Honeycomb layered oxides: structure, energy storage, transport, topology and relevant insights.

The advent of nanotechnology has hurtled the discovery and development of nanostructured materials with stellar chemical and physical functionalities in a bid to address issues in energy, environment, telecommunications and healthcare. In this quest, a class of two-dimensional layered materials consisting of alkali or coinage metal atoms sandwiched between slabs exclusively made of transition metal and chalcogen (or pnictogen) atoms arranged in a honeycomb fashion have emerged as materials exhibiting fascinatingly rich crystal chemistry, high-voltage electrochemistry, fast cation diffusion besides playing host to varied exotic electromagnetic and topological phenomena. Currently, with a niche application in energy storage as high-voltage materials, this class of honeycomb layered oxides serves as ideal pedagogical exemplars of the innumerable capabilities of nanomaterials drawing immense interest in multiple fields ranging from materials science, solid-state chemistry, electrochemistry and condensed matter physics. In this review, we delineate the relevant chemistry and physics of honeycomb layered oxides, and discuss their functionalities for tunable electrochemistry, superfast ionic conduction, electromagnetism and topology. Moreover, we elucidate the unexplored albeit vastly promising crystal chemistry space whilst outlining effective ways to identify regions within this compositional space, particularly where interesting electromagnetic and topological properties could be lurking within the aforementioned alkali and coinage-metal honeycomb layered oxide structures. We conclude by pointing towards possible future research directions, particularly the prospective realisation of Kitaev-Heisenberg-Dzyaloshinskii-Moriya interactions with single crystals and Floquet theory in closely-related honeycomb layered oxide materials.

Modulation of Electron Injection Dynamics of Ru-Based Dye/TiO2 System in the Presence of Three Different Organic Solvents: Role of Solvent Dipole Moment and Donor Number.

In the present work, femtosecond transient absorption spectroscopy (fs-TAS) has been employed to investigate the electron injection efficiency (EIE) both from the singlet and triplet excited states of a well-known ruthenium dye (N719) to the conduction band (CB) of nanostructured TiO(2) in presence of three different organic solvents [γ-butylactone (GBL), 3-methoxypropionitrile (MPN), and dimethylformamide (DMF)] with different donor numbers (DNs) and dipole moments (DMs). The DM and DN of a solvent modulates the CB edge energy of TiO(2), and this effect reflects well in the fs-TAS results, which shows an EIE trend following the order GBL≥MPN≫DMF, that is, highest in GBL and lowest in DMF solvent environments. Fs-TAS results indicate a lower contribution of electron injection from both the singlet and triplet states in DMF, for which the dominant adsorption of DMF molecules on the TiO(2) surface seems to play an important role in the mechanism.

Direct observation of Cu in high-silica chabazite zeolite by electron ptychography using Wigner distribution deconvolution.

Direct observation of Cu in Cu-chabazite (CHA) zeolite has been achieved by electron ptychography using the Wigner distribution deconvolution. The imaging properties of ptychographically reconstructed images were evaluated by comparing the intensities of six-membered-ring columns of the zeolite with and without Cu using simulated ptychography images. It was concluded that although false contrast may appear at Cu-free columns for some acquisition conditions, ptychography can discriminate columns with and without Cu. Experimental observation of CHA with and without Cu was performed. Images obtained from the Cu-containing sample showed contrast at the six-membered-rings, while no contrast was observed for the Cu-free sample. The results show that ptychography is a promising technique for visualizing the atomic structures of beam-sensitive materials.

Impact of background parenchymal enhancement levels on the diagnosis of contrast-enhanced digital mammography in evaluations of breast cancer: comparison with contrast-enhanced breast MRI.

