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Ethyl L-sorboside, C8H16O6, was prepared from the rare sugar L-sorbose, C6H12O6, and crystallized. It was confirmed that ethyl L-sorboside formed α-pyranose with a 2 C 5 conformation. In the crystal, molecules are linked by O—H...O hydrogen bonds, forming a three-dimensional network. The unit-cell volume of the title ethyl α-L-sorboside is 940.63 Å3 (Z = 4), which is about 194.69 Å3 (26.1%) bigger than that of L-sorbose [745.94 Å3 (Z = 4)].

Pseudomonas cichorii D-tagatose 3-epimerase (PcDTE), which has a broad substrate specificity, efficiently catalyzes the epimerization of not only D-tagatose to D-sorbose but also D-fructose to D-psicose (D-allulose) and also recognizes the deoxy sugars as substrates. In an attempt to elucidate the substrate recognition and catalytic reaction mechanisms of PcDTE for deoxy sugars, the X-ray structures of the PcDTE mutant form with the replacement of Cys66 by Ser (PcDTE_C66S) in complexes with deoxy sugars were determined. These X-ray structures showed that substrate recognition by the enzyme at the 1-, 2-, and 3-positions is responsible for enzymatic activity and that substrate-enzyme interactions at the 4-, 5-, and 6-positions are not essential for the catalytic reaction of the enzyme leading to the broad substrate specificity of PcDTE. They also showed that the epimerization site of 1-deoxy 3-keto D-galactitol is shifted from C3 to C4 and that 1-deoxy sugars may bind to the catalytic site in the inhibitor-binding mode. The hydrophobic groove that acts as an accessible surface for substrate binding is formed through the dimerization of PcDTE. In PcDTE_C66S/deoxy sugar complex structures, bound ligand molecules in both the linear and ring forms were detected in the hydrophobic groove, while bound ligand molecules in the catalytic site were in the linear form. This result suggests that the sugar-ring opening of a substrate may occur in the hydrophobic groove and also that the narrow channel of the passageway to the catalytic site allows a substrate in the linear form to pass through.

Metal complex indicates the significant physical properties such as magnetism, electrical conductivity and an optical property due to the electronic interaction between the ligand molecule and the central metal ion. We have evaluated the magnetism of the metal complex by controlling the ligand field splitting, which is the energy splitting of the d-orbitals. The magnetic phenomenon of such compounds are realized as a result of the electronic state based on the transition metal coordination complexes, and which can be switched between high spin (HS) and low spin (LS), that is called a spin-crossover (SCO) phenomenon. Our group have been investigated the way how to control the spin state according to the concept of a molecular distortion. The five-coordinated metal complex ML5 has been experimentally confirmed to be a molecular distortion called the Berry pseudorotation (BPR). In the BPR process, both the axial and equatorial ligands can move at the same rate of increasing the angle between the other axial or equatorial ligands in five-coordinated metal complex. The classical BPR mechanism changes its molecular symmetry between two independent trigonal bipyramidals (TBPs) of D3h symmetry via a square pyramidal (SP) of C4v symmetry. The distortion parameters in the five-coordinated metal complexes τ5 are proposed in order to represent the distortion of the BPR process quantitatively. In this work, we predicted the possibility of the SCO phenomenon in intramolecular exchange mechanism through the BPR process in a five-coordinated metal complexes.

Considering our lives, novel energy production is so required, and many scientists have been investigated this problem from a lot of views. One of the ways for the new energy productions is the solar power thermochemical production by an oxidation-reduction reaction of the ceramics CeO2 (ceria). In this research, the ceria is used for obtaining an H2 gas in vapor reaction in high-temperature thermal equipment which has a heat production system consisting by focused sun light. Nowadays technology has been also developed to keep a human living, not to harm the Earth environment. From these points, it is realized that how important the H2 gas is for our lives, so we are trying to improve the thermochemical H2 gas production by means of a ceria as a catalyst. Our purpose in this study is, to point out what effects occur in doped ceria’s thermal reduction (TR) reaction by using DV-Xα method. Comparing the models between the pure ceria and the Mn doped ceria, we have realized the difference by the reaction. In this appearance, one of the considerations is a view from p-DOSs (partial-Density of States), in which there are different O-2p DOSs by different crystal structures. From this view, we considered that the ceria structure would become more stable to keep the stable cyclic thermal reaction in Mn doped ceria.

