Role of solvophilic moieties of gelators in the thermal stability of organogels.

Affinity analysis using Hansen solubility parameters (HSP) reveals that the gel-sol transition point of binary organogels is correlated with preferential interactions between the solvophilic moiety of gelators and solvents. The decomposition of gelators in HSP analysis can be effectively used for predicting the thermal stability of gels.

Uptake of Metal (Zn, Y, Ti) Oxide Nanoparticles by Poaceae and Cucurbitaceae Plants Based On Metal Properties and Surface Conditions.

Metal nanoparticles (NPs) may serve as biomarkers, as the surfaces can be chemically modified to enable an analysis of several biosystems, including plant pathogenesis. We supplied metal oxide NPs including those of ZnO, TiO, YO, and YO doped with europium to plants of eight species of the Poaceae and Cucurbitaceae families. The plants were grown using hydroponics, where NPs were incorporated into the cultivation media.

Relation between Anharmonicity of Free-Energy Profile and Spectroscopy in Solvation Dynamics: Differences in Spectral Broadening and Peak Shift in Transient Hole-Burning Spectroscopy Studied by Equilibrium Molecular Dynamics Simulation.

Solvation dynamics is used to monitor the time-dependent fluctuation of solvents, which plays an essential role in chemical reactions in solution. Transient hole-burning spectroscopy, in which a ground-state depletion (hole) formed by a laser pulse is observed, can be used to monitor solvation dynamics. Previous experiments demonstrated that the hole bandwidth relaxes an order of magnitude slower than the hole peak shift in organic solute-solvent systems.

Solvent-Dependent Properties and Higher-Order Structures of Aryl Alcohol + Surfactant Molecular Gels.

Molecular organogels, comprising small organic gelators in solvents, can be applied for dispersal of optical devices, such as emitters. Phenolic compounds and the surfactant bis(2-ethylhexyl) sulfosuccinate (AOT) are known examples of self-assembly organogels. However, conventional phenol + AOT gels in aromatic and acyclic alkane solvents are optically turbid, which is an obstacle for use as host materials in optical devices.

Reorientational Relaxation of Small Solutes in Viscoelastic Liquids.

The reorientational relaxation times of some small aromatic solutes are determined with nuclear magnetic resonance spectroscopy and time-resolved fluorescence anisotropy measurements in various solvents that exhibit viscoelasticity in the megahertz region. All the reorientational relaxation times in viscoelastic liquids are shorter than those predicted by the hydrodynamic Stokes-Einstein-Debye (SED) relation using the steady-state shear viscosity. The deviation from the SED relation becomes larger in solvents whose shear relaxation is slower.

Solvent dependence of Stokes shift for organic solute-solvent systems: A comparative study by spectroscopy and reference interaction-site model-self-consistent-field theory.

The Stokes shift magnitudes for coumarin 153 (C153) in 13 organic solvents with various polarities have been determined by means of steady-state spectroscopy and reference interaction-site model-self-consistent-field (RISM-SCF) theory. RISM-SCF calculations have reproduced experimental results fairly well, including individual solvent characteristics. It is empirically known that in some solvents, larger Stokes shift magnitudes are detected than anticipated on the basis of the solvent relative permittivity, ɛr.

Nona-coordinated chiral Eu(III) complexes with stereoselective ligand-ligand noncovalent interactions for enhanced circularly polarized luminescence.

Circularly polarized luminescence (CPL) of chiral Eu(III) complexes with nona- and octa-coordinated structures, [Eu(R/S-iPr-Pybox)(D-facam)(3)] (1-R/1-S; R/S-iPr-Pybox, 2,6-bis(4R/4S-isopropyl-2-oxazolin-2-yl)pyridine; D-facam, 3-trifluoroacetyl-d-camphor), [Eu(S,S-Me-Ph-Pybox)(D-facam)(3)] (2-SS; S,S-Me-Ph-Pybox, 2,6-bis(4S-methyl-5S-phenyl-2-oxazolin-2-yl)pyridine), and [Eu(Phen)(D-facam)(3)] (3; Phen, 1,10-phenanthroline) are reported, and their structural features are discussed on the basis of X-ray crystallographic analyses. These chiral Eu(III) complexes showed relatively intense photoluminescence due to their (5)D(0) → (7)F(1) (magnetic-dipole) and (5)D(0) → (7)F(2) (electric-dipole) transition. The dissymmetry factors of CPL (g(CPL)) at the former band of 1-R and 1-S were as large as -1.

Solvation dynamics in polar solvents studied by means of RISM/mode-coupling theory.

The extended reference interaction site model (RISM) theory coupled with the generalized Langevin/mode-coupling theory (MCT) is applied to the investigation of solvation dynamics in polar solvents. The RISM/ MCT framework used in this paper significantly upgrades the previous report by Nishiyama and co-workers [Nishiyama, K.; et al.