塚田 学

It is empirically known that titanium dioxide nanoparticles stabilize the contact and frictional charge of the host polymers to which they are added. However, the mechanism for the stabilization process has not yet been elucidated. In this study, polyester films doped with titanium dioxide nanoparticles of different crystalline forms were triboelectrically charged and the effect of humidity on their charging characteristics was subsequently investigated to elucidate the charge stabilization mechanism. Our first finding was that the rutile-, rutile–anatase mixed crystal (P25)-, and amorphous-dominant-type titanium dioxide nanoparticles reduced the sensitivity of the films to humidity (humidity dependence), while the anatase-type titanium dioxide enhanced the humidity dependence. This difference in action was explained by associating it with the different water adsorption forms on the major crystalline surface of each titanium dioxide type. The second finding was that doping with titanium dioxide nanoparticles, particularly rutile and P25 nanoparticles, reduced fluctuations in the amount of tribocharges of the polyester film. This crystalline-form-dependent difference in action was considered to be based on the depth of the electron traps involved in each titanium dioxide type. The above two findings have allowed us to propose the first mechanism of tribocharge stabilization by titanium dioxide.

The achievement of molecular orientation control by rubbing and pressing poly(3-alkylthiophene)s is a powerful technique to improve the performance of organic electronic devices. We report here that the rubbing and pressing of blackish-brown 3-methoxythiophene oligomer powders yield layer and tablet samples with gold tones, respectively. Specular reflectivity, colorimetric, and X-ray diffraction measurements reveal that this gold tone is caused by an increase in the ratio of edge-on lamellar crystallites to face-on ones, which is promoted by rubbing/pressing. In contrast to the 3-alkylthiophene polymer, which develops a dominant face-on lamellar structure, rubbing of the 3-methoxythiophene oligomer increases the relative amount of edge-on lamellar crystallites to face-on lamellar ones. Furthermore, gold tone development in the tablet samples is limited to the near-surface area, despite the fact that pressure is also applied to the tablet bulk. These specific chemical events are explained by considering the repulsive interactions between the 3-methoxythiophene backbone and the functional groups on the surface of the substrate employed during the rubbing/pressing processes. Despite the lower applied pressure, gold tone development by rubbing is accompanied by a higher reflective property than by pressing because of the formation of larger relative amounts and sizes of edge-on lamellar crystallites, which are responsible for the gold tone.

Solution-cast coating films of perchlorate-doped oligo(3-methoxythiophene) exhibited a gold-like luster similar to that of metallic gold despite the involvement of no metals. However, the development mechanism of the luster remains ambiguous. To understand the mechanism, we performed scanning electron microscopic analysis, variable-angle spectral reflectance measurements, and ellipsometry measurements on ClO4−-doped oligo(3-methoxythiophene) cast film with a gold-like luster. The results revealed that the lustrous color of the film was not induced by the submicron-sized regular structures (structural color), nor by the high-density free electrons (reflective response based on Drude model), but by the large optical constants (refractive index and extinction coefficient) of the film, as speculated previously.

<p>Ethylene-bridged polysilsesquioxane/hollow silica particle hybrid films were prepared by the sol–gel reaction. The hybrid film containing hollow silica particles exhibited good thermal insulation properties and thermal stability.</p>

The hybrid antifogging materials poly(3-aminopropyl)silsesquioxane (PAPS) and poly(3-(2-aminoethylaminopropyl)silsesquioxane) (PAEAPS) were prepared by sol-gel reactions that are autocatalyzed by the amine moieties of the monomers. PAPS and PAEAPS show good film-forming abilities, and the films obtained were found to be uniform and pinhole-free. X-ray diffraction analysis of PAPS and PAEAPS films indicated the formation of ladder-like structures. The PAPS and PAEAPS films exhibit high water uptakes of 34 and 42%, which are 1.2 and 1.5 times that of the typical antifogging polymer poly(vinyl alcohol) (PVA), respectively. Furthermore, the PAEAPS film exhibits a scratch resistance 4-6 times that of PVA, and a glass substrate bearing a PAEAPS film remained transparent after removal from a refrigerator. Thus, PAEAPS films exhibit high transparency under humidified conditions and show good antifogging ability.