We introduce a superatom, which is regarded as a modern alchemy and has been studied around the world. The superatom is a nanocluster composed of multiple atoms, for example Al13. Very interestingly, the “superatom” can mimic the chemical properties of “atom”, for example, the superatom Al13 exhibits the character of halogen atom, such as Cl. If this superatom is synthesized to an appropriate size freely, there is the possibility to be placed as an “artificial atom” in a three-dimensional periodic table, such as the conventional two-dimensional periodic table. In recent years, the exhaustion of rare metals has become a big problem, so that in the next generation of materials and devices, the superatom play as an important role, and it is expected to be used for various materials or as a substitute for expensive metal catalysts such as Pt. From these points of view, the superatom have been studied all over the world up to now, but there is not much studies on their electronic structures. Therefore, in this study, we have analyzed the electronic states of the chalcogen-encapsulated type superatom M@Al12 (M = Be, Mg, Ca, Sr) by means of DV-Xα molecular orbital calculation. Our research revealed that the electronic configuration of the superatom, which changed only the central atom, depends largely on the kind of doped atom. And we can also confirm the “superatomic hybrid orbitals (SAHOs)” composed of superatomic orbitals (SAOs), and chalcogen characteristics.

Metal complexes exhibit significant physical properties such as electrical conductivity, magnetism and optical properties. They can be controlled by changing the ligand field splitting of the d-orbital of the central metal ion. We have investigated the reversible spin crossover (SCO) phenomenon by changing the ligand field splitting in six-coordinated metal complexes ML6. In this study, we focused on the change of the spin states by uniaxial Jahn-Teller distortion in the case of an octahedral hexa-coordinated metal complexes ML6, involving two types of different ligand molecules. In addition, we have used DV-Xα and DVME methods in order to calculate the electronic states. In order to reproduce the effect of the Jahn-Teller distortion in the calculation, a uniaxial anisotropic distortion has been applied into the octahedral hexa-coordinate metal complex. The purpose of this research is to study the mechanism and phenomenon of the spin state changing by discussing the calculated electronic states of the spin crossover phenomenon.

Rare sugar is a monosaccharide that there are trace amounts in nature, natural sugars present in large amounts in nature world is referred to as a naturally monosaccharide. Recently, the isomerase called D-tagatose-3-epimerase (DTE) was discovered, and it has a possibility to synthesize quantity of the rare sugar from a natural sugar through the enzymatic reaction. And all of hexoses can be synthesized by four kinds of enzymatic reactions (oxidoreductase, aldose isomerase, aldose reductase and DTE reactions). In this study, single-crystal X-ray structure analysis of a sugar alcohol and its derivative have been performed in order to determine the absolute coordinates of these sugar molecules. We have also investigated the electronic state calculation by means of DV-Xα method using the obtained data of the absolute coordinates. We also consider that mechanism of the enzymatic reaction and intermolecular energy properly such as a hydrogen bond in order to synthesize the supramolecular rare sugars (SRSs) which can be controlled structures and the hydrogen bonds.

