Imidazolium-based ionic liquids having different anions 1-butyl-3-methylimidazolium ([BMIM]X: X = Cl⁻, Br⁻, I⁻, and BF₄⁻) their aqueous mixtures were investigated by IR absorption proton NMR spectroscopy.

We investigated the structures of ionic liquids (1-butyl-3-methylimidazolium iodide [BMIM][I] and 1-butyl-3-methylimidazolium tetrafluoroborate [BMIM][BF4]) their aqueous mixtures using attenuated total reflection (ATR) infrared absorption Raman spectroscopy. The ATR spectrum in CHx (x = 1, 2, 3) vibration region from 2800 to 3200 cm-1 was very different between [BMIM][BF4] even though all spectral features this were butyl chain imidazolium ring same cation. did not change appreciably...

Mixtures of ionic liquid (IL, 1-butyl-3-methylimidazolium tetrafluoroborate, [BMIM][BF4]) and water with varying concentrations were studied by attenuated total reflection infrared absorption Raman spectroscopy. Changes in the peak intensities positions CHx (x = 1, 2, 3) vibration modes cation IL OH molecules investigated. Peaks from normal-mode stretch vibrations CH bonds belonging to imidazolium ring did not change their positions, while those terminal methyl group butyl chain blueshifted...

Abstract A novel host material containing silicon‐cored spirobifluorene derivative (SBP‐TS‐PSB), is designed, synthesized, and characterized for red phosphorescent organic light‐emitting diodes (OLEDs). The SBP‐TS‐PSB has excellent thermal morphological stabilities exhibits high electroluminescence (EL) efficiency as a the OLEDs. electrophosphorescence properties of devices using iridium (III) complexes emitter are investigated these exhibit higher EL performances compared with reference...

The air/liquid interface of 1-alkyl-3-methylimidazolium tetrafluoroborates with the general formula [Cnmim]BF4 (n = 4−11) was studied using infrared−visible sum frequency generation (SFG) vibrational spectroscopy. probability gauche defect per CH2−CH2 bond in alkyl chain decreases as number carbon atoms increases. This observation suggests that interaction between chains is enhanced length becomes longer. frequencies C−H stretching modes observed SFG spectra are higher than those...

Surface sum-frequency generation spectroscopy and X-ray reflectivity were used to study the surface of [BMIM][X] ionic liquids (BMIM = 1-butyl-3-methylimidazolium cation, X BF4−, PF6−, I−). Sum-frequency signal strength from terminal methyl groups cation at indicates that topmost these is occupied by polar-oriented hydrophobic butyl chains having approximately 1/3 in-plane density fully packed alkyl as observed same method for hexadecanol Langmuir monolayer. data reveal a layer with larger...

Gold nanorod-attached PEGylated graphene-oxide (AuNR-PEG-GO) nanocomposites were tested for a photothermal platform both in vitro and vivo. Cytotoxicity of AuNR was reduced after encapsulation with PEG-GO along the removal cetyltrimethylammonium bromide (CTAB) from by HCl treatment. Cellular internalization CTAB-eliminated AuNR-PEG-GO examined using dark-field microscopy (DFM), confocal Raman transmission electron (TEM). To determine effect nanocomposites, A431 epidermoid carcinoma cells...

Silicalite-1 films (thickness = 400 nm) supported on both sides of glass plates (SL/G) were prepared, and hemicyanine dyes (HC-n) with different alkyl chain lengths (n, n 3, 6, 9, 12, 15, 18, 22, 24) included into the silicalite-1 by dipping SL/Gs each methanol solution HC-n (1 mM) for 1 d. The numbers per channel (NC) generally decreased increasing n; that is, they 6.4, 23.1, 15.4, 8.2, 5.7, 3.5, 0.9, 1.2 molecules channel, respectively. d33 value gradually increased but when > 18; 1.12,...

Sum-frequency generation vibrational spectroscopy was used to investigate the surface molecular structure of binary mixtures water and alcohol (methanol, ethanol, propanol) at air/liquid interface. In this study, it is shown that sum-frequency signal from molecules in CH-stretch vibration region always larger for than pure alcohol. For example, a propanol mixture 0.1 bulk mole fraction ∼3 times surface. However, ratio between signals taken different polarization combinations found be...