Environmentally friendly methods for the synthesis of T8H were developed. A combination of triethoxysilane (TES), concentrated HCl aqueous solution, and FeCl3 produced T8H with almost the same yield as the previously known methods. We also found that HNO3 could be used instead of HCl, resulting in a similar yield. No toxic gases were generated during the reaction with HNO3. Additionally, the synthesis of T8H based on TES did not generate dangerous substances such as hydrogen chloride and methanol, unlike when trichlorosilane or trimethoxysilane are used. Therefore, our new method for the synthesis of T8H is considered to be safer, although the yield is the same as the conventional methods.

<p>Modeling and prediction of molecular weight by MBR.</p>

<p>The benzenedithiolate-bridged MoFe complexes were synthesized and the oxidation states of the metal centers elucidated.</p>

Near-infrared (NIR)-shielding films based on polysiloxane or polysilsesquioxanes and poly(3,4-ethylenedioxythiophene)-poly(4-styrene sulfonate) (PEDOT-PSS) were synthesized via a sol-gel reaction. Phase-separated mixtures of tetraethyl orthosilicate (TEOS) or methyltriethoxysilane (MTES) with an aqueous dispersion of PEDOT-PSS formed deep-blue homogeneously dispersed sols after stirring. Thin films were prepared by depositing the resulting homogeneously dispersed sols on a glass substrate by spin coating and heating. PEDOT-PSS/TEOS films maintained uniform flat surfaces after 10 coatings. MTES-based films exhibited mottled patterns with nonuniform surfaces. The 10-layer TEOS-based film has high NIR-shielding properties with moderately visible transmittance. NIR absorption by the PEDOT-PSS/TEOS hybrid suppresses air temperature elevation. The five-layer TEOS-based film showed similar NIR-shielding ability and slightly lower visible light transmittance compared with tin-doped indium oxide glass. The 10-layer TEOS-based film exhibited a 15.6% lower temperature rise than the uncoated glass substrate. Specifically, this is an environmentally friendly NIR-shielding material. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 48367.

© 2020, Springer Science+Business Media, LLC, part of Springer Nature. Abstract: The facile preparation of bulk porous silica and a desulfurization ability of this silica-supported ZnO as application are reported. Bulk porous silica was prepared by the sol–gel method using tetraethoxysilane (TEOS) and surfactant as a template. The swollen gel was filled in a plastic vial followed by curing for 1 day. Bulk porous silica was prepared by the calcination of the cured gel. The bulk porous silica was characterized by nitrogen adsorption–desorption measurements and transmission electron microscopy (TEM). The bulk porous silica has micropore and mesopore: the micropore distribution was calculated to be 1.7 nm by the MP method and the mesopore-size distribution was calculated as 6.3 nm by the Barrett–Joyner–Halenda method. The volume of micropore was larger than that of mesopore; hence, bulk porous silica would be formed as a pillared-clay-like structure. Bulk porous silica-supported ZnO was prepared by the impregnation of ZnCl2 followed by calcination in air. The content of ZnO in bulk porous silica (1.9, 15.3, 33.8, and 46.2 wt%) was determined by inductively coupled plasma atomic emission spectrometry, and the ZnO content was depended on the concentration of ZnCl2 aqueous solution. Characterization was achieved by nitrogen adsorption–desorption measurements and TEM. The specific surface area decreased with increasing concentration of ZnO because ZnO deposited onto wall within pores. The sulfurization capacity of the bulk porous silica-supported ZnO was evaluated, and the sulfurization capacity per gram of the bulk porous silica-supported 46.2 wt% ZnO showed 12.56 mg/g. [Figure not available: see fulltext.].

