Novel Chemical Route to Size-Controlled Ta(0) and Ru-Ta Nanoparticles in Ionic Liquids

2012 ◽  
Vol 1473 ◽  
Author(s):  
Inga S. Helgadottir ◽  
Philippe P. Arquillière ◽  
Paul S. Campbell ◽  
Catherine C. Santini ◽  
P.-H. Haumesser

ABSTRACTMetallic nanoparticles under 10 nm are of particular interest for the microelectronics industry. However, there is a lack of convenient synthetic routes to control their size Oxophilic metals, such as Ta, are also of high interest, however, the high oxophilicity and melting point makes the synthesis of such nanoparticles challenging. Making use of imidazolium-based ionic liquids, monodisperse zero-valent tantalum nanoparticles (Ta(0)NPs) have been successfully synthesised at room temperature by reduction of tris(neopentyl)neopentylidenetantalum(V). Furthermore; well size-controlled bimetallic Ru-Ta NPs have also been synthesized.

2019 ◽  
Author(s):  
Teresa Naranjo ◽  
Rubén Álvarez-Asencio ◽  
Patricia Pedraz ◽  
Belén Nieto-Ortega ◽  
Enrique Burzurí ◽  
...  

Hydrogen bonds are arguably the most important of noncovalent interactions. The physical properties of water and the information storage in DNA depend on H-bonding, for instance. To this day, the balance between the Coulombic and covalent contributions to H-bonds is still under debate. Here, we show that H-bonded host-guest systems associate in ionic liquids, pure salts with melting point below room temperature, in which dipole-dipole electrostatic interactions should be negligible in comparison with dipole-charge interactions. Binding constants (<i>K</i><sub>a</sub>) obtained from titrations of four H-bonded host-guest systems in two organic solvents and two ionic liquids yield smaller yet comparable <i>K</i><sub>a</sub>values in ionic liquids than in organic solvents. We also detect the association event using force spectroscopy. Our results indicate that strong H-bonds are only moderately affected by surroundings composed entirely of charges, suggesting that the balance of Coulombic to covalent forces is not tipped towards the former.


2019 ◽  
Author(s):  
Teresa Naranjo ◽  
Rubén Álvarez-Asencio ◽  
Patricia Pedraz ◽  
Belén Nieto-Ortega ◽  
Enrique Burzurí ◽  
...  

Hydrogen bonds are arguably the most important of noncovalent interactions. The physical properties of water and the information storage in DNA depend on H-bonding, for instance. To this day, the balance between the Coulombic and covalent contributions to H-bonds is still under debate. Here, we show that H-bonded host-guest systems associate in ionic liquids, pure salts with melting point below room temperature, in which dipole-dipole electrostatic interactions should be negligible in comparison with dipole-charge interactions. Binding constants (<i>K</i><sub>a</sub>) obtained from titrations of four H-bonded host-guest systems in two organic solvents and two ionic liquids yield smaller yet comparable <i>K</i><sub>a</sub>values in ionic liquids than in organic solvents. We also detect the association event using force spectroscopy. Our results indicate that strong H-bonds are only moderately affected by surroundings composed entirely of charges, suggesting that the balance of Coulombic to covalent forces is not tipped towards the former.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Teresa Naranjo ◽  
Rubén Álvarez-Asencio ◽  
Patricia Pedraz ◽  
Belén Nieto-Ortega ◽  
Sara Moreno-Da Silva ◽  
...  

Abstract We show that H-bonded host–guest systems associate in ionic liquids (ILs), pure salts with melting point below room temperature, in which dipole–dipole electrostatic interactions should be negligible in comparison with dipole-charge interactions. Binding constants (Ka) obtained from titrations of four H-bonded host–guest systems in two organic solvents and two ionic liquids yield smaller yet comparable Ka values in ionic liquids than in organic solvents. We also detect the association event using force spectroscopy, which confirms that the binding is not solely due to (de)solvation processes. Our results indicate that classic H-bonded host–guest supramolecular chemistry takes place in ILs. This implies that strong H-bonds are only moderately affected by surroundings composed entirely of charges, which can be interpreted as an indication that the balance of Coulombic to covalent forces in strong H-bonds is not tipped towards the former.


2013 ◽  
Vol 68 (10) ◽  
pp. 1154-1162 ◽  
Author(s):  
Verena Adamer ◽  
Gerhard Laus ◽  
Ulrich J. Griesser ◽  
Herwig Schottenberger

