in the design of targeted covalent inhibitors with minimal influence on key non-covalent interactions.