<p>著者らはこれまで，過塩素酸イオンがドープされた3-メトキシチオフェン重合体の塗布膜が，金色調光沢を示すことを示してきた．本研究では，過塩素酸イオンの代わりにテトラフルオロホウ酸イオンをドーパントに用いたところ，膜の色および光学物性が異なる結果が得られた．具体的には，ドーパントが過塩素酸イオンの場合は，膜が黄色みの強い金色調光沢色を示すのに対して，テトラフルオロホウ酸イオンの場合は，緑色みの反射が加わることで，より白色に近い金色調光沢色となった．また後者の膜の正反射率は，過塩素酸イオンドープ膜に比べて増加した．それぞれの重合体の分子量およびドープ率に大きな差は見られなかった．一方，各膜のX線回折測定の結果から，テトラフルオロホウ酸イオンの場合には，金色調光沢発現の要因の一つであるedge-onラメラ構造の割合が高いことが判明した．これらのことから，色調の違いおよび正反射率の増加が生じたのは，テトラフルオロホウ酸イオンの存在により膜中のedge-onラメラ結晶の存在割合が増加したためであることが示唆された．</p>

© 2019 Elsevier Ltd Two compounds, 6-(1-azaazulen-2-yl)ethynylazulene (8) and 6-(2-azulenyl)ethynylazulene (10), were synthesized using the Sonogashira-Hagihara cross-coupling reaction followed by decarboxylation with concentrated phosphoric acid. Compounds 8 and 10 were characterized by 1H and 13C nuclear magnetic resonance (NMR) spectroscopy, mass spectrometry, ultraviolet–visible (UV–Vis) spectroscopy, cyclic voltammetry, and density functional theory (DFT) calculations. Based on the results, both compounds were confirmed to have π-conjugation throughout their molecular structures. The acidic responsivity of compounds 8 and 10 was evaluated using UV–Vis and 1H NMR spectroscopy. Compound 8 was found to be highly sensitive to trifluoroacetic acid, with its 1-azaazulenyl moiety acting as a base. Compound 10 generated azulenium cations when mixed with excess amounts of trifluoroacetic acid.

Titanium phosphonate clusters were synthesized by the reactions of titanium tetraisopropoxide (Ti(OiPr)4) with arylphosphonic acids (ArPO3H2, Ar = Ph, 1-Nap, 4-MeOPh, 4-FPh, 4-ClPh, 4-BrPh, and 4-BrBn) and H2O in tetrahydrofuran (THF) at room temperature. [Ti4(μ3-O)(OiPr)5(μ-OiPr)3(O3PAr)3]·solv (Ar = Ph (1), 1-Nap (2), 4-MeOPh (3), 4-FPh (4), 4-ClPh (5) solv = thf for 1 and 2 or 2-propanol for 3–5) were isolated as new Ti4P3-type clusters, while Ti7(μ3-O)2(OiPr)6(μ-OiPr)6(O3PBnBr)6 (6) was isolated as a Ti7P6-type cluster. A co-crystal of Ti4P3- (7a) and Ti7P6-type (7b) clusters were obtained when 4-BrPhPO3H2 was used, and [Ti(OiPr)(acac)(O3PPh)]4 (8), a new cage cluster, was obtained when Ti(acac)2(OiPr)2 (Hacac = acetylacetone) was reacted with PhPO3H2.

Syntheses of two homonuclear hydride complexes, viz. hydride-bridged ruthenium dinuclear complex [Ru(η6-C6Me6)(S2C6H4)RuClH(PPh3)2] (3) and dihydride ruthenium dinuclear complex [Ru(η6-C6Me6)(S2C6H4) RuH2(PPh3)2] (4), have been described. Complex 4 was obtained as a mixture of cis- and trans-dihydride isomers in a 10:1 M ratio, as indicated by the proton ratio in 1H NMR spectra. The dinuclear complex 4 reacted with carbon monoxide for 30 min and 1 day under similar conditions to produce dicarbonyl complex [Ru(η6-C6Me6)(S2C6H4)Ru(CO)2(PPh3)] (5), and tetracarbonyl complex [Ru2(CO)4(PPh3)2(S2C6H4)] (6), respectively. On the other hand, treatment of 4 with carbon dioxide under ambient conditions was found to produce formic acid.