There are two types of mono-saccharide sugars in nature, which are natural monosaccharide and rare sugar. The sugar that exists in extreme few amount in nature is called as rare sugar e.g. D-psicose and D-allose. The reasons we choose the rare sugar as a research target are because the rare sugar has almost no calories and is very useful for diabetic and dieter patients. Specifically, D-psicose is a no-calorie rare sugar with the sweetness of about 70 % of a sucrose. It has been confirmed that taking the D-psicose with meals suppresses the rise of sugar into the blood. Further, it is very effective in improving and preventing the diabetes. In order to investigate a research on the rare sugars, the first step must be to obtain the correct molecular structure. However, few crystal structures of rare sugars have been reported up to now. Therefore, the purpose of this research is to analyze the single-crystal X-ray structure of unknown rare sugar ‘L-glucose’. In addition, the DV-Xα molecular orbital method is used to compare the differences in a hydrogen bonding between α-D-glucose and α-L-glucose, and to make a novel supramolecular rare sugar.

Because of the chiral nature of the building blocks of living matter, an optical phenomena associated with the chirality constitute an important topic in physical chemistry. The specific optical rotation, which is a parameter for the characterization of the natural optical activity, depends strongly on the conformation of the molecule. In this study, we investigated the dependence of the optical rotation on a molecular conformation in the gas phase by calculating the electronic states of seven kind of chiral amino acids using the DV-Xα method. As a result, we can confirm the existence of an antibonding orbital on the side chain and the optical rotations are strongly related.

We introduce rare sugars including their derivatives and supramolecular rare sugars, that have been actively researched at Kagawa University, Japan. Although the rare sugars are special sugars which hardly exist in nature, we has succeeded in mass synthesis of the rare sugars by utilizing biological enzyme isomerization reaction. In addition, the rare sugars have various functions such as blood sugar level suppressing function, cancer cell growth suppressing function, and antibacterial action. In addition, since rare sugars have a large number of hydroxyl groups, they have a possibility for using as devices for expressing various functions by employing them as ligands of transition metal complexes. In recent years, it is successful that we have synthesized the suplamolecular rare sugars (SRSs) from the different types of rare sugars, that is not as simple mixtures but as single crystals having supralattice structure, that can be freely controlled optical rotation. It has been found that the crystal structures of these SRSs mostly follow the Wallach rule, but do not satisfy the Wallach rule especially in the case of D, L-psicose. Therefore, we have investigated the single crystal X-ray structural analyses of SRSs, obtaining the detailed crystal structure data, and analyzed the intermolecular interaction between their sugar molecules in the crystal by means of the DV-Xα molecular orbital calculation. According to our detailed analysis of the research, calculating the intermolecular interaction revealed that the stability of the intermolecular interaction in the crystal can not be explained only by following the simple Wallach rule. Specifically, for example in the case of D, L-psicose, the total energy in a crystal can be stabilized by aligning the polarization vectors of the molecules, and as a result, we have clarified that the SRSs crystal structure can be stabilized, even if it does not follow the simple Wallach rule.

The racemic title compound, C6H12O6, consisting of C-4 epimers of psicose, was crystallized from an aqueous solution of an equimolar mixture of D- and L-sorboses. It was confirmed that D-sorbose (or L-sorbose) formed α-pyranose with a 4 C 1 (or 1 C 4) conformation where the anomer position was designated as carbon-1. The asymmetric unit comprises two crystallographically independent molecules. In the crystal, molecules are linked by O—H...O hydrogen bonds, forming a three-dimensional framework. The unit-cell volume of the title racemic α-D,L-sorbose is 1450.86 (6) Å3 (Z = 8), which is about 41 Å3 smaller than that of twice the amount of chiral α-L-sorbose [V = 745.942 Å3 (Z = 4)].

The solubility and ice melting point of a binary system containing water and D-allose (D-All), the C3 epimer of D-glucose, were investigated and, for the first time, a binary phase diagram was cons...