PURPOSE: To compare the diagnostic performances of contrast-enhanced digital mammography (CEDM) and breast MRI in evaluations of breast cancer, with a focus on the impact of background parenchymal enhancement (BPE) levels. METHODS: The present study included women who underwent CEDM and breast MRI to evaluate the disease extent of breast cancer between January 2018 and December 2019. Readers judged BPE levels (minimal-mild or moderate-marked) on CEDM, and were asked to assign findings suggesting malignancy using the following criteria: (1) enhancement other than BPE and (2) BI-RADS 4/5 calcifications without enhancement. On MRI, BI-RADS 3 and BI-RADS 4/5 lesions were evaluated as benign and malignant, respectively. The diagnostic performances of CEDM and MRI were compared separately between women with minimal-mild BPE and those with moderate-marked BPE. RESULTS: Sixty-nine patients comprising 43 postmenopausal and 26 premenopausal women were included in the present study. In total, 195 lesions (94 malignant and 101 benign) were identified. The sensitivity and specificity of CEDM for the diagnosis of all lesions were 90.8 and 91.5% with minimal-mild BPE and 79.3 and 76.2% with moderate-marked BPE, respectively. The sensitivity and specificity of MRI were 90.0% and 71.0% with minimal-mild BPE and 87.5% and 78.1% with moderate-marked BPE, respectively. The accuracy of CEDM was significantly superior to that of MRI in women with minimal-mild BPE on both CEDM and MRI (p = 0.002). Regarding the negative impact of a correct diagnosis on CEDM, the odds ratio of "moderate-marked BPE" was 0.382. CONCLUSION: In patients with minimal-mild BPE, the diagnostic performance of CEDM was superior to that of MRI.

Effects of conformational flexibility of alkyl chains of cations on diffusion of ions in ionic liquids.

Molecular dynamics simulations of ionic liquids [1-alkyl-3-methylimidazolium (alkyl = ethyl, butyl and hexyl), N-butylpyridinium, N-butyl-N,N,N-trimethylammonium and N-butyl-N-methylpyrrolidinium cations combined with the (CF(3)SO(2))(2)N(-) (TFSA) anion] show that the conformational flexibility of the alkyl chains in the cations is one of the important factors determining the diffusion of ions. Artificial constraint imposed on the internal rotation of alkyl chains significantly decreases the self-diffusion coefficients of cations and anions. The internal rotation of the C-N bond connecting the alkyl chain and the aromatic ring has large effects on the diffusion of ions in imidazolium and pyridinium based ionic liquids. The calculated self-diffusion coefficients of cations and anions decrease 20-40% by imposing the torsional constraint of the C-N bond. On the other hand the torsional constraint of the C-N bond does not largely change the diffusion of ions in the quaternary alkyl ammonium based ionic liquids. The conformational flexibility of the terminal C-C-C-C bond of the alkyl chains has large effects on the diffusion of ions in the quaternary alkyl ammonium based ionic liquids. The influence of the electrostatic interactions and the high density of ionic liquids on the diffusion of ions were studied. The electrostatic interactions have the paramount importance on the slow diffusion of ions in ionic liquids, while the high density of ionic liquids is also responsible for the slow diffusion. The electrostatic interactions and the high density of ionic liquids enhance the effects of the torsional constraint on the diffusion of ions, which suggests that the charge-ordering structure and small free volume originated in the strong electrostatic interactions are the causes of the significant effects of the conformational flexibility on the diffusion of ions in ionic liquids.

The association between MRI findings and breast cancer subtypes: focused on the combination patterns on diffusion-weighted and T2-weighted images.

PURPOSE: To assess morphology on diffusion-weighted imaging (DWI) and intratumoral signal intensity (SI) on T2-weighted images (T2WI) of breast carcinomas, and to evaluate the association between the combined DWI and T2WI findings and breast cancer subtypes. METHODS: Two hundred and eighty breast cancer patients who underwent breast MRI prior to therapy were included in this retrospective study. All had invasive carcinomas, which were classified into five subtypes: Luminal A-like (n = 149), Luminal B-like (n = 63), Hormone receptor-positive HER2 (n = 31), Hormone receptor-negative HER2 (n = 13), or Triple-negative (TN) (n = 24). Based on the morphology on DWI, the tumors were classified into two patterns: DWI-homogeneous or DWI-heterogeneous. If DWI-heterogeneous, an assessment of intratumoral SI on T2WI was performed: tumors with intratumoral high/low SI on T2WI were classified as Hete-H/Hete-L, respectively. The associations between (1) the morphological patterns on DWI and the five subtypes, and (2) the intratumoral SI patterns on T2WI and the five subtypes in DWI-heterogeneous were evaluated. RESULTS: There was a significant association between (1) the morphological patterns on DWI and the five subtypes (p < 0.0001), and (2) the intratumoral SI patterns on T2WI and the five subtypes in DWI-heterogeneous (p < 0.0001). DWI-homogeneous was dominant in Luminal A-like (67.1%), and Hete-H was dominant in TN type (75%). Hete-H, suggesting the presence of intratumoral necrosis, included high proliferative and/or aggressive subtypes more frequently (80%) than Hete-L, suggesting the presence of fibrotic focus. Fibrotic focus was seen more commonly in the luminal subtypes. CONCLUSION: The combined findings on DWI and T2WI revealed breast carcinomas that were associated with particular subtypes.

