A role of intermolecular interaction modulating thermal diffusivity in organosuperelastic and organoferroelastic cocrystals.

Although the finding of superelasticity and ferroelasticity in organic crystals has been serendipitous, an increasing number of organic crystals with such deformation properties have been witnessed. Understanding the structure-property relationship can aid in the rational selection of intermolecular interactions to design organic crystals with desired superelastic or ferroelastic properties. In this study, we investigated the mechanical deformation in two cocrystals, prepared with the parent compound, 1,4-diiodotetrafluorobenzene with two coformers, 1,2-bis(4-pyridyl)ethane and pyrene.

Decomposition analysis on the excitation behaviors of thiazolothiazole (TTz)-based dyes the time-dependent dielectric density functional theory approach.

Thiazolothiazole (TTz)-based materials have been attracting much attention because of their widespread applications. In this paper, we discuss the excited electronic behaviors of asymmetric TTz dyes in solvents based on the time-dependent dielectric density functional theory method. Based on dipole moment and charge distribution (population) analyses, we discuss large intramolecular electron transfers, which are triggered by photon excitations, toward the acceptor part of dyes.

Mechanical deformation and multiple thermal restoration of organic crystals: reversible multi-stage shape-changing effect with luminescence-color changes.

Shape-memory materials can be mechanically deformed and subsequently reverse the deformation upon changing the temperature. Shape-memory materials have attracted considerable attention for basic research and industrial applications, and polymer and alloy shape-memory materials have been well studied; however, it is formidably challenging to develop functional shape-memory materials, such as materials with multi-stage and anisotropic shape changes and shape changes accompanied by changes in color and light emission. Here, we found a reversible multi-stage shape-changing effect after mechanical deformation in a molecular crystal induced by multi-step thermal phase transitions with reversible shape changes and luminescence-color changes.

Fullerene C/porphyrin hybrid nanoarchitectures: single-cocrystal nanoribbons with ambipolar charge transport properties.

In recent years, supramolecular cocrystals containing organic donors and acceptors have been explored as active components in organic field-effect transistors (FETs). Herein, we report the synthesis of novel single-cocrystal nanoribbons with ambipolar charge transport characteristics from C and 5,10,15,20-tetrakis(3,5-dimethoxyphenyl)porphyrin (3,5-TPP) in a 3 : 2 ratio. The C/3,5-TPP nanoribbons exhibited a new strong absorption band in the near-infrared region, indicating the presence of charge-transfer interactions between C and 3,5-TPP in the cocrystals.

Theoretical study of the H/D isotope effect of CH/CD adsorption on a Rh(111) surface using a combined plane wave and localized basis sets method.

We analysed the H/D isotope effect of CH/CD adsorption on a Rh(111) surface using our combined plane wave and localized basis sets method, that we proposed for the consideration of delocalized electrons on a surface and the quantum effect of protons (deuterons) in metal-molecule interactions. We observed that the adsorption distance and energy of CD were larger and lower than those of CH, respectively. This is in reasonable agreement with the corresponding experimental results of cyclohexane adsorption.

Model-based research toward design of innovative materials: molecular weight prediction of bridged polysilsesquioxanes.

Toward the design and manipulation of innovative materials, we propose a new concept called "model-based research (MBR)". In MBR, measurable physical and chemical properties of materials are mathematically modelled by explanatory parameters obtained by computer simulation from an atomistic point of view. To demonstrate the potential of MBR, we modelled the molecular weights of a series of polysilsesquioxanes with respect to the HO/silane molar ratio employed for the polymerization of monomers bis(triethoxysilyl)methane, ethane, ethylene, and acetylene (BTES-M, -E1, -E2, and -E3), as an example.

Computational simulation of anion binding association mechanisms contributing toward rotation of pyrrole rings in dipyrrolyldiketone BF complexes.

Dipyrrolyldiketone BF complexes have a characteristic association mechanism with anions; an anion is tightly captured by the NH bonding of the two rotated pyrrole rings and the CH bonding of the backbone in dipyrrolyldiketone BF complexes. In order to elucidate this anion association mechanism in dipyrrolyldiketone BF complexes, the relative stability of several conformers of the dipyrrolyldiketone BF complex and anion complexes are initially calculated by quantum mechanical density functional theory (DFT). Second, molecular dynamics (MD) simulations were performed for systems comprising a dipyrrolyldiketone BF complex and Cl with several types of countercations in CHCl.

A stochastic analysis based on a one-dimensional random walk model of the persistent phosphorescence of Mn ions doped in zinc magnesium phosphate.

We investigate the mechanism of the persistent phosphorescence (PP) of β-Zn3(PO4)2:Mn2+ and γ-(Zn2+,Mg2+)3(PO4)2:Mn2+ systems via stochastic analysis. An electron hopping mechanism, recombining electrons with Mn3+ ions, is proposed to elucidate the long-tailed decay feature that represents a non-exponential decay curve for the PP intensity change over time. A simulation using a one-dimensional random walk for the electron hopping in the host material successfully reproduces the PP decay curve.

Enhancement of dissipated energy by large bending of an organic single crystal undergoing twinning deformation.

We demonstrate exceptional twinning deformation in a molecular crystal upon application of mechanical stress. Crystal integrity is preserved and the deformation is associated with a large bending angle (65.44°).

The Effect of Solvent and Coordination Environment of Metal Source on the Self-Assembly Pathway of a Pd(II)-Mediated Coordination Capsule.

The effect of reaction environment on the self-assembly process of an octahedron-shaped PdL capsule was investigated. Quantitative analysis of self-assembly process with H NMR spectroscopy revealed that the self-assembly pathway of the capsule was altered by solvent and a leaving ligand coordinating to the metal source, which are not the components of the final self-assembly. Solvents definitively determine the pathway of the self-assembly at a very early stage of the self-assembly.

DFL2, a new member of the Arabidopsis GH3 gene family, is involved in red light-specific hypocotyl elongation.

A new GH3-related gene, designated DFL2, causes a short hypocotyl phenotype when overexpressed under red and blue light and a long hypocotyl when antisensed under red light conditions. Higher expression of this gene was observed in continuous white, blue and far-red light but the expression level was low in red light and darkness. DFL2 gene expression was induced transiently with red light pulse treatment.