Constant infusion system of 15O labeled-water

The quantitative measurement of regional blood flow and regional extravascular lung water, called for a design of 15O labeled water production and administration under continuous and constant flow. In our search for simple methodology, suitable for clinical routine facilities, two remote-controlled systems were designed and their applicability for continuous and constant infusion of H215O were tested. In system (A), H215O was prepared from C15O2 based on the fast exchange reaction between carbon dioxide and carbonic acid. In the system (B), the reaction of 15O2 with H2 using palladium as a catalyst was adopted. In the both systems, the radioactivity level of the infusate was kept constant by using a buffer reservoir. Clinical applicability of both fully automated systems for the production of sterile H215O at a continuous and constant rate was discussed. Namely, system (A), being very simple seems more suitable for any closely located facility but system (B) is more suited for the production of higher radioactivity.     

Enantiodivergent Chemoenzymatic Dynamic Kinetic Resolution: Conversion of Racemic Propargyl Alcohols into Both Enantiomers

Natural lipases typically recognize enantiomers of alcohols based on the size differences of substituents near the carbinol moiety and selectively react with the R enantiomers of secondary alcohols. Therefore, lipase-catalyzed dynamic kinetic resolution (DKR) of racemic secondary alcohols produces only R enantiomers. We report herein a method for obtaining S enantiomers by DKR of secondary 3-(trialkylsilyl)propargyl alcohols by using a well-known R-selective Pseudomonas fluorescens lipase in combination with a racemization catalyst VMPS4, in which the silyl group reverses the size relationship of substituents near the carbinol moiety. We have already reported R-selective DKR of the corresponding propargyl alcohols without substituents on the ethynyl terminal carbon, and the presence of an easily removable silyl group has enabled us to produce both enantiomers of propargyl alcohols in high chemical yields and with high enantiomeric excess. In addition, immobilization of the lipase on Celite was found to be important for achieving a high efficiency of the DKR.     

Chemically Laminated 2D Bis(terpyridine)metal Polymer Films: Formation Mechanism at the Liquid–Liquid Interface and Redox Rectification

Recent studies on molecular 2D materials with high tunability of structure and function have focused mostly on the discovery of new precursors. Here, we demonstrate a facile one-pot synthesis of laminated 2D coordination polymer films comprising bis(terpyridine)iron and cobalt at a water/dichloromethane interface. Cross-sectional elemental mapping unveiled the stratum-like structure of the film and revealed that the second layer grows to the dichloromethane side below the first layer. Cyclic voltammetry clarified that the bottom layer mediates charge transfer between the top layer and the substrate in a narrow potential region of mixed-valence states. Furthermore, the bilayer film sandwiched by electrodes in a dry condition shows stable rectification character, and the barrier voltage corresponds to the redox potential difference between the two layers. This study introduces a new strategy for polymer design to explore the materials science of molecular 2D materials.     

Integrated palladium-catalyzed arylation of heavier Group 14 hydrides

A convenient procedure has been developed for the preparation of Group 14 compounds by integrated palladium-catalyzed cross-coupling of aromatic iodides with the corresponding Group 14 hydrides in the presence of a base. The reaction conditions can be applied to the cross-coupling of tertiary, secondary, and primary Group 14 compounds. In most cases, the desired arylated products were obtained in synthetically useful yields. Even in the case of aryl iodides containing OH, NH(2), CN, or CO(2)R groups, the reactions proceeded with good to high yields with tolerance of these reactive functional groups. A possible application of this method is the unique synthesis of a fungicidal diarylmethyl(1H-1,2,4-triazol-1-ylmethyl)silane derivative.     

Synthesis,characterization, and crystal structures of two novel ion-pair complexes based on benzene-1,2-dithiolate ligand

Two novel ion-pair complexes, [IBzPy][Ni(Bdt)₂] (I) and [IBzDMPy][Ni(Bdt)₂] (II) (IBzPy = 1-(4-iodobenzyl)pyridinium, IBzDMPy = 1-(4-iodobenzyl)-3,5-dimethyl-pyridinium, and Bdt = benzene-1,2-dithiolate), have been synthesized and characterized by elemental analysis, IR, cyclic voltammetry, and X-ray single-crystal structure determination. The crystal structure determination reveals that the central Ni atoms in complexes I and II are in slightly distorted square-planar coordination environment. The cyclic voltammetric studies show that there are two oxidation peaks for complexes I and II, which are attributed to Ni(IV/III) and Ni(III/II) redox couples.