A high dye coverage on the TiO2 surface diminishes dye-sensitized solar cell (DSSC) performances because of the significant degree of excited electron and hole recombination that results from the strong dye–dye intermolecular interactions. In this study, interplay between dye coverage and photovoltaic performances of DSSCs was systematically investigated and discussed using adsorption isotherms, photovoltaic measurements, and impedance analyses. Commercially available P25 and laboratory synthesized {010}-faceted TiO2 nanoparticles were used in mesoporous electrodes, and MK-2 organic dye was used as a sensitizer. Estimated adsorption constant (Kad) and maximum adsorption density (Qm) were 1.03 × 105 dm3/mol and 1.39 × 10–6 mol/m2 for P25 and 1.50 × 105 dm3/mol and 8.62 × 10–7 mol/m2 for {010}-faceted TiO2, respectively. The maximum TiO2 surface coverage of about 60% with {010}-faceted TiO2 and near 100% with P25 were observed in adsorption isotherms. I–V characteristics curves showed the continuous enhance...

Nanohybrid solution and thin film of Rhodamine 6G (R6G) or pseudo-isocyanine (PIC) with the titanate nanosheets (HTO) of H1.07Ti1.73O4·nH2O with a lepidocrocite-like layered structure were fabricated by using a soft chemical process. The optical properties of the nanohybrids were investigated by absorption and fluorescence spectroscopies. An H-aggregate of the R6G molecules was formed in the R6G–HTO nanohybrid system, while a J-aggregate of the PIC molecules was formed in the nanohybrid PIC–HTO system. Fluorescence quenching behavior was observed in both of the R6G–HTO and PIC–HTO nanohybrid systems.

The title compound, C6H12O5, was crystallized from an aqueous solution of 6-deoxy-L-psicose (6-deoxy-L-allulose, (3S,4S,5S)-1,3,4,5-tetrahydroxyhexan-2-one), and the molecule was confirmed as α-furanose with a3T4(orE4) conformation, which is a predominant tautomer in solution. This five-membered furanose ring structure is the second example in the field of the 6-deoxy-ketohexose family. The cell volume of the title compound [742.67 (7) Å3,Z= 4 at room temperature] is only 1.4% smaller than that of β-D-psicopyranose, C6H12O6(753.056 Å3,Z= 4 at room temperature).

Uvedafolin, 1, a new sesquiterpene lactone dimer, was isolated from the leaves of Smallanthus sonchifolius with five related compounds, 2-6, and their cytotoxicity was assessed against three tumor cell lines (HeLa, HL-60, B16-F10 melanoma). The stereostructure of 1 was newly elucidated by ESI-TOF-MS, 1D/2D NMR, and single-crystal X-ray diffraction. Dimers 1 and 2 had the most effective IC50 values, 0.2-1.9 μM, against the three tumor cell lines when compared with monomers 3-6 (IC50 values 0.7-9.9 μM) and etoposide (IC50 values 0.8-114 μM). The ester linkages of two sets of monomers, uvedalin, 5, and sonchifolin, 6, for 1, and enhydrin, 4, and sonchifolin, 6, for 2, as well as the acetyl group at the C-9 position, were essential for the high cytotoxicity. Dimers 1 and 2 would have potential as anticancer agents.

X-ray crystal analysis for D-psicose (C3-position epimer of D-fructose) crystallized from aqueous solution was successfully performed for the first time. It was confirmed that D-psicose crystallize...

We have studied a novel universal spectrochemical series of the six-coordinated octahedral 3d transition metal complexes that can be used for any combinations of the central metal atoms and the ligand molecules. The spectrochemical series for the six-coordinated octahedral metal complexes can be well explained by the energy level comparison between the metals and ligands using the DV-Xα method. The two-dimensional spectrochemical series can be applied for expecting of the ligand field splitting energy widths of not only the known compounds but also the unknown ones. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2009

We studied a novel universal spectrochemical series of six-coordinated octahedral 3d transition metal complexes, which can be used for any combination of central metal atom and ligand molecules. A two dimensional spectrochemical series could be used to estimate the ligand field splitting energy of not only known compounds but also the unknown compounds. Therefore, it should be possible to control the physical properties, such as the electronic and magnetic properties and the optical phenomena of octahedral transition metal complexes by modifying the ligand field splitting.