Six 1-alkyl-4-tridecafluorooctyl-1,2,4-triazolium triflimides 2a-f and 4-amino-1-tridecafluorooctyl- 1,2,4-triazolium triflimide (4) were prepared from the respective iodides 1a-f (1a, 2a: n-propyl; 1b, 2b: n-butyl; 1c, 2c: n-hexyl; 1d, 2d: n-heptyl; 1e, 2e: n-octyl; 1f, 2f: n-decyl) and iodide 3 by ion metathesis. Compounds 2a and 4 are liquid at room temperature. Two liquid fluorous imidazolium salts bearing functionalized polar substituents were synthesized in an analogous manner, namely 1-(2- (diethylamino)ethyl)-3-(heptadecafluorodecyl)imidazolium triflimide (5b) and 1-(2-hydroxyethyl)- 3-(heptadecafluorodecyl)imidazolium triflimide (6b) from the respective bromides 5a and 6a. The bis(triflimide) 5c has a melting point slightly above room temperature. Three fluorous ionic liquids (ILs; 2a, 5b, and 6b) were subjected to vapor sorption analysis at 25 °C and exhibited dual affinity to water and, even much more pronounced, to methoxynonafluorobutane (hydrofluoroether HFE-7100). Thus, IL 6b absorbed 3:2% (by weight) water and 200% HFE, whereas ILs 2a and 5b absorbed 0.4 and 0:5% water, but 300 and 1200% HFE, respectively. Commercial 1-butyl-2,3- dimethyl-imidazolium triflimide and 1-ethyl-3-methyl-imidazolium triflimide were used as reference compounds and absorbed 0.9 and 2:2% water, respectively, but only 17% HFE.


Soft Matter ◽  
2015 ◽  
Vol 11 (7) ◽  
pp. 1293-1302 ◽  
Author(s):  
Yiyang Kong ◽  
Binjie Hu ◽  
Kwang-Leong Choy ◽  
Xiaoyu Li ◽  
Guangdi Chen

Room temperature ionic liquids (RTILs) are non-volatile organic salts, and few of them with low melting point may replace the conventional coalescing agents in waterborne coatings, thus preventing volatile organic compounds (VOCs) emission, caused by coalescing agents.


Author(s):  
Manuel Rothe ◽  
Eva Müller ◽  
Patrick Denk ◽  
Werner Kunz

Most of the commonly used Ionic Liquids (ILs) contain bulky organic cations with suitable anions. With our COMPLET (Concept of Melting Point Lowering due to Ethoxylation), we follow a different approach. We use simple, low-toxic, cheap and commercially available anions of the type Cx(EO)yCH2COO&ndash; to liquefy presumably any simple metal ion, independently of its charge. In the simplest case, the cation can be sodium or lithium, but synthesis of Ionic Liquids is also possible with cations of higher valences such as transition or rare earth metals. Anions with longer alkyl chains are surface active and form surface active ionic liquids (SAILs), which combine properties of ionic and nonionic surfactants at room temperature. They show significant structuring even in their pure state, i.e. in the absence of water or any other added solvent.


2017 ◽  
Vol 13 (2) ◽  
pp. 4671-4677 ◽  
Author(s):  
A. M. Abdelghany ◽  
A.H. Oraby ◽  
Awatif A Hindi ◽  
Doaa M El-Nagar ◽  
Fathia S Alhakami

Bimetallic nanoparticles of silver (Ag) and gold (Au) were synthesized at room temperature using Curcumin. Reduction process of silver and gold ions with different molar ratios leads to production of different nanostructures including alloys and core-shells. Produced nanoparticles were characterized simultaneously with FTIR, UV/vis. spectroscopy, transmission electron microscopy (TEM), and Energy-dispersive X-ray (EDAX). UV/vis. optical absorption spectra of as synthesized nanoparticles reveals presence of surface palsmon resonance (SPR) of both silver at (425 nm) and gold at (540 nm) with small shift and broadness of gold band after mixing with resucing and capping agent in natural extract which suggest presence of bimetallic nano structure (Au/Ag). FTIR and EDAX data approve the presence of bimetallic nano structure combined with curcumin extract. TEM micrographs shows that silver and gold can be synthesized separately in the form of nano particles using curcumin extract. Synthesis of gold nano particles in presence of silver effectively enhance and control formation of bi-metallic structure.


Author(s):  
Chandrakant Sarode ◽  
Sachin Yeole ◽  
Ganesh Chaudhari ◽  
Govinda Waghulde ◽  
Gaurav Gupta

Aims: To develop an efficient protocol, which involves an elegant exploration of the catalytic potential of both the room temperature and surfactant ionic liquids towards the synthesis of biologically important derivatives of 2-aminothiazole. Objective: Specific heat capacity data as a function of temperature for the synthesized 2- aminothiazole derivatives has been advanced by exploring their thermal profiles. Method: The thermal gravimetry analysis and differential scanning calorimetry techniques are used systematically. Results: The present strategy could prove to be a useful general strategy for researchers working in the field of surfactants and surfactant based ionic liquids towards their exploration in organic synthesis. In addition to that, effect of electronic parameters on the melting temperature of the corresponding 2-aminothiazole has been demonstrated with the help of thermal analysis. Specific heat capacity data as a function of temperature for the synthesized 2-aminothiazole derivatives has also been reported. Conclusion: Melting behavior of the synthesized 2-aminothiazole derivatives is to be described on the basis of electronic effects with the help of thermal analysis. Additionally, the specific heat capacity data can be helpful to the chemists, those are engaged in chemical modelling as well as docking studies. Furthermore, the data also helps to determine valuable thermodynamic parameters such as entropy and enthalpy.


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