Aromaticity on the pancake-bonded dimer of neutral phenalenyl radical as studied by MS and NMR spectroscopies and NICS analysis

We have demonstrated the first MS and NMR observation of a face-to-face pi-bonded dimer of an organic radical (pancake-bonded dimer coined by R. S. Mulliken) in solution, using tri-tert-butylated phenalenyl radical 1, a 3-fold symmetric neutral hydrocarbon. In addition to the direct detection of the dimer signal by cold-spray ionization mass spectrometry (CSI-MS), 1H and 13C NMR spectra in solution gave definitive evidence of a well-defined D3d dimer structure with a 12-center-2-electron-long C-C bond formation, which is the same symmetry as seen in the crystalline state. On the basis of the NMR peaks of the dimer in the aromatic region (6.47 ppm for 1H NMR and 120-143 ppm for 13C NMR), we carried out nucleus-independent chemical shift (NICS) analysis, which showed that the ring center of the dimer became more aromatic (-7.1 ppm) than that of the monomer (-3.8 ppm). The trend of aromaticity generation was more pronounced in the interior of the dimer, which has been interpreted by the negative electron density induced in the bonding region as seen in the electrostatic potential surface.     

Desulfurization of N,N-dimethylthioformamide by hydrosilane with the help of an iron complex. Isolation and characterization of an iron-carbene complex as an intermediate of C=double bond cleavage

Desulfurization of N,N-dimethylthioformamide (Me(2)NCHS) by hydrosilane has been achieved under photo irradiation in the presence of a methyl iron complex. The reaction sequences have been proposed, in which silyl migration from Fe to S of thioformamide triggers the cleavage of a C=S bond to give a carbene-iron complex. This intermediate was isolated and characterized by X-ray analysis.     

Relationship between diffusivity of water molecules inside hydrating tablets and their drug release behavior elucidated by magnetic resonance imaging

We reported previously that sustained release matrix tablets showed zero-order drug release without being affected by pH change. To understand drug release mechanisms more fully, we monitored the swelling and erosion of hydrating tablets using magnetic resonance imaging (MRI). Three different types of tablets comprised of polyion complex-forming materials and a hydroxypropyl methylcellulose (HPMC) were used. Proton density- and diffusion-weighted images of the hydrating tablets were acquired at intervals. Furthermore, apparent self-diffusion coefficient maps were generated from diffusion-weighted imaging to evaluate the state of hydrating tablets. Our findings indicated that water penetration into polyion complex tablets was faster than that into HPMC matrix tablets. In polyion complex tablets, water molecules were dispersed homogeneously and their diffusivity was relatively high, whereas in HPMC matrix tablets, water molecule movement was tightly restricted within the gel. An optimal tablet formulation determined in a previous study had water molecule penetration and diffusivity properties that appeared intermediate to those of polyion complex and HPMC matrix tablets; water molecules were capable of penetrating throughout the tablets and relatively high diffusivity was similar to that in the polyion complex tablet, whereas like the HPMC matrix tablet, it was well swollen. This study succeeded in characterizing the tablet hydration process. MRI provides profound insight into the state of water molecules in hydrating tablets; thus, it is a useful tool for understanding drug release mechanisms at a molecular level.     

Novel method for constructing a large-scale design space in lubrication process by using bayesian estimation based on the reliability of a scale-up rule

A reliable large-scale design space was constructed by integrating the reliability of a scale-up rule into the Bayesian estimation without enforcing a large-scale design of experiments (DoE). A small-scale DoE was conducted using various Froude numbers (X(1)) and blending times (X(2)) in the lubricant blending process for theophylline tablets. The response surfaces, design space, and their reliability of the compression rate of the powder mixture (Y(1)), tablet hardness (Y(2)), and dissolution rate (Y(3)) on a small scale were calculated using multivariate spline interpolation, a bootstrap resampling technique, and self-organizing map clustering. A constant Froude number was applied as a scale-up rule. Experiments were conducted at four different small scales with the same Froude number and blending time in order to determine the discrepancies in the response variables between the scales so as to indicate the reliability of the scale-up rule. Three experiments under an optimal condition and two experiments under other conditions were performed on a large scale. The response surfaces on the small scale were corrected to those on the large scale by Bayesian estimation using the large-scale results and the reliability of the scale-up rule. Large-scale experiments performed under three additional sets of conditions showed that the corrected design space was more reliable than the small-scale design space even when there was some discrepancy in the pharmaceutical quality between the manufacturing scales. This approach is useful for setting up a design space in pharmaceutical development when a DoE cannot be performed at a commercial large manufacturing scale.     

Accurate position detection of targets in noise image

Targets at various positions in a noise image were detected by the optical matched filtering technique. In this case the thermoplastic optical recorder was used as a matched filter recorder. High accuracy of position detection was obtained, i.e. the position error was 2% or less.     

Infrared seed inspection system (IRSIS) on painted car shells

This paper describes a newly-developed automated thermal system for detection of seeds on newly painted car shells. The system’s novel approach is to use thermal emission; previously applied techniques relied on light reflection strategies. The system is described beginning with analytical modeling of the underlying detection theory to verification on a pilot run in an automotive production line. Parker’s flash procedure, using a thermal detector, was performed to extract the thermal properties of inspected panels. New computer logic developed in-house for processing the acquired thermograms is also presented.     

The first x-ray structure determination of a -phosphaethylene: -2-phenyl-1-(2,4,6-tri-t-butylphenyl)phosphaethylene

The sterically protected -phosphaethylene, -2-phenyl-1-(2,4,6-tri-t-butylphenyl)phosphaethylene (1-Z), was analyzed by X-ray crystallography.     

Littlewood-paley operators on the generalized Lipschitz spaces

Littlewood-Paley operators defined on a new kind of generalized Lipschitz spaces ₀ ^,p are studied. It is proved that the image of a function under the action of these operators is either equal to infinity almost everywhere or is in ₀ ^,p , where –n<<1 and 1<p<.