Pyrazolium based Ionic Liquids: Crystal Structures and Theoretical Calculations

2018-04-27
Özdemir, Melek
Şahin, Ertan
Ionic liquids (IL) are ionic, salt-like materials and composed of an organic cation and anion. Different types of anions and cations can be used to modify the chemical and physical properties of the IL. Phosphonium, ammonium, sulfonium, imidazolium, picolinium, pyridinium, pyrrolidinium, thiazolium, oxazolium and pyrazolium cations are widely used cations in the synthesis of ionic liquids, while hexafluorophosphate and tetrafluoroborate are the most prominent anions used in IL synthesis [1]. A series of tunable aryl alkyl ionic liquids (TAAILs) based on 1-aryl-3,5-dimethyl-1H-pyrazoles were synthesized and characterized by Özdemir and Özgün [2]. The crystal structures of two of these ionic salts 1-(4-bromophenyl)- 2,3,5- trimethylpyrazolium tetrafluoroborate (I) and 1-(4-bromophenyl)-2,3,5- trimethylpyrazolium hexafluorophosphate (II) were obtained by X-ray diffraction techniques. The optimized molecular geometries (Figure 1) and 1H/13C NMR chemical shift values were obtained using Gaussian 09 package program. The DFT/B3LYP method together with basis set 6-311+G(d,p) was used to study the molecular structures of ILs. Their 1H NMR and 13C NMR chemical shift values were compared with the calculated results obtained by B3LYP/6- 311G++(2d,2p) in the solvent CDCl3 by applying GIAO approach. It was observed that the calculated geometrical parameters are very compatible with X-ray diffraction results.

Suggestions

1-Aryl-3,5-dimethylpyrazolium based tunable protic ionic liquids (TPILs)
Özdemir, Melek; AKTAN, EBRU (2019-03-15)
A series of new 1-aryl-3,5-dimethylpyrazolium based tunable protic ionic liquids/salts ([Ph(R)Hpz][X], R: -H, -Cl, -Br, -CH3, -OCH3, X: chloride [Cl-] and tetrafluoroborate (BF4-) have been synthesized through acid-base neutralization reactions between 1-aryl-3,5-dimethy1-1H-pyrazoles and the corresponding inorganic acids. The chemical structure of the salts was confirmed by FTIR, H-1 NMR, C-13 NMR, elemental analysis, and F-19 NMR (3a-3e) and the crystal structure of the two salts (2a and 3d) was also eluc...
Enantioselective direct aldol reactions promoted by phosphine oxide aziridinyl phosphonate organocatalysts
Doğan, Özdemir (2015-12-15)
A series of phosphine oxide based chiral Lewis bases were screened as organocatalysts for silicon tetrachloride mediated direct asymmetric aldol reactions between cyclohexanone and various aromatic aldehydes. One of the phosphine oxide-aziridinyl phosphonate POAP-A Lewis bases formed the aldol products in up to 75% yield and with 65% ee.
Effects of para-substitution and alkyl chain length on the melting points of tunable aryl alkyl pyrazolium hexafluorophosphate ionic liquids
Özdemir, Melek (null; 2018-04-27)
Ionic liquids (ILs) are low-melting organic salts that consist entirely of ions. During the last decade, they have found numerous applications because of their unique properties such as wide liquid range, nonflammability and negligible vapor pressure at ambient temperatures [1-3]. The properties of ILs can be tuned by changing the constituent ions. In recent years, unlike commonly known alkyl substituted ILs a new class of ILs called Tunable Aryl Alkyl Ionic Liquids (TAAILs) has drawn attention [4-6]. By re...
Phenyl/alkyl-substituted-3,5-dimethylpyrazolium ionic liquids
Özdemir, Melek (2014-12-01)
The synthesis and characterization of a series of new phenyl/alkyl-substituted-3,5-dimethylpyrazolium ionic liquids ([Phpz(R)][X] R = CnH2n+1 n: 1,2,3,4,5,6,7 [X] = CH3SO3-, BF4-, PF6-) are described. Their melting points, thermal stabilities, electrochemical windows, and solubility properties in common solvents were investigated. They were found to exhibit very good electrochemical and thermal stabilities. The results indicate that these ionic liquids have a high thermal stability up to 374 degrees C and a...
Covalent immobilization of chloroperoxidase onto magnetic beads: Catalytic properties and stability
Bayramoglu, Guelay; Kiralp, Senem; Yilmaz, Meltem; Toppare, Levent Kamil; Arica, M. Yakup (Elsevier BV, 2008-02-15)
Amino groups containing magnetic beads were used in covalent immobilization of the enzyme "chloroperoxidase (CPO)" which is one of a few enzymes that can catalyse the peroxide dependent oxidation of a wide spectrum of organic and inorganic compounds. The magnetic poly(glycidylmethacrylate-methylmethacrylate-etbyleneglycol dimethacrylate), magnetic p(GMA-MMA-EGDMA) beads were prepared via suspension polymerization in the presence of ferric ions. The magnetic beads were characterized with scanning electron mi...
Citation Formats
M. Özdemir and E. Şahin, “Pyrazolium based Ionic Liquids: Crystal Structures and Theoretical Calculations,” 2018, Accessed: 00, 2021. [Online]. Available: https://www.eurasianbiochem.org/bildiri20taslaklarC4B1/Abstract_Book_EurasianBioChem_2018.pdf.