Electrochemical Small-Angle X-ray Scattering for Potential-Dependent Structural Analysis of Redox Enzymes.

Various methods exist for exploring different aspects of these mechanisms. However, techniques for investigating structural differences between the reduced and oxidized forms of an enzyme are limited. Here, we propose electrochemical small-angle X-ray scattering (EC-SAXS) as a novel method for potential-dependent structural analysis of redox enzymes and redox-active proteins.

Structure of Polymer-Grafted Nanocellulose in the Colloidal Dispersion System.

Clarifying the primary structure of nanomaterials is invaluable to understand how the nanostructures lead to macroscopic material functions. Nanocellulose is attracting attention as a sustainable building block in materials science. The surface of nanocellulose is often chemically modified by polymer grafting to tune the material properties, such as the viscoelastic properties in rheology modifiers and the reinforcement effect in composites.

Photoluminescent Ferroelastic Molecular Crystals.

Ferroelasticity has been reported for several types of molecular crystals, which show mechanical-stress-induced shape change under twinning and/or spontaneous formation of strain. Aiming to create materials that exhibit both ferroelasticity and light-emission characteristics, we discovered the first examples of ferroelastic luminescent organometallic crystals. Crystals of arylgold(I)(N-heterocyclic carbene)(NHC) complexes bend upon exposure to anisotropic mechanical stress.

A Multidirectional Superelastic Organic Crystal by Versatile Ferroelastical Manipulation.

Mechanical twinning changes atomic, molecular, and crystal orientations along with directions of the anisotropic properties of the crystalline materials while maintaining single crystallinity in each domain. However, such deformability has been less studied in brittle organic crystals despite their remarkable anisotropic functions. Herein we demonstrate a direction-dependent mechanical twinning that shows superelasticity in one direction and ferroelasticity in two other directions in a single crystal of 1,3-bis(4-methoxyphenyl)urea.

Superplasticity in an organic crystal.

Superplasticity, which enables processing on hard-to-work solids, has been recognized only in metallic solids. While metallic materials and plastics (polymer solids) essentially possess high plastic workability, functional crystalline solids present difficulties in molding. Organic crystals especially are fragile, in the common view, and they are far from the stage of materials development.

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°).

Studies on Aculeines: Synthetic Strategy to the Fully Protected Protoaculeine B, the N-Terminal Amino Acid of Aculeine B.

A synthetic strategy for accessing protoaculeine B (1), the N-terminal amino acid of the highly modified peptide toxin aculeine, was developed via the synthesis of the fully protected natural homologue of 1 with a 12-mer poly(propanediamine). The synthesis of mono(propanediamine) analog 2, as well as core amino acid 3, was demonstrated by this strategy. New amino acid 3 induced convulsions in mice; however, compound 2 showed no such activity.

Twinning ferroelasticity facilitated by the partial flipping of phenyl rings in single crystals of 4,4'-dicarboxydiphenyl ether.

Evidence of ferroelasticity in a non-planar organic molecular crystal is presented for 4,4'-dicarboxydiphenyl ether. Ferroelasticity has been demonstrated by the micro- and macroscopic mechanical characterization of single crystals, including recording of a full hysteretic stress-strain cycle. The underlying mechanism involves the partial flipping of phenyl rings.

An organoferroelasticity driven by molecular conformational change.

A single crystal of adipic acid shows twinning ferroelasticity by the reversible molecular conformational change. The flexible nature of components in molecular solids raises the efficiency of energy dissipation using organoferroelasticity.

Ferroelasticity in an Organic Crystal: A Macroscopic and Molecular Level Study.

Ferroelasticity has been relatively well-studied in mechanically robust inorganic atomic solids but poorly investigated in organic crystals, which are typically inherently fragile. The absence of precise methods for the mechanical analysis of small crystals has, no doubt, impeded research on organic ferroelasticity. The first example of ferroelasticity in an organic molecular crystal of 5-chloro-2-nitroaniline is presented, with thorough characterization by macro- and microscopic methods.

