16836-76-3

Upstream product

• 19497-20-2 N₁,N₁,N₃,N₃-tetramethylguanidinium 
• 64-19-7 acetic acid 
• 80-70-6 N,N,N',N'-tetramethylguanidine 

Relevant academic research and scientific papers

Vaporization of protic ionic liquids studied by matrix-isolation fourier transform infrared spectroscopy

Several protic ionic liquids (PILs) with a wide range of pKa differences (ΔpKa) between the parent acid and base molecules were thermally evaporated in vacuum, trapped on a CsI plate by a cryogenic neon matrix-isolation method, and studied by Fourier transform infrared spectroscopy and density functional theory calculations. The parent neutral molecules and proton-transferred cation-anion pair species were identified as chemical components evaporated from the PILs with lower and higher ΔpKa values, respectively. The ΔpKa-dependent vaporization mechanism is discussed in terms of thermodynamic equilibrium between acid-base and anion-cation systems in the liquid phase.

Distillable acid-base conjugate ionic liquids for cellulose dissolution and processing

Heating up: Improved recyclability is necessary for ionic liquids destined for wood-based bioprocessing platforms. New "distillable" molten acid-base conjugates efficiently dissolve cellulose at temperatures of 100 °C. Increased temperature induces a shift of the acid-base equilibrium toward the neutral species (see picture, TMG=1,1,3,3-tetramethylguanidine), thus affording a vapor pressure and allowing for distillation of the mixture. Copyright

Diazobicyclo[5.4.0]undec-7ene-ium and tetramethyl guanidium based ionic liquids enhanced thermal stability of xylose reductase at extreme pH through specific ion effect

As part of sustainable industrial bioprocesses, conversion of xylose from lignocellulosic biomass residues has gained attention and importance over recent decades. Xylitol is one such imperative metabolites which can be obtained in a single step conversion from xylose through enzymatic process employing xylose reductase. Xylose reductase from Debaryomyces nepalensis NCYC 3413 (DnXR) has proved to be potential candidate for this purpose due to its industrially superior characteristics compared to the enzymes from other sources. Ionic liquids have applications in various fields, especially in biotechnology, as a replacement of organic solvents as well as for efficient processes and improvement of existing process by enhancing the stability of biomolecules. In this study, effect of diazobicyclo[5.4.0]undec-7ene-ium (DBU), tetramethyl guanidium (TMG) based and Cholinium based ionic liquids on the activity and stability of DnXR was investigated in terms of thermodynamic parameters, half-life time as well as the intrinsic tryptophan fluorescence at pH 5.0, 7.0 and 10.0. [TMG][But] and [DBU][Acetate] were effective in improving the enzyme activity at pH 10.0 by 72% and 58%. [TMG][Acetate] increased the functional stability at pH 10.0 by 10-fold while maintaining the activity same as control and [DBU][Chloride] enhanced the half-life time by 8.5-fold at pH 5.0.

Understanding the efficiency of ionic liquids-DMSO as solvents for carbohydrates: use of solvatochromic- And related physicochemical properties

The physical dissolution of carbohydrates (cellulose, chitin, and starch),i.e., without the formation of covalent bonds requires the solvent to possess certain physicochemical properties. Concentrating on cellulose, the solvent should act both as a Lewis acid and a Lewis base, and disrupt the present hydrophobic interactions, as the biopolymer exhibits amphiphilic characteristics. The quantification of the relative importance of these physicochemical properties helps in predicting the solvent structures, which are expected to be efficient as cellulose solvents. Ionic liquids (ILs) are extensively used as carbohydrate solvents because they disrupt the intramolecular-, intermolecular-, and hydrophobic interactions within the biopolymer structure, leading to its dissolution. Solvatochromic substances (probes) are especially sensitive to one or more of the above-mentioned biopolymer-solvent interactions. Consequently, they are used to predict and rationalize the solvent efficiency. The solvent parameters (descriptors) most widely employed are empirical polarity,ET(probe), Lewis acidity (SA); Lewis basicity (SB), dipolarity (SD), and polarizability (SP); S refers to the solvent. We synthesized 18 ILs, including derivatives of imidazole, 1,8-diazabicyclo[5.4.0]undec-7-ene, and tetramethylguanidine; the corresponding anions are carboxylates, chloride and dimethylphosphate. We used solvatochromic probes to calculate the descriptors of IL-DMSO (at fixed DMSO mole fraction of 0.6; 40 °C), and correlatedET(probe) with the other descriptors. We also tested the correlations by using a molar volume of the IL (VM) instead of SD, and the Lorentz-Lorenz refractive index functionf(n) of the IL-DMSO mixture instead of SP. The quality of the regression analysis increased noticeably when we limited the ILs correlated with those based on imidazole (13 ILs), and used (VM) andf(n). The regression coefficients showed that SA is the most important descriptor; the solvent empirical polarity is inversely dependent onVM. The value off(n) shows the importance of hydrophobic interactions. By using different probes, we showed that the observed small contribution of SB reflects the steric crowding around the positive nitrogen atoms in some probes. The results obtained help in selecting ILs as solvents for cellulose and other carbohydrates, based on the expected strength of their interactions with the biopolymers. Therefore, using solvatochromism for solvent efficiency screening saves labor and cost.