The surface structures of ionic liquids 1-CnH2n+1-3-methylimidazolium tetrafluoroborate (BF4−), trifluoromethanesulfonate (OTf) and bis(trifluoromethylsulfonyl)amide (TFSA) with n = 4, 8, 10 were investigated by ultraviolet photoemission spectroscopy (UPS) metastable atom electron (MAES). MAES spectra reveal that the anions cations share room-temperature (RTILs) a shorter alkyl chain at 4 although layer tends to cover outermost in case RTILs longer chains 8 10. Comparison UPS demonstrates...

The interfacial and bulk properties of the aqueous solutions imidazolium-based ionic liquids with different halide anions ([C12mim]Cl, [C12mim]Br, [C12mim]I) were investigated by surface tension electrical conductivity measurements. lowest (γcmc) maximum excess concentration (Γmax) values from measurements showed that [C12mim]I had highest activity. thermodynamic pontentials micellization (ΔG0m, ΔH0m, ΔS0m) indicated [C12mim]Cl [C12mim]Br was entropy-driven, while enthalpy-driven at 15 °C...

Water-soluble, carbazole-based two-photon excitable fluorescent probes MPVC-I ("turn-on") and MPVC-II ("turn-off") are rationally designed synthesized for the selective monitoring of carbon monoxide (CO). Both can effectively measure carboxyhemoglobin (HbCO) in blood animals exposed to a CO dose as low 100 ppm 10 min. The palladium catalyzed azidocarbonylation reaction was optimized improve sensing efficiency.

The liquid/liquid interfaces of room-temperature ionic liquids (RTILs) play a pivotal role in chemical reactions owing to their characteristic microscopic structure, yet the structure hydrophobic liquid/RTIL remains unclear. We studied at carbon tetrachloride (CCl4) and 1-alkyl-3-methylimidazolium bis(trifluoromethanesulfonyl)amide ([Cnmim][TFSA]; n = 4 8) RTILs using infrared-visible sum frequency generation (SFG) vibrational spectroscopy. A comparison SFG spectra CCl4/RTIL air/RTIL...

The air/liquid interface of a room temperature ionic liquid, 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([bmim]OTf), is investigated using infrared-visible sum frequency generation (SFG) spectroscopy. SFG spectra clearly show low-frequency modes [CF3-symmetric stretching (ss) mode and SO3-symmetric mode] the OTf anion, demonstrating existence anions polar oriented at interface. amplitude CF3-ss peak anion has opposite sign with respect to that SO3-ss peak, indicating surface have...

Sum-frequency vibrational spectroscopy, with the help of surface pressure-area (π-A) isotherm, was used to study lipid Langmuir monolayers composed molecules positively and negatively charged headgroups as well a 1:1 neutral mixture two. The spectral profiles CH(x) stretch vibrations are similar for all in liquid-condensed (LC) phase. They suggest monolayer structure closely packed alkyl chains that nearly all-trans oriented along normal. In liquid-expanded (LE) phase, spectra appear...

We examine the applicability of various model profiles for liquid/vapor interface by X-ray reflectivities on water and ethanol their mixtures at room temperature. Analysis reflecivities using density shows an error-function like profile is most adequate within experimental error. Our findings, together with recent observations from simulation studies liquid surfaces, strongly suggest that capillary-wave dynamics shapes interfacial in terms error function.

Surface crystallization at the vapor-liquid interface of ionic liquid (1-butyl-3-methylimidazolium hexafluorophosphate) is observed in synchrotron x-ray diffraction studies. Sharp Bragg reflections emerge grazing-angle patterns $37\text{ }\ifmmode^\circ\else\textdegree\fi{}\mathrm{C}$ above bulk melting temperature, indicating presence a long-range ordered phase surface coexistence with parent liquid. The unique structure where butyl chains attached to cations are expelled vapor side...

The observation of fluorescence in the visible spectral range imidazolium-based ionic liquids, which peak spectrum shifts with change excitation wavelength by over 200 nm, was reported Samanta and co-workers (Paul et al. J. Phys. Chem. B 2005, 109, 9148; Lett. 402, 375), aggregate structure bulk liquid suggested to explain this unique phenomenon. In work, employing 2D-scan spectroscopy, we identified long- short-wavelength components 1-butyl-3-methylimidazolium tetrafluoroborate...

We report on halide ion (Cl–, Br–, I–) adsorption from the subphase water to a cationic Langmuir monolayer consisting of 1,2-dipalmitoyl-3-trimethylammonium-propane (DPTAP) molecules at air/water interface. Reductions in OH signal sum-frequency spectra and surface pressure π–A isotherm follow order anion size, indicating preferable larger anions better screen charge DPTAP monolayer. Complementary X-ray fluorescence measurements Cl– I– reveal that integrated number adsorbed ions within...