Analytical Measurements to Elucidate Structural Behavior of 2,5-Dimethoxy-1,4-benzoquinone During Charge and Discharge.

Organic compounds as electrode materials can contribute to sustainability because they are nontoxic and environmentally abundant. The working mechanism during charge-discharge for reported organic compounds as electrode materials is yet to be completely understood. In this study, the structural behavior of 2,5-dimethoxy-1,4-benzoquinone (DMBQ) during charge-discharge is investigated by using NMR spectroscopy, energy-dispersive X-ray spectroscopy, magnetic measurements, operando Raman spectroscopy, and operando X-ray diffraction. For both lithium and sodium systems, DMBQ works as a cathode accompanied with the insertion and deinsertion of Li and Na ions during charge-discharge processes. The DMBQ sample is found to be in two-phase coexistence state at the higher voltage plateau, and the radical monoanion and dianion phases have no long-distance ordering. These structures reversibly change into the original neutral phase with long-distance ordering. These techniques can show the charge-discharge mechanism and the factors that determine the deterioration of organic batteries, thus guiding the design of future high-performance organic batteries.

Real-World Outcomes of Treating Advanced Breast Cancer Patients With Palbociclib: A Multicenter Retrospective Cohort Study in Japan-The KBCOG-14 Study.

BACKGROUND: Clinical studies have shown that palbociclib improves progression-free survival in hormone receptor-positive (HR+), human epidermal growth factor receptor 2-negative (HER2-) patients with advanced breast cancer (ABC). However, there are insufficient data on its use in a real-world setting in Japan. The aim of this study was to investigate the effectiveness, predictive factors, and safety of palbociclib among Japanese patients in routine clinical practice. METHODS: Between December 1, 2017, and April 30, 2019, we recruited patients from 9 hospitals and retrospectively evaluated the data on HR+/HER2- patients with ABC who received palbociclib for at least 1 week. The correlation between time-to-treatment discontinuation (TTD) and clinical background was investigated via univariate and multivariate analyses using Cox hazards models. RESULTS: A total of 177 women were available for analysis. Of these patients, 58 (33%) patients were treated with palbociclib with an aromatase inhibitor and 117 (66%) patients were treated with palbociclib and a selective estrogen receptor degrader. Approximately three-fourths of the patients (n = 130, 73%) received palbociclib as third- or later-line therapy. One-third of the patients had 3 or more metastatic sites (n = 59, 33%), and one-third of the patients had liver metastasis (n = 59, 33%). The median follow-up duration at the time of data cutoff was 8.9 months, the median TTD was 6.3 months, and the median overall survival was not reached. Liver metastasis (hazard ratio [HR]: 1.54 [95% confidence interval {CI}: 1.03-2.27]), high serum lactate dehydrogenase (LDH) level (>300 U/L) (HR: 2.58 [95% CI: 1.49-4.26]), and high neutrophil-to-lymphocyte ratio (NLR) (⩾3.0) (HR: 1.76 [95% CI: 1.13-2.69]) were significantly associated with shorter TTD. The most common hematologic adverse event was neutropenia, which occurred in 93% of the patients. CONCLUSION: Based on the results of the pivotal phase 3 trials, the median TTD recorded in this study was shorter than expected. Our results suggest that liver metastasis, serum LDH level, and NLR may be predictive factors for HR+/HER2- ABC treatment outcomes.

Direct measurements of ionic mobility of ionic liquids using the electric field applying pulsed gradient spin-echo NMR.

Ionic mobilities of the ionic liquids, 1-ethyl-3-methylimidazolium tetrafluoroborate, 1-ethyl-3-methylimidazolium bis(fluorosulfonyl)amide,1-ethyl-3-methylimidazolium fluorosulfonyl-(trifluoromethylsulfonyl)amide, 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl) -amide, were measured using the electric field applying pulsed gradient spin-echo NMR technique. Observed mobilities were more than 1 order of magnitude greater than the values estimated from the diffusion coefficients measured under the equilibrium state without the electric field. Electric field dependence of the ionic mobility showed that the high mobility appeared above the threshold of the field strength with keeping the constant values. This indicates that the ions are orientated by the application of the electric field may be due to the dielectric polarization.

Ab initio study of EMIM-BF4 crystal interaction with a Li (100) surface as a model for ionic liquid/Li interfaces in Li-ion batteries.

