Yoji Kobayashi 교수

The new microporous metal−organic framework Cu[Ni(pdt)2] (pdt2− = pyrazine-2,3-dithiolate) is demonstrated to have an optical bandgap, p-type semiconductivity, and redox activity. The compound can be doped by using I2 as an oxidant, leading to an increase in conductivity by 4 orders of magnitude with retention of porosity.

The problem of activating N₂ and its subsequent hydrogenation to form NH₃ has been approached from many directions. One of these approaches involves the use of transition metal hydride complexes. Recently, transition metal hydride complexes of Ti and Ta have been shown to activate N₂, but without catalytic formation of NH₃. Here, we show that at elevated temperatures (400 °C, 5 MPa), solid-state hydride-containing Ti compounds (TiH₂ and BaTi

The nanoscroll-to-nanotube thermal transformation was studied for H4Nb6O17·4.4H2O scrolls, prepared by exfoliation of K4Nb6O17. Thermal dehydration of the scrolls produces Nb2O5 nanotubes at 400−450 °C. The nontopochemical transformation results in polycrystalline nanotubes; however, significant texturing with respect to the tube axis is observed. Substituting Ta for Nb in the precursor compound led to a lower yield of scrolls, most likely because there is less built-in lattice strain to drive s

Cation-exchangeable d(0) layered perovskites are amenable to intercalation, exfoliation, and a variety of topochemical reactions, but they lack the interesting electronic and magnetic functionalities of mixed-valent perovskites. Conversely, electronically and magnetically interesting layered perovskites lack scope in terms of interlayer chemistry. To bridge this gap, the insulating, cation-exchangeable layered perovskites RbLaNb(2)O(7), KCa(2)Nb(3)O(10), and NaYTiO(4) were reacted with poly(tetr

We report the synthesis of a wide range of single-crystal spinel platelets with exposed (111) faces, lateral dimensions in the micrometer range, and thicknesses of 20–50 nm, prepared by soft chemical dehydration of well crystallized layered precursors. This method enables the synthesis of the metastable composition NiCoAlO4, which cannot be prepared by conventional solid state synthesis. Because of their nanoscale thickness, mosaic structure, shape anisotropy, and surface porosity, NiCoAlO4 and

In this review we describe recent advances in transition metal oxyhydride chemistry obtained by topochemical routes, such as low temperature reduction with metal hydrides, or high-pressure solid-state reactions. Besides the crystal chemistry, magnetic and transport properties of the bulk powder and epitaxial thin film samples, the remarkable lability of the hydride anion is particularly highlighted as a new strategy to discover unprecedented mixed anion materials.

Perovskite-type oxides have proven to be a versatile class of compounds with systematic study of their structure and various properties. Further structural variations and properties can be added by adding a second anionic species other than oxide, such as hydride, fluoride, nitride, or others. The different charge, covalency, size, and new modes of local coordination offer convenient ways to further control carrier doping, magnetism, conductivity, and even chemical reactivity. In this review we