In situ X-ray photoelectron spectra (XPS) of metal–octaethylporphyrin [Pd(OEP), Cu(OEP), and Zn(OEP)] and C60 alternative-deposited films on a silicon substrate are presented for the fabrication of high-performance organic thin-film photovoltaic (PV) cells. XPS results indicated that only Zn(OEP) and C60 alternative-deposited films have a layered structure, whereas the other films have a mixed structure. This may be due to the difference in molecular symmetry between the anti- and syn-configurations of M(OEP): Zn(OEP) has a syn-configuration that can be stacked on a C60 film, whereas the other M(OEP)s have an anti-configuration that is difficult to be stacked on the film.

Nano-modification of highly-oriented pyrolytic graphite (HOPG) surfaces using slow highly-charged ion (HCI) beam irradiation has been demonstrated. Single HCI impact creates nanoscale protrusions in which the electronic structure is different from that formed by singly-charged ion impact. By combining slow HCI irradiation with electron injection onto the impact region, a transition of sp 2 to sp 3 hybridization is obtained, resulting in I – V characteristics of the impact region showing non-conductive properties with ∼ 6 eV band gap. The size of the features created by Ar 8+ -impact on HOPG are about ∼ 1 nm in diameter at 400 eV kinetic energy, which corresponds with a region where electron emission occurs by the Coulomb potential of the HCI. Assuming that 20 carbon atoms are contained in the structure formed, we discuss plausible sp 3 carbon structures by means of Raman spectroscopic measurements and DV-Xα molecular orbital calculations. The energy level structure of the non-spherically symmetric sp 3 structure of 20 carbon atoms shows values of energy gap corresponding to those obtained in the experiment. The results presented suggest that single impact of HCI on solid surfaces creates new nanostructure features, and HCI would be a good tool for collective material-modification-processing with nanoscale controllability.

From a developmental point of view, human testicular germ cell tumor (TGCT) can be traced back to the primordial germ cells in the embryo, which, upon transformation, become either seminoma or non-seminoma. Thus, TGCT provides a useful model system for the study of gene regulation involved in oncogenesis as well as development. In this study, we focused and analyzed the expression and epigenetic alteration of DNA-methyltransferase (DNMT) genes in TGCT tissues. The examined genes included DNMT1, DNMT3A and DNMT3B that function to maintain or generate a methylation status of genomic DNA. Using semi-quantitative reverse transcription-polymerase chain reaction, we found that the expression of DNMT3A, but not DNMT1 or DNMT3B, was up-regulated markedly in TGCT specimens compared to non-tumor testicular tissues. To explore mechanisms involved in the up-regulation of DNMT3A, we examined the methylation status of CpGs in the gene. The distal and proximal promoter regions of DNMT3A were non-methylated in both TGCT and non-tumor tissues. In contrast, non-tumor testicular tissues exhibited a mixture of methylated and non-methylated CpGs in intron 25 of DNMT3A, whereas most CpGs in intron 25 were demethylated in TGCT specimens. This difference in the degree of methylation was confirmed by Southern blot analysis, in which an EcoRI site in intron 25 could be digested only when the CpG was non-methylated. Thus, epigenetic alteration of intron 25 toward de-methylation is associated with increased expression of DNMT3A in TGCT. The intron 25 may represent a differentially-methylated region in DNMT3A that is modulated during development and/or tumorigenesis of germ cells.