To develop advanced materials using metal complexes, it is better to prepare metal complexes contained in composite or hybrid films. To achieve this purpose, we synthesized ruthenium complexes with dihalogen-substituted benzendithiolate ligands, [(?6-C6Me6)Ru(S2C6H2X2)] (X = F, 3,6-Cl, Br, 4,5-Cl), 1b–1e. We also investigated preparation of 1c or 1e containing polysiloxane composite films and their reactivity to CO gas. All ruthenium complexes 1b–1e reacted with CO gas, and carbonyl ligand adducts 2b–2e were generated. Ruthenium complexes 1b–1e show two strong absorption peaks around 550 and 420 nm. After exposure to CO gas, these absorption peaks were immediately decreased without a peak shift. A similar trend was observed in 1c or 1e containing polysiloxane composite films. These results indicate that 1c and 1e were easily converted into 2c and 2e, both in the solution and the polysiloxane film during CO gas exposure.

Organic-inorganic hybrids containing [Ti-4(mu(3)-O)(OiPr)(5)(mu-OiPr)(3)(O3PPh)(3)] center dot thf as element-blocks were prepared by hybridization with poly(dimethylsiloxane), poly(methylsilsesquioxane), poly(ethoxysilsesquioxane), poly(methyl methacrylate), poly(vinyl alcohol), poly(4-vinylphenol), poly(styrene-co-allyl alcohol) or poly(bisphenol A-co-epichlorohydrin). The concentration of the titanium cluster was increased to 40 wt% to form crack-free films with high transparency. The temperature at which 10 wt% weight loss occurred increased with the concentration of the titanium cluster because an alcohol exchange reaction was expected between the titanium cluster and polymers. The mechanical strengths and strains of poly(dimethylsiloxane) hybrids were very low. The tensile strengths and elongations of poly(methyl methacrylate) hybrids increased with the increase in the titanium cluster concentration. The tensile strengths and elongations of poly(vinyl alcohol) hybrids were highest when the titanium cluster concentration was 10 wt%.

A series of 2-arylamino-l-azaazulenes were synthesized by the Buchwald-Hartwig cross coupling reaction. The resulting compounds were characterized by H-1 NMR, C-13 NMR, HRMS analyses, and elemental analysis. X-Ray crystallographic analysis revealed that 2-(1-naphthylamino)-1-azaazuleneexists in dimeric form with two intermolecular N-H center dot center dot center dot N hydrogen bonds in its crystal structure.

Octakistetramethylammonium octasilsesquioxane (Q(8)(TMA)) was synthesized from water glass (No. 3) by neutralization, extraction with tetrahydrofuran, and condensation reaction using tetramethylammonium hydroxide. Octakisdimethylsilyl octasilsesquioxane (Q(8)(DMS)) was synthesized by the reaction of Q(8)(TMA) with chloro(dimethyl) silane. An all-siloxane- type cage-containing polymer was synthesized by the reaction of Q(8)(DMS) with water by using diethylhydroxylamine as a catalyst. The reaction of Q(8)(DMS) with diphenylsilanediol was carried out to provide oligomers. This reaction was carried out by the addition of Q(8)(DMS) twice to isolate a cage-containing polymer with a weight-average molecular weight of 18,000.

