Studies on the magnetic ground state of a spin Möbius strip

Here we report the synthesis, structure and detailed characterisation of three n-membered oxovanadium rings, Nan[(V=O)nNan(H2O)n(α, β, or γ-CD)2]⋅mH2O (n = 6, 7, or 8), prepared by the reactions of (V=O)SO4⋅xH2O with α, β, or γ-cyclodextrins(CDs) and NaOH in water. Their alternating heterometallic vanadium/sodium cyclic core structures were sandwiched between two CD moieties such that O-Na-O groups separated neighbouring vanadyl ions. Antiferromagnetic interactions between the S = ½ vanadyl ions led to S = 0 ground states for the even-membered rings, but to two quasi-degenerate S = ½ states for the spin-frustrated heptanuclear cluster

A Case of Mycobacterial Skin Disease Caused by Mycobacterium peregrinum, and a Review of Cutaneous Infection

An 83-year-old Japanese man presented with a 2-month history of symptomatic nodules on the left hand. He was not in an immunocompromised condition and reported no causal events. A biopsy specimen demonstrated granulomatous tissue with mixed cell infiltration consisting of neutrophils, histiocytes, lymphocytes, and multinuclear giant cells. No bacillus was detected by PAS, acid-fast stain, immunofluorescent stain or polymerase chain reaction analysis. The isolate was found to be a rapidly growing mycobacterium after 4 weeks of incubation at 25°C on an Ogawa egg slant. Mycobacterium peregrinum was isolated by DNA-DNA hybridization analysis, 16S rRNA gene sequence, and by its production of 3-day arylsulfatase. The patient received 200 mg oral minocycline for 28 weeks. The lesion disappeared after 10 weeks of this treatment

An antiferromagnetically coupled heterometal Cu6Fe wheel

A heterometal Cu6Fe wheel molecule, [CuII6FeIII(HL)6- (OH)2(OCH3)4](NO3)3¢6H2O (1¢6H2O) (H2L = 1-(2-pyridine) 3-(2-pyrrole)acetylacetone) was synthesized by the one-pot reaction of H2L with copper and iron sources. X-ray structural analysis reveals that the heptanuclear wheel cluster consists of a central Fe(III) ion surrounded by six Cu(II) ions, linked through methoxo- and hydroxo-bridges. Cryomagnetic studies indicate intramolecular antiferromagnetic interactions were operative

Calcitonin Receptor Signaling Inhibits Muscle Stem Cells from Escaping the Quiescent State and the Niche

Masahiko Yamaguchi, Yoko Watanabe, Takuji Ohtani, Akiyoshi Uezumi, Norihisa Mikami, Miki Nakamura, Takahiko Sato, Masahito Ikawa, Mikio Hoshino, Kunihiro Tsuchida, Yuko Miyagoe-Suzuki, Kazutake Tsujikawa, Shin’ichi Takeda, Hiroshi Yamamoto, So-ichiro Fukada, Calcitonin Receptor Signaling Inhibits Muscle Stem Cells from Escaping the Quiescent State and the Niche, Cell Reports, Volume 13, Issue 2, 2015, Pages 302-314, ISSN 2211-1247, https://doi.org/10.1016/j.celrep.2015.08.083

Crystal structure of bis(tetraphenylphosphonium) bis(cyanido-κC)(29H,31H-tetrabenzo[b,g,l,q]porphinato-κ4N29,N30,N31,N32)ferrate(II) acetone disolvate

The crystal structure of the title compound, (C24H20P)2[Fe(C36H20N4)(CN)2]·2C3H6O, is constructed from a tetrahedral Ph4P+ (tetraphenylphosphonium) cation, one [Fe(tbp)(CN)2]2− anion (tbp = tetrabenzoporphyrin in its doubly deprotonated form), located on a centre of inversion, and an acetone molecule as crystallization solvent. Since the molecular structure of the M(tbp) moiety is insensitive to the kind of metal ion and its oxidation state, bond lengths and angles in the [Fe(tbp)(CN)2]2− anion are similar to those in other M(tbp) compounds. The Fe2+ ion, located on a centre of inversion, is coordinated by four N atoms of tpb in the equatorial plane and by two C atoms of the cyanide anion at axial positions in a slightly distorted octahedral configuration. The packing is stabilized by C—H...N interactions between the Ph4P+ cation and the CN− ligand of the [Fe(tbp)(CN)2]2− anion, and by C—H...π interactions between the Ph4P+ cation, acetone solvent molecules and the [Fe(tbp)(CN)2]2− anion

N-Type Semiconducting Behavior of Copper Octafluorophthalocyanine in an Organic Field-Effect Transistor

Based on the crystal structure analysis, the overlap integral between the frontier molecular orbitals of adjacent F8CuPcs in the one-dimensional chain is estimated: the overlap integral between the lowest unoccupied molecular orbitals is 5.4 × 10−3, which is larger than that in a typical n-type semiconducing material F16CuPc (2.1 × 10−3), whereas that between the highest occupied molecular orbitals is 2.9 × 10−4. Contrary to previous studies in air, we found that an organic field-effect transistor (OFET) composed of F8CuPc essentially shows clear n-type semiconducting behavior in vacuum

Molecular motion in pyridazinium/crown ether supramolecular cation salts of a nickel dithiolene complex

Supramolecular cations formed by monoprotonated pyridazinium cations and cis-anti-cis-dicyclohexano[18]-crown-6 (DCH[18]-crown-6) or dibenzo[18]-crown-6 (DB[18]-crown-6) were introduced into [Ni(dmit)2]- salts (where dmit^[2-] = 2-thione-1,3-dithiole-4,5-dithiolate). X-ray crystal structure analysis of (pyridazinium+)(DCH[18]-crown-6)[Ni(dmit)2]- (1) revealed a chair-type conformation of the DCH[18]-crown-6 moiety. A V-shaped conformation of the DB[18]-crown-6 moiety was observed in (pyridazinium+)(DB[18]-crown-6)2[Ni(dmit)2]-(H2O)2 (2). Nitrogen atoms in the pyridazinium cations interacted with the oxygen atoms of the DCH[18]-crown-6 and DB[18]-crown-6 through N-H+～O hydrogen bonds, forming 1 : 1 and 1 : 2 supramolecular structures, respectively. Sufficient space for molecular motions of the pyridazinium cations, namely flip-flop and in-plane rotations, exists in salt 1. Disorder in nitrogen atoms was observed by X-ray analysis, indicating dynamic motion of the pyridazinium cation, namely flip-flop motion and in-plane motion. A potential energy calculation further supported the possibility of dynamic motion of cations in the crystal. By contrast, the flip-flop motion of the pyridazinium group in salt 2 is restricted by the two nearest-neighbouring DB[18]-crown-6 molecules. Weak antiferromagnetic intermolecular interactions between the [Ni(dmit)2]- anions in the two-dimensional layers of salt 1 were observed, resulting in alternating antiferromagnetic Heisenberg chain-type magnetic susceptibility. Quasi-one-dimensional intermolecular interactions between the [Ni(dmit)2]- anions were observed in salt 2, whose magnetic behaviour followed the Bonner-Fisher model