The DV-X Molecular.- Orbital Calculation Method and Recent Development.- Algebraic Molecular Orbital Theory.- Analytical Expression of Molecular Integrals over Slater-Type Functions for Generating their Polynomial Expressions.- Atom-atom interaction potential from the Gaussian quadrature method and classical molecular dynamics.- Comparison of contributions to interatomic interactions between covalent and ionic bonds from total energy calculations.- Total energy calculation by DV-Xa method and its accuracy.- Comparative Study on Optical Properties of YPO4: Mn, Zr Phosphor by Experiment and Calculation.- Energy.- Expression of the Chemical Bond between Atoms in Hydrides and Oxides and Its.- Application to Materials Design.- Method for New Material Design in Dye-Sensitized Solar Cell.- Microscopic Approach to Water by Using the DV-X Method, and Some Innovative Applications.- Electronic structure and chemical bonding of Li1.1Nb0.9O2-y as a negative electrode material for lithium secondary batteries.- Chemical bonding, point defects and positron lifetimes in FeSi2 from first-principles calculations.- Structural Analysis of Al2TiO5 at Room Temperature and at 600 C by DV-X Approach (II).- Wavelength of Luminescence and Energy Level.- Structure of Binuclear Copper(I) Complex.

Slow Ar8+ impact with 400 eV of kinetic energy upon graphite followed by subsequent electron injection induced the transition from sp2 to sp3 hybridization, resulting in the formation of a non-conductive region at the metallic graphite surface. From the I–V characteristics measured by scanning tunneling spectroscopy, it was confirmed that the Ar8+ impact region showed an energy gap with ∼6 eV. The impact region was found to work as an electron emitter similar to the CVD-grown poly-crystalline diamond film after the further treatment in hydrogen ambient at 600 °C. It was confirmed from the Raman spectroscopic measurements that vacancies were introduced into the sp2 region by the slow Ar8+ impact, and also found that the most presumable sp3 cluster model which can explain experimental results had a defective and more planar structure from DV-Xa molecular orbital calculations.

Electron spin resonance (ESR) studies have been performed on newly synthesized AgII complexes of octaethylporphyrin (oep) cocrystallized with fullerenes (C60 and C70) using single crystals and polycrystals between 4 and 300 K. We have observed the fine structure in the ESR spectra of AgII(oep) C60; the fine structure is ascribed to the triplet spin states due to magnetic dipolar interactions between S = 1/2 spins of AgII ions in adjacent oep molecules. The analysis of the angular dependence of the g value and fine-structure splitting width for AgII(oep) C60 single crystals determines the angle between the Ag–Ag direction and the normal of the Ag–oep plane as 37°. The results of AgII(oep) C70 are similar to those of AgII(oep) C60. The spin susceptibility of all complexes almost obeys the Curie law, indicating the exchange interactions between the spins of Ag ions are negligible in the temperature region measured.

Seminoma constitutes one subtype of human testicular germ cell tumors and is uniformly composed of cells that are morphologically similar to the primordial germ cells and/or the cells in the carcinoma in situ. We performed a genome-wide exploration of the genes that are specifically up-regulated in seminoma by oligonucleotide-based microarray analysis. This revealed 106 genes that are significantly and consistently up-regulated in the seminomas compared to the adjacent normal tissues of the testes. The microarray data were validated by semi-quantitative RT-PCR analysis. Of the 106 genes, 42 mapped to a small number of specific chromosomal regions, namely, 1q21, 2p23, 6p21-22, 7p14-15, 12p11, 12p13, 12q13-14 and 22q12-13. This list of up-regulated genes may be useful in identifying the causative oncogene(s) and/or the origin of seminoma. Furthermore, immunohistochemical analysis revealed that the seminoma cells specifically expressed the six gene products that were selected randomly from the list. These proteins include CCND2 and DNMT3A and may be useful as molecular pathological markers of seminoma.

A substituted porphyrinatoplatinum(II), meso-tetrakis(4-t-butylphenyl)porphyrinatoplatinum(II), has been spectroscopically and structurally characterized. The 1H NMR signal from the β-protons of the pyrrole ring is observed as a singlet with a full-width at half maximum of 1.6 Hz, contrary to the reported quasi-triplet resonance attributable to the 1H–195Pt long-range coupling. The porphyrin nucleus is nearly planar in the solid state. All macrocycle atoms lie within approximately 0.06 A of the least squares mean plane with a pseudo-wave core conformation. The intramolecular Pt–N distances are 2.019(3) A.