Four hexacoordinated molybdenum complexes, [Mo(S2C6H4)(CO)2(PMenPh3-n)(2)] (n = 0 (1), 1 (2), 2 (3), 3 (4)), were synthesized via the one-pot reaction of [Mo(eta(3)-C3H5)(Br)(CH3CN)(2)(CO)(2)], 1,2-H(2)bdt (bdt = benzenedithiolate), and phosphines. The structure of all complexes was successfully characterized by single crystal X-ray diffraction. For the stabilization these complexes, the bdt ligand and the axial phosphine ligands are not located on the ideal vertexes of octahedron in order to reduce the destabilizing overlapping of molecular orbitals. Therefore, six-coordinated complexes generally adopt an octahedral geometry, the complexes 1-4 showed structures intermediate between a distorted octahedron and a regular trigonal prism, i.e. configurations far from the ideal octahedral geometry. All complexes underwent a two-step 2e(-) reduction reaction, with the reduction potential of the Mo center shifting towards negative values moving from compound 1 to compound 4. (C) 2016 Elsevier Ltd. All rights reserved.

A series of 3,6- and 4,5-dihalogen-substituted 1,2-benzenedithiol (H(2)bdt) ligands, (3,6-(X21-4,5-X22)-1,2-H(2)bdt) (X-2 = H, X-1 = F (1a), Cl (1b), Br (1c); = H, X-2 = CI (4)), and their cobalt complexes, [Cp*Co(3,6--X-2(1)-4,5-X-2(2)-1,2-bdt)] (X-2 = H, X-1 = F 2a), Cl (2b), Br (2c); X-1= H, X-2 = Cl (5)), were synthesized by a modified selective thiolation reaction. The 1,2-diphenyl-substituted cobaltadithiolene complex (2d) was also synthesized. The molecular structures of all cobaltadithiolene complexes were determined by single crystal X-ray diffraction analysis. Compounds 2a, 5 and 12 showed unique packing structures with intermolecular interactions that confirmed them as the first examples of half-sandwich-type metalladithiolene complexes with a Cp* ligand. The effects of the benzene substituent type and position on the metalladithiolene ring were investigated using UV-vis spectroscopy measurements and cyclic voltammetry. The results inditate that substitution of halogen atoms at the 3 and 6 position of the benzene ring had a larger effect on the dithiolene ring than substitution at the 4 and 5 positions. (C) 2016 Elsevier Ltd. All rights reserved.

A liquid scintillator containing a zirconium β-keto ester complex has been developed for the Zirconium COmplex in liquid Scintillator (ZICOS) experiment which is new project of neutrinoless double beta decay search. We are aiming to develop a detector which has a good energy resolution (3.5% at 3.35 MeV), a large light yield (60% that of BC505) and a low background rate (0.1 counts/tonne・year) with several hundred kg of 96Zr isotope, so we have investigated the zirconium β-keto ester complexes such as tetrakis (isopropyl acetoacetato) zirconium and tetrakis (ethyl acetoacetato) zirconium, which have high solubility (over 30 wt.%)in anisole. We measured the performance of liquid scintillator containing these zirconium β-keto ester complexes, and obtained 48.7+-7.1% of the light yield of BC505 and the energy resolution of 4.1+-0.6% at 3.35 MeV assuming 40% photo coverage of the photomultiplier in the detector. This results reached our initial goal, so we estimated that ZICOS experiment should be sensitive to <mV> < 0.2 - 0.3 eV assuming gA = 1.25, gPP = 1.11 and QRPA model, if a radius of the balloon is 1.5 m and the balloon is filled with a liquidscintillator containing 10 wt.% concentration of a zirconium β-keto ester complex with an enriched 96Zr.

The first dianionic compound bearing a bond between two pentacoordinated tin atoms, a distannate, was synthesized in a stable form by using two sets of an electron-withdrawing C,O-bidentate ligand on each tin atom. The structure of the distannate was determined by NMR spectroscopy and X-ray crystallographic analysis. The Sn-Sn bond of the distannate was shown to be a single bond featuring high s-character. The (1)J(Sn-Sn) coupling constant was larger than that of Sn(sp(3))-Sn(sp(3)) bonds found in most hexaorganodistannanes. This bond feature was also supported by computational studies. The Sn-Sn bond was cleaved by treatment with hydrochloric acid, which shows a different reactivity to the homonuclear bonds of pentacoordinated disilicates and digermanates.