We examined the atomic and electronic structures of an interface between a 1-ethyl-3-methyl imidazolium tetrafluoroborate (EMIM-BF(4)) ionic-liquid crystal and a Li(100) surface by periodic density-functional calculations, as a model for a room-temperature ionic-liquid (RTIL) electrolyte/Li interface at a Li-ion battery electrode. Results are compared with our previous theoretical study of the EMIM-BF(4) molecular adsorption on Li surfaces [H. Valencia et al., Phys. Rev. B 78, 205402 (2008)]. For the EMIM-BF(4) crystal structure, the present projector augmented wave scheme with the generalized gradient approximation can reproduce rather correct intramolecular structures as well as satisfactory short-ranged intermolecular distances, while long-range intermolecular distances are overestimated due to the lack of correct description of long-range dispersive interactions. We constructed a coherent crystal/crystal interface model where four EMIM-BF(4) pairs are stacked on a p(4x3) Li (100) surface cell so as to simulate RTIL-layer deposition on a Li surface. We observed significant attraction of surface Li ions toward contacting BF(4)(-) anions, counterbalanced by electron transfer toward EMIM(+) cations near the interface, revealing the tendency of easy ionization of Li and Li(x)-BF(4) cluster formation, coupled with the reduction of EMIM(+). These features are similar to those observed in the EMIM-BF(4) molecular adsorption, while these have been proved to occur in the crystal-layer adsorption. We examined the adhesive energy, wetability, and detailed electronic structure at the crystal/crystal interface.

Solvation-Structure Modification by Concentrating Mg(TFSA)2-MgCl2-Triglyme Ternary Electrolyte.

Mg(TFSA)2/triglyme(G3)-based electrolytes (TFSA: bis (trifluoromethanesulfonyl) amide) are one of candidates for magnesium rechargeable batteries, but the passivation of Mg-metal anode due to the TFSA anion is fatal in practical use. In this work we show that at elevated temperatures around 150 °C a comparable amount of MgCl2 salt can be dissolved in concentrated Mg(TFSA)2/G3 solutions, and the passivation of Mg metal is markedly suppressed in such highly concentrated solutions (1 ≤ G3/Mg-salts ≤ 2) in comparison with in the dilute solutions (G3/Mg-salts ≫ 2). By decreasing the amount of G3 solvent, the solvation structure of Mg2+ ions is modified in that free TFSA anions are drastically lowered, which would consequently decrease the reactivity of TFSA anions. We also demonstrate that a full-cell using MgCo2O4 cathode with the electrolyte of Mg(TFSA)2/MgCl2/G3 1:1:2 at 150 °C delivers a cell voltage of ∼2 V versus Mg-metal anode.

Ionic Liquid-Based Electrolytes Containing Surface-Functionalized Inorganic Nanofibers for Quasisolid Lithium Batteries.

In the present study, surface amino-functionalized silica nanofibers (f-SiO2NFs, average diameter = 400 and 1000 nm) are used as one-dimensional (1-D) fillers of ionic liquid (IL)-based quasisolid electrolytes. On adding f-SiO2NFs to an IL (1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide, EMITFSA) containing lithium bis(trifluoromethanesulfonyl)-amide (LiTFSA), the well-dispersed 1-D nanofillers easily form a three-dimensional network structure in the IL, function as physical cross-linkers, and increase the viscosity of the composites, consequently providing a quasisolid state at a 3.5 wt % fraction of the NFs. Rheological measurements demonstrate that the prepared composites exhibit "gel-like" characteristics at 40-150 °C. All prepared composites show high ionic conductivities, on the order of 10-3 S cm-1, around room temperature. To investigate the additive effect of f-SiO2NFs in the composites, the lithium transference numbers are also evaluated. It is found that thinner NFs enhance the transference numbers of the composites. In addition, quasisolid lithium-ion cells containing the prepared composites demonstrate relatively high rate characteristics and good cycling performance at high temperature (125 °C).

Alkali Metal Salts with Designable Aryltrifluoroborate Anions.

Aryltrifluoroborate ([ArBF3](-)) has a designable basic anion structure. Various [ArBF3](-)-based anions were synthesized to create novel alkali metal salts using a simple and safe process. Nearly 40 novel alkali metal salts were successfully obtained, and their physicochemical characteristics, particularly their thermal properties, were elucidated. These salts have lower melting points than those of simple inorganic alkali halide salts, such as KCl and LiCl, because of the weaker interactions between the alkali metal cations and the [ArBF3](-) anions and the anions' larger entropy. Moreover, interestingly, potassium cations were electrochemically reduced in the potassium (meta-ethoxyphenyl)trifluoroborate (K[m-OEtC6H4BF3]) molten salt at 433 K. These findings contribute substantially to furthering molten salt chemistry, ionic liquid chemistry, and electrochemistry.