The pressure effects on an S = 1 Haldane compound Ni(C 5 H 14 N 2 ) 2 N 3 (PF 6 ) (NDMAP) have been investigated through the magnetic susceptibility (χ) measurements using single crystalline sample...

An assembled compound (BEDT-TTF)2[Mn2Cl5(EtOH)] (1) consisting of two structural lattices of Mn(II)–Cl one-dimensional (1-D) chains and bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) stacking layers was synthesized by electrochemical crystallization. Compound 1 crystallized in triclinic space group P-1 (#2) with a=13.1628(5) A, b=20.3985(9) A, c=7.4966(3) A, α=98.3498(8)°, β=104.980(1)°, γ=74.602(2)°, V=1868.3(1) A3, and Z=2. The 1-D chains and the stacking layers are aligned along the c-axis of the unit cell. The 1-D chain is described as [Mn2Cl5(EtOH)]∞− in which two Mn(II) ions and four Cl− ions form a ladder-like chain with Kagome (cuboidal) sublattices, and the remaining Cl− ion and an ethanol molecule cap the edge-positioned Mn(II) ions of the chains. The BEDT-TTF molecules are packed between the Mn–Cl chains (ac-plane), the intermolecular S·S contacts of which are approximately found in the range 3.440(2)–3.599(2) A. The packing feature of BEDT-TTF molecules is very similar to that of (BEDT-TTF)2ClO4(TCE)0.5 (TCE=1,1,2-trichloroethane) (J. Am. Chem. Soc., 105, 297 (1983)). Regarding the electronic state of each BEDT-TTF molecule, Raman spectroscopic analysis and ESR study revealed the presence of half-valence BEDT-TTF molecules (charge delocalization) in 1. Magnetic measurements clearly demonstrated that the paramagnetic spins on the 1-D chain [Mn2Cl5(EtOH)]∞− arrange antiferromagnetically in the low-temperature region. Additionally, 1 exhibits metallic conductivity in the temperature range 2.0–300 K (σ=21 S cm−1 at 300 K and 1719 S cm−1 at 2.0 K), due to the contribution of the stacked BEDT-TTFs. Consequently, these peculiarities that correspond to antiferromagnetic/metallic conductivity demonstrate the “bi-functionality” of 1.

We report magnetic properties of CuSb 2− x Ta x O 6 with tri-rutile type structure. Solubility limit was determined to be x =1.0 by the solid-state reaction and X-ray diffraction measurements. The value of J , the magnetic interaction obtained by Bonner–Fisher fitting, was found to decrease gradually with Ta content x . The value of T N also decreases with x and seems to be zero at x =0.6. As a result of our structural analysis, this fact shows the crossover from one-dimensional to two-dimensional magnetic system with a local distortion caused by Ta substitution. Although the ground state of the compound with x >0.6 is not clear, it can be considered that the long-range antiferromagnetic order disappears and that the quantum critical regime such as a spin-singlet state is realized in this system.

ESR measurements have been made on a newly synthesized cocrystallite of C60 with the CoII complex of 5, 10, 15, 20-tetrakis[3, 5-(di-tert-butyl)-phenyl]porphyrin (tbp) single crystal to study the strong intermolecular interactions which are suggested by x-ray structural analyses. A single anisotropic ESR absorption line is observed at room temperature with the principal g-values g⊥ = 2.423 and g∥ = 2.005, which are typical values for the low-spin CoII ions (S = 1/2). The antiferromagnetic superexchange interaction between CoII ions via C60 is confirmed from the observation of the finite Weiss temperature, which is further supported by the absence of the hyperfine splitting due to 59Co (I = 7/2) nuclei. As the temperature is lowered, the g⊥-value decreases monotonically suggesting an increase of the crystal-field splitting energy. This result is consistent with the fact that the intermolecular distance between CoII and C60 becomes shorter as the temperature decreases. The peak-to-peak ESR linewidths ΔHpp along both principal axes increase with temperature due to the shorter spin-lattice relaxation time.

