bluuebunny/crossref_metadata_2025 huggingface dataset:
Demetalation of (5,10,15,20-Tetraphenylporphyrinato)iron Complexes: Effect of Substituents at the o-Positions of Phenyl Groups
Authors: Hasegawa Etsuo , Matsubuchi Eriko , Tsuchida Eishun
Published: July 2006

The demetalation of a series of (5,10,15,20-tetrahenylporphyrinato)iron(III) complexes having bulky substituents at the o-positions of phenyl rings was studied in acetic acid in the presence of iron(II) chloride and HCl. The reaction occurred simultaneously with the reduction of Fe(III) porphyrin to Fe(II) porphyrin, since no demetalation was observed without iron(II) chloride. The pseudo-first-order rate constants, which were determined spectrophotometrically, decreased with an increase in the bulkiness of the o-substituents on the phenyl rings. The atropisomeric structures of the products were determined by high-resolution NMR measurements.
Synthesis of Pyrazole Nucleosides Using Acylketene Dithioacetal Derivatives
Authors: Yokoyama Masataka , Ikuma Toshihiro , Sugasawa Sadataka , Togo Hideo
Published: July 2006

Several nucleosides bearing pyazole ring as the base moiety were synthesized by the reaction of d-ribofuranosylhydrazine or 2-deoxy-d-ribosuranosylhydrazine with easily available acylketene ditioacetal derivatives.
X-Ray Crystal Structures of Octahedral Diaquabis(N,N-dialkyl-ethylenediamine)nickel(II) Complexes Possessing Elongated Nickel(II)–Nitrogen Bonds along Axial Direction
Authors: Ihara Yoshinori , Satake Yasuhiro , Fujimoto Yumi , Senda Hitoshi , Suzuki Masatatsu , Uehara Akira
Published: July 2006

The structures of two diaquabis(N,N-dialkylethylenediamine)nickel(II) chlorides ([Ni(H2O)2(diamine)2]Cl2·nH2O) were determined by X-ray crystallographic studies, where diamine is N,N-dimethylethylenediamine(NN-dmen) or N,N-diethylethylenediamine (NN-deen). Both complexes are trans and crystallize in the monoclinic space group P21⁄n. The unit cell parameters of the NN-dmen complex, NiCl2C8N4O2H32, are a=7.531(1), b=13.092(1), c=9.591 Å, β=107.76(1)°, and Z=2, and those of the NN-deen complex, NiCl2C12N4O2H36, are a=9.154(1), b=8.692(1), c=12.395(2) Å, β=104.46(1)°, and Z=2. In trans-[Ni(H2O)2(NN-dmen)2]Cl2·2H2O and trans-[Ni(H2O)2(NN-deen)2]Cl2, the Ni–NMe2 and Ni–NEt2 bond distances (2.183 and 2.271 Å) are much longer than the Ni–NH2 distances (2.078 and 2.064 Å), forming tetragonally distorted octahedrons with four close in-plane neighbors(N2O2) and two remote axial ones(N2). It is apparent that this distortion originates from the steric requirement of N-substituted groups. Such a distortion significantly affects the electronic spectra of these complexes.
Chromatographic Optical Resolution Based on the Chiral Discrimination between Ions of the Same Sign, Anionic Cobalt(III) Complex Racemates and Anionic Selector [Sb2(d-tart)2]2−
Authors: Koine Norio
Published: July 2006

Column chromatographic optical resolutions of twenty-six typical univalent anionic cobalt(III) complexes, e.g., [Co(edta)]− and fac-[Co(NO2)3(edma)]−, were carried out, using as a chiral eluent an aqueous solution of [Sb2(d-tart)2]2− on a strongly basic anion exchanger, where edta=ethylenediamine-N,N,N′,N′-tetraacetate(4-), edma=ethylenediamine-N-acetate(1-), and d-tart=d-tartrate(4-). The racemates were resolved with separation factors comparable to those obtained in conventional resolutions by use of cationic selectors. From a comparison of elution orders of enantiomers and separation factors obtained for the racemates, a chiral discrimination mechanism without direct contact between the racemate and selector was proposed.
Reactions of 2-Aminoazulenes with Electron-Deficient Acetylenes
Authors: Abe Noritaka
Published: July 2006

2-Aminoazulene (1a) reacted with dimethyl acetylenedicarboxylate (DMAD) to give dimethyl 1,2-azulenedicarboxylate, tetramethyl 2,2′-(2-amino-1,3-azulenediyl)bis[fumarate], and dimethyl 2-(4-methoxycarbonyl-2-oxo-l,2-dihydroazuleno[2,1-b]pyridin-10-yl)fumarate. The reaction of ethyl 2-amino-1-azulenecarboxylate (1b) with DMAD gave dimethyl 2-(2-amino-3-ethoxycarbonyl-1-azulenyl)fumarate and 10-ethyl 4-methyl 2-oxo-1,2-dihydroazuleno[2,1-b]pyridine-4,10-dicarboxylate (8a). The treatment of 8a with phosphoryl chloride gave the 2-chloroazuleno[2,1-b]pyridine derivative. Reactions of 1a and 1b with methyl propiolate gave corresponding Michael adducts and the azuleno[2,1-b]pyridin-3(4H)-one derivatives. Reactions of 1a and 1b with dibenzoylacetylene gave 4-benzoyl-2-phenylazuleno[2,1-b]pyridine derivatives.
Strong Acid Sites Created on Small–Sized Anatase
Authors: Nakabayashi Hirotoshi , Kakuta Noriyoshi , Ueno Akifumi
Published: July 2006