POSS derivatives were synthesized by the dehydrogenative reaction of octahydrosilsesquioxane with alcohols. The reaction with 2-methacryloyloxyethanol, 1-methacryloyloxy-2-propanol, and diphenyl methanol provided corresponding octaalkoxylated POSS derivatives. The reaction with ethylene glycol provided silica gel, while the reaction with 2,3-butanediol or pinacol provided polymers and oligomers, respectively. The product by the reaction of POSS with 2,2-butanediol was spin-coated on a silicon wafer and heated to provide a silica coating film with a pencil-hardness of 2H. (C) 2015 The Ceramic Society of Japan. All rights reserved.

The addition of carbon monoxide to the ruthenium center of [((6)-C6Me6)Ru(S2C6H4)] (1) has been investigated. [((6)-C6Me6)Ru(CO)(S2C6H4)] (2) was obtained by the addition of CO gas to the ruthenium center of 1 in both solution and solid states. 1 was reproduced by treating 2 with an oxidant. A 1/polysiloxane self-standing hybrid film was also prepared and showed a dramatic color change upon transformation of 1 to 2 in polysiloxane hybrid film.

Polysiloxanes were prepared by acid-catalyzed controlled hydrolytic co-polycondensation of polymethyl (methoxy) siloxanes (PMS) and polymethoxysiloxanes (PMOS) obtained as macromonomers by acid-catalyzed controlled hydrolytic polycondensation of methyl(trimethoxy) silane and tetramethoxysilane, respectively. Co-polycondensation of the macromonomers with molecular weights M-w 2000 (PMS) and 400 (PMOS) provided polymethylsiloxane copolymers with molecular weights M-w 6500-15,000. The structure was confirmed to consist of block copolymers poly(PMS-block-PMOS) based on the results of gel permeation chromatography, isolation by fractional precipitation with THF and hexane, and H-1 and Si-29 NMR spectral analyses. The copolymers were soluble in organic solvents, except for hexane, and were fairly stable to self-condensation even without an end block. Transparent and flexible free-standing films were obtained from a 20 wt% THF solution of polymers. The surface morphology of films by FE-SEM and IR microscopic spectral analyses revealed cross-shaped crystalline materials on the film surface of poly (PMS-block-PMOS); these materials consisted of silsesquioxane unit structures depending on the compositions of PMS and PMOS. Graphical Abstract Polysiloxanes were prepared by acid-catalyzed controlled hydrolytic co-polycondensation of polymethyl( methoxy) siloxanes (PMS) and polymethoxysiloxanes (PMOS). The structure was confirmed to consist of block copolymers poly(PMS-block-PMOS). The surface morphology of transparent and flexible free-standing films revealed cross-shaped crystalline materials on the film surface of poly(PMS-block-PMOS); these materials consisted of silsesquioxane unit structures depending on the compositions of PMS and PMOS. [GRAPHICS]