A polymorphism of the 5' flanking region of tumour necrosis factor α gene is associated with thyroid-associated ophthalmopathy in Japanese.

OBJECTIVE: We have studied the polymorphism of the 5' flanking region of the tumour necrosis factor (TNF)-α gene in order to better understand the genetic background of autoimmune thyroid disorders and thyroid-associated ophthalmopathy. PATIENTS AND METHODS: We studied the polymorphism of the 5' flanking region of the TNF-α gene at positions - 1031 (T to C change, termed as - 1031C), - 863 (C to A, - 863 A), - 857 (C to T, - 857T), - 308 (G to A, - 308 A) and - 238 (G to A, - 238 A) in Japanese patients with Graves' disease [n = 173, 62 of whom had associated ophthalmopathy (American Thyroid Association (ATA) class III or greater)] and healthy control subjects (n = 575), using a polymerase chain reaction sequence-specific oligonucleotide probe method. RESULTS: The allele frequency of - 857T in the Graves' disease patients (22.5% vs. 17.7%, OR = 1.35, P = 0.045, corrected P = 0.23) was slightly greater than in the Japanese healthy subjects, respectively. However, the difference was not statistically significant. In Graves' disease patients with evident ophthalmopathy (ATA class III or greater), the allele frequencies of - 1031C and - 863 A were significantly greater than those with no or mild ophthalmopathy (ATA class 0-II) (31.5% vs. 13.5%, OR =2.94, P < 0.0001, corrected P < 0.0005; 23.4% vs. 11.7%, OR =2.30, P = 0.0044, corrected P = 0.022, respectively) and in control subjects. The strength of the association of the polymorphism - 1031C increased with the severity of ophthalmopathy, with odds ratios of 2.36 for ATA class III, and 5.43 for ATA class IV-VI, respectively, compared with Graves' disease with no or mild ophthalmopathy (ATA class 0-II). Although the phenotype frequency of DRB1*0901 was not different among Graves' disease patients with or without ophthalmopathy and control subjects, the phenotype frequency of DRB1*0901(-)/-1031C(+) was significantly increased in Graves' disease patients with ophthalmopathy compared to those with no or mild ophthalmopathy (OR = 4.91, P = 0.0005) or control subjects (OR = 4.59, P < 0.0001). CONCLUSIONS: These results suggest that the - 1031C or - 863 A alleles, or a gene in linkage disequilibrium with the TNF-α gene, predispose to the development of ophthalmopathy in Japanese patients with Graves' disease.

Room temperature ionic liquids based on small aliphatic ammonium cations and asymmetric amide anions.

The asymmetric amide anion (CF3SO2-N(-)-COCF3) has excellent abilities to lower both the melting points and viscosities of room temperature ionic liquids (RTILs) combining with small aliphatic ammonium cations that have not yet been reported to form RTILs.

Cation and anion dependence of stable geometries and stabilization energies of alkali metal cation complexes with FSA(-), FTA(-), and TFSA(-) anions: relationship with physicochemical properties of molten salts.

Stable geometries and stabilization energies (Eform) of the alkali metal complexes with bis(fluorosulfonyl)amide, (fluorosulfonyl)(trifluoromethylslufonyl)amide and bis(trifluoromethylsulfonyl)amide (FSA(-), FTA(-) and TFSA(-)) were studied by ab initio molecular orbital calculations. The FSA(-) complexes prefer the bidentate structures in which two oxygen atoms of two SO2 groups have contact with the metal cation. The FTA(-) and TFSA(-) complexes with Li(+) and Na(+) prefer the bidentate structures, while the FTA(-) and TFSA(-) complexes with Cs(+) prefer tridentate structures in which the metal cation has contact with two oxygen atoms of an SO2 group and one oxygen atom of another SO2 group. The two structures are nearly isoenergetic in the FTA(-) and TFSA(-) complexes with K(+) and Rb(+). The magnitude of Eform depends on the alkali metal cation significantly. The Eform calculated for the most stable TFSA(-) complexes with Li(+), Na(+), K(+), Rb(+) and Cs(+) cations at the MP2/6-311G** level are -137.2, -110.5, -101.1, -89.6, and -84.1 kcal/mol, respectively. The viscosity and ionic conductivity of the alkali TFSA molten salts have strong correlation with the magnitude of the attraction. The viscosity increases and the ionic conductivity decreases with the increase of the attraction. The melting points of the alkali TFSA and alkali BETA molten salts also have correlation with the magnitude of the Eform, which strongly suggests that the magnitude of the attraction play important roles in determining the melting points of these molten salts. The anion dependence of the Eform calculated for the complexes is small (less than 2.9 kcal/mol). This shows that the magnitude of the attraction is not the cause of the low melting points of alkali FTA molten salts compared with those of corresponding alkali TFSA molten salts. The electrostatic interactions are the major source of the attraction in the complexes. The electrostatic energies for the most stable TFSA(-) complexes with the five alkali metal cations are -140.3, -119.4, -104.1, -96.9, and -91.1 kcal/mol, respectively. The induction interactions also contribute to the attraction. In particular, the induction interactions are large in the Li(+) complexes. The induction energies for the five complexes are -46.6, -25.2, -17.5, -13.3, and -10.4 kcal/mol, respectively.