Ionic liquid assisted silver-catalyzed one-pot A3-coupling reactions for the synthesis of propargylamines

A series of ionic liquids with different cations and anions were synthesized and their performances for the silver catalyzed one-pot A3-coupling reactions were investigated. The selection showed that the combination of AgNO3 and ioni

An integrated high-throughput strategy enables the discovery of multifunctional ionic liquids for sustainable chemical processes

Development of new chemical processes with simplified reaction systems and work-up procedures is a challenging task. Although ionic liquids are a class of potential multifunctional compounds to simplify traditional chemical processes, their rational design is difficult due to complex interactions. In this work, a proof-of-concept strategy has been proposed to achieve an integration of high-throughput preparation of ionic liquids and in situ screening of their reaction-promoting performance in 96-well plates. The integrated approach then enables a facile identification of optimal ionic liquids from a 400-ionic liquid candidate pool to act as the solvent, the catalyst and the separating assistant, simultaneously, for carbonyl-azide cycloaddition reactions. Merits of the ionic liquids-based processes have been demonstrated not only in the convenient and efficient synthesis of 1,2,3-triazolyl compounds but also in the discovery of a new reaction for the chemical post-modification of free peptides.

Superbase ionic liquids for effective cellulose processing from dissolution to carbonisation

A range of superbase derived ionic liquids (SILs) was synthesised and characterised. Their ability to dissolve cellulose and the characteristics of the produced fibres were correlated to their specific structural and solvent properties. 17 ionic liquids (ILs) (including 9 novel) were analysed and six ILs were selected to produce fibres: 1-ethyl-3-methylimidazolium acetate [C2C1im][OAc], 1-ethyl-3-methylimidazolium diethyl phosphate [C2C1im][DEP] and the SILs 1-ethyl-1,8-diazabicyclo[5.4.0]undec-7-enium diethylphosphate [DBUEt][DEP], 1,8-diazabicyclo[5.4.0]undec-7-enium acetate [DBUH][OAc], 1,5-diazabicyclo[4.3.0]non-5-enium acetate [DBNH][OAc] and 1-ethyl-1,5-diazabicyclo[4.3.0]non-5-enium diethylphsophate [DBNEt][DEP]. The mechanical properties of these fibres were investigated. The obtained fibres were then carbonised to explore possible application as carbon fibre precursors. The fibres obtained using a mixture of 1,5-diazabicyclo[4.3.0]non-5-enium based SILs with acetate and hexanoate anions (9 : 1), [DBNH][OAc][Hex], showed a promising combination of strength, stiffness and strain at failure values for applications in textiles and fibre reinforcement in renewable composites. Using Raman spectroscopy it is demonstrated that these fibres exhibit a relatively high degree of structural order, with fewer defects than the other materials. On the other hand, analogous fibres based on imidazolium cation with acetate and hexanoate anions (9 : 1), [C2C1im][OAc][Hex] showed a decline in the quality of the produced fibres compared to the fibres produced from [C2C1im][OAc], [C2C1im][DEP] or [DBNH][OAc][Hex].

Fast and efficient extraction of DNA from meat and meat derived products using aqueous ionic liquid buffer systems

A short, simple and inexpensive process for the extraction of DNA from meat was developed investigating a set of 20 ionic liquids including imidazolium, choline and guanidinium derivatives in combination with aqueous buffer systems. The environmentally benign ionic liquid choline hexanoate-phosphate buffer mixture gave the most promising results and DNA was extracted within 20 minutes from different types of meats, such as beef, chicken, pork and horse in significantly higher yields compared to the pure phosphate buffer. The influence of the ionic liquid on the amplification process during the PCR was further investigated, showing an inhibitory effect with increasing chain length of the ionic liquid and with higher ionic liquid concentrations. Additionally, extracted DNA was stable for 20 days when stored at room temperature in aqueous ionic liquid-buffer mixtures.

Facile one-pot synthesis of flavanones using tetramethylguanidinum-based ionic liquids as catalysts

Several tetramethylguanidinum-based ionic liquids (TMGILs) were prepared, characterized and used as catalysts in one-pot synthesis of flavanones. The results indicated that TMGILs composed of phenolate anion was beneficial for one-pot synthesis of flavanones, and [TMG][4-MeO-PhO] induced the good yields of flavanones owing to the electron-donating effect of methoxy substituent on phenolate anion. Furthermore, [TMG][4-MeO-PhO] was found to be used repetitively at least five times without obvious decrease in activity and quantity.

Protic ionic liquid [TMG][Ac] as an efficient, homogeneous and recyclable catalyst for one-pot four-component synthesis of 2H-indazolo[2,1-b]phthalazine- triones and dihydro-1H-pyrano[2,3-c]pyrazol-6-ones

The mildly basic ionic liquid N,N,N,N-tetramethylguanidinium acetate [TMG][Ac] was found to be a very effective basic catalyst for the one-pot, four-component synthesis of 2H-indazolo[2,1-b]phthalazine-triones by condensation of phthalic anhydride, hydrazinium hydroxide, aromatic aldehydes, and dimedone in high yields at 80 °C. [TMG][Ac] catalyzed simple and efficient one-pot four-component reaction of Meldrums acid, ethyl acetoacetate, hydrazine hydrate, and aromatic aldehydes to give dihydro-1H-pyrano[2,3-c] pyrazol-6-ones is reported. The ionic liquid could be recycled several times without loss of efficiency with regards to the reaction times and yields.