The ligand substitution reaction of Ru2(O2CCH3)4Cl with 2-amino-4,6-dimethylpyrimidine (Hadmpym) under gentle refluxing conditions in methanol led to the formation of a bridging-ligand mono-substituted compound, [Ru2(O2CCH3)3(admpym)(Cl)(MeOH)] (1). Compound 1 crystallized in monoclinic space group P21/n (no. 14) with a=8.3074(8) A, b=12.3722(8) A, c=18.913(1) A, β=95.559(3)°, V=1934.8(3) A3, and Z=4. Temperature dependence of the magnetic susceptibility of 1 revealed it to be in a spin ground state S=3/2 arising from the electronic configuration of σ2π4δ2(δ*π*)3. Compound 1 undergoes three metal-centered redox reactions in electrochemistry: E1/2 (ox)=+0.72 V (Ia/Ic

Six Mn(III) quadridentate Schiff base compounds with N,N′-(1,1,2,2-tetramethylethylene)bis(salicylideneiminato) dianion (saltmen2−) and N,N′-(1,1,2,2-tetramethylethylene)bis(naphthylideneiminato) dianion (naphtmen2−) have been prepared and structurally characterized: [Mn(saltmen)(H2O)]ClO4 (1), [Mn(naphtmen)(H2O)]ClO4 (2), [Mn(saltmen)(NCS)] (3), [Mn(naphtmen)(NCS)] (4), [Mn(saltmen)(Cl)] (5) and [Mn(naphtmen)(Cl)] (6). Among them, 1 and 2 form phenolate-bridged out-of-plane dimers with Mn–Ophenolate bond distances of 2.434(2) and 2.662(3) A, respectively. X-Ray diffraction analysis shows that compounds 3, 4 and 6 can also be considered as out-of-plane dimers in spite of long Mn–Ophenolate interacting distances (3.441(2) A for 3, 3.758(3) A for 4 and 3.505(5) A for 6). In contrast with the above compounds, 5 is a discrete Mn(III) mononuclear complex with a square-pyramidal geometry. In the dimer series (compounds 1–4 and 6), the out-of-plane intermolecular distance varies dramatically according to equatorial ligands, saltmen2− or naphtmen2−, and axial ligands, H2O, NCS− and Cl−. The relation between substitution of the ligands and structural parameters of the dimeric molecules are discussed. Magnetic susceptibility studies reveal interesting intra-dimer ferromagnetic interactions between Mn(III) ions. Our work reports on these new S = 4 building blocks that open new possibilities in the design of magnetic molecule-based materials.

The cocrystallites that contain C 60 , C 70 and endohedral metallofullerenes with metal complexes of macrocycles are reviewed. Metal complexes of porphyrin cocrystallites with fullerenes form solids with remarkably close contact between the curved π surface of a fullerene and the planar π surface of a porphyrin, without the need for matching convex with concave surfaces. The structures of metal octaethylporphyrins (oeps) in C 60 ·Pd(II)(oep)·1.5C 6 H 6 , C 60 ·Cu(II)(oep)·2C 6 H 6 , C 60 ·Ag(II)(oep)·2C 6 H 6 and C 60 ·2Ni(II)(oep)·2C 6 H 5 Cl reveal the remarkable anti -formed oep configurations, with the four ethyl groups of the metal oep portions lying on both the same and the opposite sides of the porphyrin plane toward the C 60 . On the other hand, syn -formed metal oeps are observed in the many cases of metal oep compounds, suggesting that there is a face-to-face interaction between two adjacent oep planes. A new cocrystallite which exhibits a strong intermolecular interaction between fullerene C 60 and the Co(tbp) is also reviewed, where tbp denotes a dianion of tetra(bis- tert -butylphenyl)porphyrin. The intermolecular interactions of the anti - and syn -formed metal oeps in the cocrystallites containing fullerenes are also described by DV-Xα molecular orbital calculation.