35203-44-2Relevant articles and documents
On the mesophase formation of 1,3-dialkylimidazolium ionic liquids
Yang, Mei,Mallick, Bert,Mudring, Anja-Verena
, p. 3068 - 3077 (2013)
A series of seven different 1,3-dialkylimidazolium-based ion-pair salts with the same molecular weight and size but different symmetries was synthesized. For all salts, bromide was chosen as the counterion, giving the series ([CnIMCm][Br]), where IM = imidazolium and Cn and Cm are varying N-alkyl substituents with n + m = 13. Thus, the effect of symmetry on the physicochemical properties, such as thermal transitions, densities and viscosities and particularly mesophase formation, is investigated herein. All salts are fully characterized by NMR spectroscopy and mass spectrometry, and their physicochemical properties such as thermal transitions, densities, and viscosities are reported. Single crystal X-ray structure analysis is reported for 1-tridecylimidazolium bromide ([C0IMC13][Br]) and 1-ethyl-3- undecylimidazolium bromide ([C2IMC11][Br]). Salts 1-tridecylimidazolium bromide ([C0IMC13][Br]) and 1-dodecyl-3-methylimidazolium bromide ([C1IMC12][Br]) exhibit thermotropic liquid crystal behavior, confirmed by differential scanning calorimetry, polarized optical microscopy, and small-angle X-ray diffraction to be the SmA mesophase. A structure with interdigitation of alkyl chains is observed for all of [C0IMC13][Br], [C1IMC12][Br], and [C2IMC11][Br], despite the absence of thermotropic liquid crystalline behavior for the latter (and all other isomers with an alkyl chain length less than 12 carbon atoms). This allows us to draw the conclusion that for the liquid crystal phase of an ionic liquid to exist, not only are the calamitic shape and integral length of a molecule important but a minimal alkyl chain length of n = 12 is also required. Therefore, a dodecyl group could be considered as the functional group responsible for liquid crystalline behavior.
In-situ synthesis of mercury(II)-N-heterocyclic carbene complexes by using “oxide route”, structural characterization and their photo-catalytic degradation activity for dyes
Altaf, Muhammad Faisal,Chaudhary, Sidra,Hasnain, Muhammad,Imran, Muhammad,Iqbal, Muhammad Adnan,Latif, Shoomaila
, (2021/12/30)
N-alkylated imidazole derivatives (1a-1b), mono-azolium salts (SL2-SL3) and their symmetrically (SC2) and non-symmetrically (SC3) substituted mercury(II)-N-heterocyclic carbene (Hg(II)-NHC) complexes were synthesized by using “oxide route”. The characterization was done by using physical (i.e., solubility, melting point determination, compound microscopic analysis) and spectral (i.e., UV-Visible spectroscopy, FT-IR spectroscopy, 1H and 13C NMR spectroscopy) methods. Chemical equilibrium between monomeric and dimeric structures of bromide-bridging Hg(II)-NHC complexes was also observed in the presence of solvent. Photo-catalytic degradation rate of two environmentally polluting dyes i.e., methylene blue (MR) and congo red (CR), was investigated by using compound 1 (SC2) and compound 2 (SC3) which demonstrated that the compound 2 had maximum degradation rate in the range of 70–80% as compared to the compound 1 (60–70% ).
Continuous production process of 2, 3, 5-trichloropyridine
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Paragraph 0013-0014, (2021/10/30)
According to a continuous production process of 2, 3, 5-trichloropyridine, a continuous tubular chlorinator is adopted, pyridine is taken as a starting raw material, chlorination reaction is continuously carried out step by step by virtue of a catalyst 1 and a catalyst 2 which are independently researched and developed, and 2, 5-dichloropyridine and 2, 3, 5-trichloropyridine are prepared in sequence. In the preparation process of a catalyst 1 and a catalyst 2, the mass ratio of 1-chloropropane to imidazole to 2-chloroethyl diphenylphosphine to nickel tetracarbonyl is 1.2: 1: 3.7: 2.5, and the mass ratio of 1-chloropropane to imidazole to 2-chloroethyl diphenylphosphine to sodium hexachlororhodate hydrate is 1.2: 1: 3.7: 15. By means of the continuous tubular chlorinator, cheap and easily available pyridine is used as a starting raw material, chlorine atoms are introduced step by step through catalytic chlorination, the atom economy is good, the reaction selectivity is good, the yield of 2, 3, 5-trichloropyridine can be stabilized at 80% or above, the production efficiency is high, the process is easy to control, and the method is environmentally friendly and suitable for industrial production.
N-Functionalised Imidazoles as Stabilisers for Metal Nanoparticles in Catalysis and Anion Binding
Beer, Paul D.,Cookson, James,Serpell, Christopher J.
, p. 683 - 690 (2020/07/03)
Metal nanoparticles (NPs) have physicochemical properties which are distinct from both the bulk and molecular metal species, and provide opportunities in fields such as catalysis and sensing. NPs typically require protection of their surface to impede aggregation, but these coatings can also block access to the surface which would be required to take advantage of their unusual properties. Here, we show that alkyl imidazoles can stabilise Pd, Pt, Au, and Ag NPs, and delineate the limits of their synthesis. These ligands provide an intermediate level of surface protection, for which we demonstrate proof-of-principle in catalysis and anion binding.
