Showing papers by "Tetsuro Kusamoto published in 2017"
TL;DR: Precisely tuned functional coordination nanosheet exhibits competent catalytic activity for HER, accompany with drastic electronic property switching by redox treatment.
Abstract: A π-conjugated coordination nanosheet comprising bis(aminothiolato)nickel (NiAT) moieties was synthesized by the reaction of Ni(acac)2 with 1,3,5-triaminobenzene-2,4,6-trithiol at liquid-liquid and gas-liquid interfaces. The sheet thickness could be controlled down to a single layer (0.6 nm). Selected area electron diffraction and grazing incidence X-ray diffraction analyses indicated the formation of a flat crystalline sheet with a kagome lattice stacked in a staggered alignment. NiAT was reversibly interconverted to a bis(iminothiolato)nickel (NiIT) nanosheet by the chemical 2H+-2e- reaction, which was accompanied by a drastic change in electrical conductivity from 3 × 10-6 to 1 × 10-1 S cm-1. This change in conductivity was explained by the difference in band structures between NiAT and NiIT. NiAT acted as an efficient electrocatalyst for the hydrogen evolution reaction, showing strong acid durability and an onset overpotential of -0.15 V.
103 citations
TL;DR: In this paper, a π-conjugated coordination nanosheet (CONASH) comprising bis(iminothiolato)nickel moieties, NiIT, was synthesized by a reaction of Ni2+ with 1,3,5-triaminobenzene-2,4,6-trithiol (L) in the presence of ferrocenium ions.
Abstract: A π-conjugated coordination nanosheet (CONASH) comprising bis(iminothiolato)nickel moieties, NiIT, was synthesized by a reaction of Ni2+ with 1,3,5-triaminobenzene-2,4,6-trithiol (L) in the presence of ferrocenium ions. A bulk material, bulk-NiIT, prepared in a homogeneous solution was characterized by XPS, IR, and SEM. A liquid–liquid interfacial reaction using bis(2,4-pentanedionato)nickel(II) in CH2Cl2 and L in H2O afforded a semiconducting nanosheet, nano-NiIT. AFM, SEM, and TEM observation of nano-NiIT revealed the uniform and flat nature of a stacked layer nanosheet. Selected-area electron diffraction (SAED) analysis indicated the formation of a two-dimensional hexagonal crystal structure.
43 citations
TL;DR: The present study revealed that a coordination bond is available for forming emissive CT excited states that lead to high ϕem, providing a novel method with greater capability for realizing highly emissives radicals.
Abstract: A paramagnetic, luminescent organometallic gold(I) complex AuI(C6F5)(PyBTM), where PyBTM is a photostable fluorescent polychlorinated diphenyl(4-pyridyl)methyl radical, was prepared, and its crystal and electronic structures and magnetic and optical properties were investigated. Magnetic studies using electron spin resonance spectroscopy and a superconducting quantum interference device magnetometer indicated the existence of S = 1/2 spin per molecule, with the spin density distributed mainly on the PyBTM ligand. The complex exhibited fluorescence in CHCl3 with emission peak wavelength (λem) of 619 nm and the absolute fluorescence quantum yield (ϕem) of 0.04, confirming that AuI(C6F5)(PyBTM) is the first luminescent organometallic complex with a coordinated luminescent radical. Solvent-dependent unique luminescent characteristics were observed in halogenated solvents (CCl4, CHCl3, CH2Cl2, and ClCH2CH2Cl). ϕem decreased, and λem shifted to longer wavelengths as the polarity (dielectric constant) of the sol...
16 citations
TL;DR: In this paper, a two-dimensional cation-anion supramolecular structure via sulfur's σ-holes was constructed in a functional molecular crystal, (ethyl-4-bromothiazolium)2[Pt(mnt)2]3 (mnt = maleonitriledithiolato).
Abstract: This study reveals that noncovalent intermolecular interactions mediated by σ-holes on sulfur atoms can function as an efficient tool to design and construct a novel supramolecular motif, and that these noncovalent bonds are rigid enough to regulate the displacement of molecules at the structural transition. A novel two-dimensional cation···anion supramolecular structure via sulfur’s σ-holes was constructed in a functional molecular crystal, (ethyl-4-bromothiazolium)2[Pt(mnt)2]3 (mnt = maleonitriledithiolato). The unit cell contained two crystallographically independent anions A and B. Electrostatic σ-hole bonds were detected between σ-holes on sulfur in the cation and lone pairs of −CN moieties in B, while A did not form such S···N σ-hole bonds. This salt exhibited a structural transition at ca. 150 K, in which B did not show apparent displacement, while A shifted along the anion’s stacking direction. This shift enhanced trimerization of the anion in the low-temperature phase, leading to the enhanced ant...
10 citations