23996-53-4Relevant articles and documents
Structures and single crystal to single crystal transformations of cadmium frameworks using a flexible tripodal ligand
Zhang, Zongyao,Xu, Lijin,Cao, Rui
, p. 5593 - 5601 (2018)
A highly flexible tris-imidazole ligand N(CH2-m-C6H4-CH2-imidazole)3 (L) constructed using a tris(xylyl) backbone was synthesized. Its reactions with three cadmium(ii) salts gave various Cd(ii) coordination polymers, namely [CdL2](ClO4)2 (1), [CdLCl2] (2), and [CdL(OAc)2] (3). X-ray studies revealed that 1 crystallized in the trigonal space group R3 with high symmetry, while 2 and 3 crystallized in lower symmetrical space groups due to Cd-anion coordination. The flexibility of ligand L was evidenced in these structures, showing different conformations of L upon coordination and crystallization. In addition, complex [CdL2]Cl2 (4) was obtained by the anion exchange of 1 with sodium chloride via a single crystal to single crystal transformation. Similar to 1, complex 4 also crystallized in the trigonal space group R3 with a = 13.0945(3), b = 37.4353(10), and V = 5559.2(2). Importantly, this single crystal to single crystal transformation is crucial to afford this Cd(ii) coordination polymer with unbound Cl- anions, as the direct reaction of L and CdCl2 gives complex 2 with Cd-bound Cl-. This work shows the importance of flexible ligands in constructing various coordination polymer structures through the regulation of anions.
Physicochemical and thermodynamic properties of imidazolium ionic liquids with nitrile and ether dual functional groups
Raj, Jaganathan Joshua,Wilfred, Cecilia Devi,Shah, Syed Nasir,Pranesh, Matheswaran,Abdul Mutalib,Lethesh, Kallidanthiyil Chellappan
, p. 281 - 289 (2017)
Synthesis of new dual functionalized imidazolium ionic liquids (ILs) containing nitrile functionality and ether group were synthesized and characterized. Bis(trifluoromethylsulfonyl)imide, trifluoroacetate and dicyanamide were used as the anion. The combination of two functional groups on an imidazolium cation was mainly developed to assess their potential in desulfurization of fuel oil. Although ILs based on this individual functional group has been reported to improve the desulfurization efficiency, no effort has been made to combine nitrile and ether functional groups on the same cation to enhance the desulphurization potential. In this report, we tailored both nitrile and ether functionality on imidazolium cation and studied their physicochemical properties in details. NMR (1H and 13C) spectroscopy and elemental analysis were used to characterize the synthesized ILs. Physical properties and optical properties of the ILs were investigated in a wide temperature range. The synthesized ILs showed good thermal stability. COSMO-RS was effectively utilized to discuss the σ surface, σ potential and σ profile of the synthesized ILs.
Thermophysical properties of a new dicationic ionic liquid
Claros, Martha,Galleguillos, Hector R.,Brito, Ivan,Graber, Teofilo A.
, p. 2147 - 2152 (2012)
A new functionalized dicationic ionic liquid was synthesized with the final aim of studying its application in the extraction of metal ions in the mineral industry. In light of this application, the density, refractive index, and dynamic viscosities have been determined and correlated as a function of temperature. Density data were used to calculate the volumetric properties of the ionic liquid. Several empirical equations were used to evaluate the correlation between the density and refractive indices. The results show that the modified Eykman equation has the best fit. In addition, thermal behavior was measured by thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), and a high thermal stability and a wide liquid phase range were determined.
Thermophysical properties of 1-propyronitrile-3-alkylimidazolium bromide ionic liquids at temperatures from (293.15 to 353.15) K
Ziyada, Abobakr K.,Wilfred, Cecilia D.,Bustam, M. Azmi,Man, Zakaria,Murugesan, Thanapalan
, p. 3886 - 3890 (2010)
In the present work, a series of 1-propyronitrile-3-alkylimidazolium bromide ionic liquids ([C2CN Cnim]Br, where n = 4, 6, 8, and 10) were synthesized and characterized using Fourier transform infrared spectroscopy (FTIR), NMR, and elemental analysis. Physical properties such as density, viscosity, and refractive index are measured and reported for a temperature range of (293.15 to 353.15) K and at atmospheric pressure. The influence of the alkyl chain on these properties is discussed. The present synthesized ionic liquids show a weak temperature dependency on the thermal expansion coefficient.
-
Yamada,Fujimoto
, p. 557 (1971)
-
One-pot solvent-free microwave-assisted aza-Michael addition reaction of acrylonitrile
Das, Parineeta,Devi, Nirmala,Puzari, Amrit
, (2022/03/23)
A novel and highly effective one-pot microwave-assisted aza-Michael addition reaction of acrylonitrile, as Michael acceptor with various primary aliphatic and aromatic amines, as Michael donor has been reported. The reaction was catalyzed by a cost-effective, highly efficient and eco-friendly catalyst, molecular sieve of 4 A0 size, under solvent-free conditions. A detail investigation on reaction controlling parameters like reaction timing and amount of catalyst was studied. The plausible mechanistic pathway has been proposed for the formation of acrylonitrile adducts. The identity of the synthesized products was established by conventional spectroscopic techniques FT-IR, 1H and 13C{1H} NMR, ESI-MS and DLS measurements. DLS result shows hydrodynamic diameter of lower alkyl chain in the range of 200–300 nm and for higher alkyl chain around 1 μm. Sheldon's hot filtration test confirms the significance of the catalyst and their heterogeneity was also confirmed by recycling it for five consecutive cycles without any noticeable change in the yield.
Solvent- and Catalyst-Free Aza-Michael Addition of Imidazoles and Related Heterocycles
Gobec, Florian,Kodolitsch, Katharina,Slugovc, Christian
, (2020/05/18)
This work demonstrates the scope and limitations of the aza-Michael addition of imidazoles and related heterocycles with electron deficient olefins under solvent- and catalyst-free conditions. The reaction proceeds at 80 °C within hours towards completion as long as the azole derivative is sufficiently soluble in the Michael acceptor, which has been used in small excess. Workup only comprises evaporation of surplus Michael-acceptor, and no additional solvents are necessary for purifying the products.
Efficient protocol for Aza-Michael addition of N-heterocycles to α,β-unsaturated compound using [Ch]OH and [n-butyl urotropinium]OH as basic ionic liquids in aqueous/solvent free conditions
Kumar, Sitanshu,Kaur, Amanpreet,Singh, Vasundhara
, p. 193 - 201 (2019/01/24)
The present work emphasizes on a green methodology using designed and synthesized basic ionic liquid, [n-butyl Urotropinium]OH, and commercially available aqueous solution of choline hydroxide [Ch]OH as catalysts for executing Aza-Michael addition of N-heterocycles to α,β-unsaturated compounds at room temperature. The highlighting features of these catalysts include using low concentration of both catalysts along with [Ch]OH being low cost and biodegradable, [n-butyl Urotropinium]OH significantly enhancing the high substrate/catalyst ratio to obtain the desired products in high yield and purity in most cases. Further, both catalysts were recyclable and recoverable up to five cycles.