Shape-memory effect in an organosuperelastic crystal.

Shape-memory materials, , polymers (SMPs: shape-memory polymers) and alloys (SMAs: shape-memory alloys), have been developed in very different ways since they are historically far apart in material type as well as physical property. In the deformation process, SMPs require only a slight stress due to the properties of organic polymer solids, and they reveal a smaller recovery force during the thermoplastic process whereas SMAs require a relatively large stress due to metallic properties, and they thermally tighten to generate a larger recovery force destabilization of the stress-induced phase. An investigation into the unexplored area of the material adjoining both ends of SMPs and SMAs would lead toward a better understanding of shape-memory materials and extend future applications and material types.

Active porous transition towards spatiotemporal control of molecular flow in a crystal membrane.

Fluidic control is an essential technology widely found in processes such as flood control in land irrigation and cell metabolism in biological tissues. In any fluidic control system, valve function is the key mechanism used to actively regulate flow and miniaturization of fluidic regulation with precise workability will be particularly vital in the development of microfluidic control. The concept of crystal engineering is alternative to processing technology in microstructure construction, as the ultimate microfluidic devices must provide molecular level control.

Superelastic shape recovery of mechanically twinned 3,5-difluorobenzoic acid crystals.

Generally, superelastic behavior cannot be expected in mechanically twinned crystals because there is essentially no strain on the interface that is a driving force for spontaneous shape recovery. However, we found that single crystals of 3,5-difluorobenzoic acid are superelastic organic crystals under mechanical twinning. The unexpected shape recovery can be explained by molecular distortion on the twinning interface, which suggests a new mechanism for superelasticity in molecular materials.

Reversible crystal deformation of a single-crystal host of copper(II) 1-naphthoate-pyrazine through crystal phase transition induced by methanol vapor sorption.

A novel microporous single crystal of [Cu(II)2(1-NA)4(pyz)]n (1-NA: 1-naphthoate, pyz: pyrazine) exhibited bending and straightening action on a macroscopic scale during the first-order crystal phase transition induced by methanol vapor sorption.

Gas permeation in a molecular crystal and space expansion.

A novel single-crystal membrane [Cu(II)2(4-F-bza)4(2-mpyz)]n (4-F-bza = 4-fluorobenzoate; 2-mpyz = 2-methylpyrazine) was synthesized and its identical permeability in any crystal direction in the correction for tortuosity proved that gas diffuses inside the channels without detour. H2 permeated by 1.18 × 10(-12) mol m m(-2) s(-1) Pa(-1) with a high selectivity (Fα: 23.

A preferable molecular crystal membrane for H₂ gas separation.

A novel molecular crystal membrane [Cu(II)2(9-AC)4(pyz)]n (9-AC: 9-anthracenecarboxylate, pyz: pyrazine) shows high permselectivity for H2/CO (79.0), H2/CH4 (137), and H2/CO2 (12.1) due to the high rate of H2 permeation (3820 Barrer) while inhibiting the permeation of such a large gaseous particle even in its wider channel than the Lennard-Jones diameter of each gas.

Single-crystal membrane for anisotropic and efficient gas permeation.

Development of gas separation materials has been one of the basic requirements of industry. Microporous materials have adequate pores for gas separation and have contributed to the advancement of gas purification techniques. Because the simplest and most economical method would be membrane separation, various microporous membranes have been prepared and explored for their separation properties.

Host-guest transformational correlations for a gas inclusion co-crystal on changing gas pressure and temperature.

The CO(2) adsorption behavior and inclusion structure of a flexible single-crystal host [Cu(2)(bza)(4)(pyz)](n) were studied under various conditions (203-373 K, <15.4 MPa) and the correlation between changes in gas adsorption behavior and the structures of guest arrangement and host component packing were investigated.