Development of Apparatus for Simultaneous Measurements of Raman Spectroscopy and High-Sensitivity Calorimetry

Endo, Takatsugu; Tozaki, Ken–ichi; Masaki, Takashi; Nishikawa, Keiko

doi:10.1143/jjap.47.1775

Cited by 30 publications

(38 citation statements)

References 24 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…To determine the general thermal phase behaviours of the samples, calorimetric measurements of sufficiently dried samples (1-2 mg) were performed using a laboratory-made calorimeter with a baseline stability of AE5 mW and a thermal stability of 0.001 K. 34 Measurements for both samples were performed at a scanning rate of 5 mK s À1 for the cooling and heating processes.…”

Section: Methodsmentioning

confidence: 99%

“…[23][24][25]28,29 These phenomena are proved to be closely related to the variety and flexibility of the conformations of the constituent ions. 1,30,31 Many research groups have focused on cations of imidazolium-based RTILs and investigated phase behaviours linked to conformational changes of the substituent groups of each cation, by calorimetry, [22][23][24][25][26][27] Raman spectroscopy 1,26,27,[32][33][34][35] and nuclear magnetic resonance (NMR) analyses. 29,[36][37][38][39][40][41][42][43][44][45][46][47][48] Previously, we revealed a relationship between the thermodynamic properties of imidazolium-based RTILs and their cation dynamics.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Anion and cation dynamics of sulfonylamide-based ionic liquids and the solid–liquid transitions

Imanari

Fujii

Mukai

et al. 2015

Phys. Chem. Chem. Phys.

Self Cite

View full text Add to dashboard Cite

Some of the important factors that characterise room-temperature ionic liquids (RTILs) are the variety of conformations adopted by the constituent ions and their flexibility. Using 1,3-dimethylimidazolium bis(fluorosulfonyl)amide ([C1mim][FSA]) and 1,3-dimethylimidazolium bis(trifluoromethylsulfonyl)amide ([C1mim][NTf2]) as samples, the longitudinal and transverse relaxation times (T1 and T2) for (19)F and (1)H were determined as a function of temperature and were correlated with the dynamics of the phase behaviours of the two RTILs. Because the anions and cations in the two compounds have (19)F and (1)H nuclei, respectively, their dynamics can be independently investigated and the relationships between them can be discussed. For [C1mim][FSA], the only observed phase changes included melting and crystallisation. The temperature dependences of T1 and T2 for (19)F were similar to those of T1 and T2 for (1)H, indicating similar dynamics due to the formation of strong anion-cation interactions. For [C1mim][NTf2], the T1 and T2 values for both (19)F and (1)H discontinuously changed at same temperatures, which were assigned to the crystallisation and melting points. However, the T1 curves for (19)F and (1)H were different in the crystalline region, suggesting independent dynamics for the anions and cations in [C1mim][NTf2]. In the crystalline state for each salt, the cation dynamics was distinctly separated into the framework movement of the imidazolium ring and the movement of the methyl groups, while the anion dynamics was characterised by the movement of the entire anion. The influence of the crystal structure on the dynamics of each salt was also considered.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Anion and cation dynamics of sulfonylamide-based ionic liquids and the solid–liquid transitions

Imanari

Fujii

Mukai

et al. 2015

Phys. Chem. Chem. Phys.

Self Cite

View full text Add to dashboard Cite

show abstract

“…(8)]. [19,20] To confirm the further details of the oxidation of 15 a with the nitroxyl-radical catalyst, we determined the time course of the reaction of 15 a and TEMPO in a5:1 molar ratio in MeCN under basic conditions by Raman spectroscopic analysis [21] ( Figure 1). After 1.5 h, peaks assignable to oxoammonium chloride were observed (553.8 and 695.7 cm À1 )t ogether with those of 14 a (541.2 and 797.4 cm À1 ), but peaks attributable to the reduced form of TEMPO (TEMPOH;6 69.6 and 782.1 cm À1 )w ere not detected at all (see the Supporting Information).…”

Section: Angewandte Chemiementioning

confidence: 99%

Nitroxyl‐Radical‐Catalyzed Oxidative Coupling of Amides with Silylated Nucleophiles through N‐Halogenation

et al. 2016

View full text Add to dashboard Cite

A nitroxyl-radical-catalyzed oxidative coupling reaction between amines with an N-protecting electron-withdrawing group (EWG) and silylated nucleophiles was developed to furnish coupling products in high yields, thus opening up new frontiers in organocatalyzed reactions. This reaction proceeded through the activation of N-halogenated amides by a nitroxyl-radical catalyst, followed by carbon-carbon coupling with silylated nucleophiles. Studies of the reaction mechanism indicated that the nitroxyl radical activates N-halogenated amides, which are generated from N-EWG-protected amides and a halogenation reagent, to give the corresponding imines.

show abstract

“…The Nishikawa group investigated the premelting behavior of 1-alkyl-3-methylimidazolium salts with a custom-made DSC apparatus with nanowatt sensitivity. [77][78][79][80] They used low heating and cooling rates (typically in the 0.06-0.3 K min À1 range) which allowed measuring under quasi-static conditions. Supported by Raman spectroscopy and gas-phase calculations, they suggested that the broadness of the melting peaks was due to the change between different conformations of the cation's alkyl group.…”

Section: Dsc Calibrationmentioning

confidence: 99%

Is Universal, Simple Melting Point Prediction Possible?

et al. 2011

View full text Add to dashboard Cite

An investigation of the melting points of 520 organic 1:1 salts is presented with the aim of developing a universal, simple, physically well-founded prediction scheme. The general reliability and reproducibility of the recorded experimental data are discussed with respect to purity, phase behavior, disorder and thermal history of a given substance. Additionally, mistakes, systematic errors, or lack of conventions can lead to considerable differences in the experimental measurements. A rough error bar for the reproducibility of the melting points of organic salts of ±5 to ±15 °C can be assigned. With this restraint, we developed two simple, semiempirical, five- and nine-parameter schemes with easy-to-calculate quantities. With these, we could predict the melting temperature of a given organic salt in the temperature range of -25 to +300 °C with an average error of 33.5 °C and a relative error of 9.3%. All calculated quantities are assessed with the help of conventional DFT, COSMO and COSMO-RS calculations, and are currently implemented into the IL-Prop module of the upcoming version of COSMOtherm. These prediction schemes are suitable for high-throughput computational screening of substances in the context of "computer-aided synthesis". Therefore, they are valuable tools to find a compound with a suitable melting point before its first synthesis.

show abstract

Development of Apparatus for Simultaneous Measurements of Raman Spectroscopy and High-Sensitivity Calorimetry

Cited by 30 publications

References 24 publications

Anion and cation dynamics of sulfonylamide-based ionic liquids and the solid–liquid transitions

Anion and cation dynamics of sulfonylamide-based ionic liquids and the solid–liquid transitions

Nitroxyl‐Radical‐Catalyzed Oxidative Coupling of Amides with Silylated Nucleophiles through N‐Halogenation

Is Universal, Simple Melting Point Prediction Possible?

Contact Info

Product

Resources

About