一國 伸之

Here, an unprecedented phenomenon in which 7-coordinate lanthanide metallomesogens, which align via hydrogen bonds mediated by coordinated H2O molecules, form micellar cubic mesophases at room temperature, creating body-centered cubic (BCC)-type supramolecular spherical arrays, is reported. The results of experiments and molecular dynamics simulations reveal that spherical assemblies of three complexes surrounded by an amorphous alkyl domain spontaneously align in an energetically stable orientation to form the BCC structure. This phenomenon differs greatly from the conventional self-assembling behavior of 6-coordinated metallomesogens, which form columnar assemblies due to strong intermolecular interactions. Since the magnetic and luminescent properties of different lanthanides vary, adding arbitrary functions to spherical arrays is possible by selecting suitable lanthanides to be used. The method developed in this study using 7-coordinate lanthanide metallomesogens as building blocks is expected to lead to the rational development of micellar cubic mesophases.

Abstract A highly dispersed carbonate‐intercalated Cu²⁺‐Al³⁺ layered double hydroxide (CuAl LDH) was created on an unreactive α‐Al₂O₃ surface (CuAl LDH@α‐Al₂O₃) via a simple coprecipitation method of Cu²⁺ and Al³⁺ under alkaline conditions in the presence of α‐Al₂O₃. A highly reducible CuO nanoparticles was generated, accompanied by the formation of CuAl₂O₄ on the surface of α‐Al₂O₃ (CuAlO@α‐Al₂O₃) after calcination at 1073 K in air, as confirmed by powder X‐ray diffraction (XRD) and Cu K‐edge X‐ray absorption near edge structure (XANES). The structural changes during the progressive heating process were monitored by using in‐situ temperature‐programmed synchrotron XRD (tp‐SXRD). The layered structure of CuAl LDH@α‐Al₂O₃ completely disappeared at 473 K, and CuO or CuAl₂O₄ phases began to appear at 823 K or 1023 K, respectively. Our synthesised CuAlO@α‐Al₂O₃ catalyst was highly active for the acceptorless dehydrogenation of benzylic, aliphatic, or cyclic aliphatic alcohols; the TON based on the amount of Cu increased to 163 from 3.3 of unsupported CuAlO catalyst in 1‐phenylethanol dehydrogenation. The results suggested that Cu⁰ was obtained from the reduction of CuO in the catalyst matrix during the reaction without separate reduction procedure and acted as a catalytically active species.

Various alkylcarboxylate-intercalated layered yttrium hydroxides (Cn-1H2n-1COO-/Y-layered rare-earth hydroxide (LRH), n = 1-10) were synthesised by a simple anion exchange method using Cl-/Y-LRH as a parent material. The anion exchange from Cl- into CH3COO- proceeded rapidly, as confirmed by the time-resolved synchrotron-radiation X-ray diffraction (t-SXRD) analysis. The interlayer distance of Cn-1H2n-1COO-/Y-LRH could be controlled precisely, and the basal spacings calculated from XRD were linearly proportional to the length of alkyl groups. In water solvent, the basal spacing of the CH3COO-/Y-LRH catalyst based on the (00l) plane increased from 1.00 nm under dry conditions to 1.35 nm, and this lifted-up layered structure was generated immediately. By use of the CH3COO-/Y-LRH catalyst, a wide range of substrates were converted into the corresponding alpha,beta-unsaturated nitriles in water via Knoevenagel condensation. Our synthesised heterogeneous catalyst acted as a Bronsted base for this organic transformation, and it was reusable without any loss of its catalytic activity and selectivity.

Pt<italic>_n</italic> subnanoclusters (<italic>n</italic> = 3–9) on a carbon substrate exhibit 1.6–2.2 times higher activity than the standard Pt/C catalysts. EXAFS experiments and DFT calculations show plausible structures and energetics for reaction intermediates in the processes.