polysilsesquioxane-based organic-inorganic hybrid membrane was prepared and applied as a proton-conducting membrane for fuel cells. poly(STES-ran-MTES), a random copolymer of ethyl 4-(2-methyl-3-triethoxysilylpropoxy) benzenesulfonate (STES) and triethoxy(methyl) silane (MTES) was synthesized by hydrolysis and condensation in the presence of hydrochloric acid under a nitrogen stream. The molecular weight was 7500-7600 g mol(-1), and the percentage of hydrolyzed ethoxysulfonyl group was 32-50%. A poly(STES-ran-MTES) membrane was prepared by heating for several days, which showed thermal resistivity up to 200 degrees C and proton conductivity of 2.0 x 10(-5) to 1.1 x 10(-3) S cm(-1) at room temperature. By contrast, a membrane of a block copolymer, poly(SPES-block-PMS), showed proton conductivity of 2.5 x 10(-3) S cm(-1). The proton conductivity of the poly(3-(4-ethoxysulfonylphenoxy)-2-methylpropyl) silsesquioxane (SPES) membrane increased from 2.7 x 10(-3) S cm(-1) at 25 degrees C to 1.0x10(-2) S cm(-1) at 110 degrees C. The proton conductivity of the SPES membrane increased from 2.7 x 10-3 S cm(-1) at relative humidity (RH)=25-30% to 2.0 x 10(-3) S cm(-1) at RH=60% and 1.4 x 10(-1) S cm(-1) at RH=90%. The mixture of SPES and poly(vinyl alcohol), poly(ethylene oxide) or polyoctahedralpolysilsesquioxane showed proton conductivities of 2.7 x 10(-3), 1.5 x 10(-3) and 2.5 x 10(-3) S cm(-1), respectively, at 25 degrees C and RH=25-30%. The open-circuit voltage of the SPES membrane was 0.92 V.

A liquid scintillator containing a zirconium β-keto ester complex has been developed for the ZIrconium Complex in Organic Scintillator (ZICOS) neutrinoless double beta decay experiment. We are aiming to develop a detector which has a good energy resolution (4% at 2.5 MeV), a large light yield (60% that of BC505) and a low background rate (0.1 counts/tonne・year) with several tonnes of 96Zr isotope, so we have investigated the zirconium β-keto ester complexes tetrakis (isopropyl acetoacetato) zirconium and tetrakis (ethyl acetoacetato) zirconium, which have high solubility (over 10 wt.%) in anisole. We measured the performance of liquid scintillators containing these zirconium β-keto ester complexes and obtained 40% of the light yield of BC505 and energy resolution of 4.1% at 2.5 MeV assuming 40% photo coverage of the photomultiplier in the ZICOS detector. Thus we almost achieved our initial goal. Preliminary investigations indicate that tetrakis (diethyl malonato) zirconium will give us no quenching of the light yield and an energy resolution of 2.9% at 2.5 MeV. This will be a suitable complex for the ZICOS experiment, if it has a large solubility.

The first dianionic compounds bearing a bond between two pentacoordinated germanium atoms have been synthesized in a stable form as candidates for a core unit to construct unprecedented structures in group 14 element chemistry. X-ray crystallographic analysis and computational study indicated the single-bond character of the GeGe bond. They were reversibly converted to the anionic and neutral GeGe-bonded compounds while maintaining the coordination number of the germanium atoms. The interconversion features changes in structures around the germanium atoms, including changes from a staggered conformation of the GeO bonds to a parallel conformation.

2-Amino-(1-(2-nitrophenylsulfinyl)azulene derivatives were synthesized by the reaction of 2-aminoazulene with 2-nitrobenzenesulfonyl chloride. Crystal structures of these compounds were determined by X-ray diffraction analysis. The sulfur atom derived nosyl group shows unique geometry. Furthermore, a reaction using 4-nitrobenzenesulfonyl chloride is also demonstrated.

An organic-inorganic hybrid was prepared by simply mixing a fullerene derivative with polymethoxysiloxane. First, C-60 was subjected to a radical addition reaction with 4,4'-azobis(4-cyanovaleric acid) to provide a C-60 derivative. Polymethoxysiloxane was prepared by a controlled hydrolytic condensation of tetramethoxysilane. These two compounds were mixed and heated to provide hybrid bulk body. The hybrid bulk body showed high mechanical strength and elastic modulus compared with polymethoxysiloxane or the C-60/polymethoxysiloxane hybrid. The formation of a dense siloxane network was established by a homogeneous mixing of the C-60 derivative with polymethoxysiloxane.