Highly Efficient and Specific Gelation of Ionic Liquids by Polymeric Electrolytes to Form Ionogels with Substantially High Gel-Sol Transition Temperatures and Rheological Properties Like Self-Standing Ability and Rapid Recovery.

We synthesized gel-forming polyelectrolytes having N,N'-(trans-cyclohexane-1,4-diyl)dibenzamide linkages, with chloride, bis(trifluoromethanesulfonyl)amide, bis(fluorosulfonyl)amide, or tetrafluoroborate anions that could gelatinize a variety of ionic liquids at very low concentrations. The temperatures at which these ionogels transitioned into isotropic fluids were greater than 100 °C even at concentrations as low as 5 g/L. In addition, the ionogels exhibited high mechanical strength without a significant loss in their ionic conductivities, along with the rapid recovery.

Interactions of perfluoroalkyltrifluoroborate anions with li ion and imidazolium cation: effects of perfluoroalkyl chain on motion of ions in ionic liquids.

The stabilization energies (E(form)) for the formation of the perfluoroalkyltrifluoroborate complexes with Li(+) and 1-ethyl-3-methylimidazolium cation (emim(+)) were calculated at the MP2/6-311G** level. The E(form) values calculated for the Li[BF(4)], Li[BF(3)CF(3)], Li[BF(3)C(2)F(5)], Li[BF(3)C(3)F(7)], and Li[BF(3)C(4)F(9)] complexes were -144.1, -139.3, -137.4, -136.3, and -135.4 kcal/mol, respectively. The E(form) values calculated for the [emim][BF(4)], [emim][BF(3)CF(3)], [emim][BF(3)C(2)F(5)], [emim][BF(3)C(3)F(7)], and [emim][BF(3)C(4)F(9)] complexes were -85.2, -81.2, -79.7, -79.7, and -79.2 kcal/mol, respectively. The electrostatic interactions are the major source of the attraction in the complexes, whereas the contribution of the induction interactions to the attraction is not negligible. The interactions of the perfluoroalkyltrifluoroborate anions with Li(+) and emim(+) are substantially weaker than those of the BF(4)(-) because of the weaker electrostatic interactions. The analysis of the interactions suggests that the weaker interactions between the BF(3)CF(3)(-) and emim(+) compared with those between the BF(4)(-) and emim(+) are the cause of the lower viscosity of the [emim][BF(3)CF(3)] ionic liquid compared with the [emim][BF(4)] ionic liquid. The order of experimental self-diffusion coefficients of the cations and anions in the ionic liquids is BF(4)(-) < BF(3)CF(3)(-) approximately BF(3)C(2)F(5)(-) > BF(3)C(3)F(7)(-) > BF(3)C(4)F(9)(-), which is well reproduced by the molecular dynamic simulations. The analysis of the rotational relaxation of emim(+) suggests that the translational diffusion of cations and anions is associated with the rotational diffusion of emim(+).

Alkoxy chains in ionic liquid anions; effect of introducing ether oxygen into perfluoroalkylborate on physical and thermal properties.

The melting point and viscosity of [CF(3)OCF(2)CF(2)BF(3)](-) based ionic liquids are significantly lower than those of [CF(3)CF(2)CF(2)CF(2)BF(3)](-) based ionic liquids, indicating that the oxygen atom plays a key role in the preparation of low-melting and low-viscosity ionic liquids.