The acid properties of anatase having different crystalline sizes were estimated by measuring the temperature-programmed desorption (TPD) of ammonia as well as the infrared spectrum of adsorbed pyridine at elevated temperature. The size-controlled anatase was prepared by hydrolysis of the titanium tetraisopropoxide dissolved in propyl alcohol using various amounts of distilled water. The acid properties of the anatase were confirmed to be strongly affected by the crystalline size. Especially, the strength of acid sites was found to remarkably increase with a decrease in the crystalline size. The specific activity and the activation energy for 1-butene isomerization on the anatase also depended on the crystalline size. The generation of strong acid sites on the surface is discussed in terms of the crystalline size.
Intramolecular Electron Transfer and SN2 Reactions in the Radical Anions of 1-Benzoyl-ω-haloalkane Studied by Pulse Radiolysis
Authors: Kimura Norio , Takamuku Setsuo
Published: July 2006

A one-electron reduction of 1-benzoyl-ω-haloalkane (Cl, Br, I) by solvated electrons and a subsequent intramolecular reaction of the radical anions, thus formed, have been investigated by using a pulse radiolysis technique. The reaction mechanism, electron transfer (ET) or SN2, and the rate constants were found to change as a function of the nature of the halide and the methylene chain length of the substrate. Although the order of reactivity based on leaving halogen atoms was I, Br, and Cl, the ease of the SN2 reaction was found to be in the order Cl>Br>I. In addition, the reaction rates were also affected by the polarity of the solvent used. On the basis of these results, it is discussed how the ET–SN2 dichotomy takes place.
Effects of Temperature and Pressure on the Charge-Transfer Complex Formation through Hydrogen Bonding and Ionization Reactions between 2,6-Dibromo-4-[(3,5-dibromo-4-hydroxyphenyl)(2-ethoxycarbonylphenyl)methylene]-2,5-cyclohexadien-1-one and Amines
Authors: Nishimura Norio , Osawa Yoshihiro , Kuramoto Kohji , Sukemichi Kazuo
Published: July 2006

The effects of temperature and pressure on the formation of charge-transfer (CT) complexes between 2,6-dibromo-4-[(3,5-dibromo-4-hydroxyphenyl)(2-ethoxycarbonylphenyl)methylene]2,5-cyclohexadien-1-one (TBPE) and amines in nonpolar solvents have been studied, and the thermodynamic parameters estimated. It was found that the heat of formation (ΔH°) as well as the reaction volume (ΔV°) are largely negative, compared with those for ordinary CT complex formation. The electronic spectra in the visible region due to the outer CT complexes are well-characterized for primary and secondary amines in nonpolar solvents that have no proton-donating/-accepting nature. In other cases, the CT spectra are broad. Ionization of TBPE in polar solvents takes place as evidenced by the electronic spectrum of TBPE anion. However, ΔH° as well as ΔV° are unusually small. When Proton Sponge is used in nonpolar solvents, ion pairs are formed. In this case, ΔH° and ΔV° are largely negative as expected.
The Pitzer Formalism vis-à-vis the Mixture Rule for the Estimation of Apparent Molal Volumes of Aqueous NaCl–KCl, NaCl–KBr, and NaCl–K2SO4 Mixtures at 298.15 K
Authors: Mahapatra Prafulla , Bhattacharyya Moni Mohan , Sengupta Mihir
Published: July 2006

The density data reported by Wirth for aqueous solutions of KCl, KBr, and K2SO4 in NaCl solutions of five different fixed concentrations at 298.15 K have been used to calculate the apparent molal volumes of the mixtures; the results have been compared with those calculated by the Pitzer formalism as also the Young and Smith’s mixture rule.
Synthesis, Crystal Structure, and Property of Novel Tetranuclear Nickel(II) Complex with Multidentate Ligand 7-[(3,5-Dichloro-2-pyridyl)azo]-8-hydroxyquinoline-5-sulfonic Acid
Authors: Huang Hu , Kai Fumiaki , Asai Yoshifumi , Hirohata Masaaki , Nakamura Masaaki
Published: July 2006

Reaction of nickel(II) perchlorate with the title ligand (Hpahqs) in aqueous solution followed by standing for about six months produces a complex having the formulation [Ni4(pahqs)4(H2O)4]·20H2O. A single crystal X-ray analysis revealed that the complex contained the four nickel(II) and four ligand molecules and showed a novel structure of oxygen bridged tetranuclear nickel(II) complex. Crystal data: triclinic, space group P\bar1, a=17.884(7), b=22.071(8), c=12.819(8) Å, α=100.77(4)°, β=92.55(4)°, γ=71.46(4)°, Z=2. Except one N atom in each azo-group, all the other donor atoms in the ligand were fully used in coordination to nickel(II), forming either N,N,O- or N,O-chelate rings, simultaneously. The geometry around each of the four nickel(II) was distorted octahedron. The bond lengths of N1–N(N atoms in N,N,O-terdentate moieties) were elongated compared with those of the corresponding complex, and the lengths of N1–N(N atoms in quinoline rings) were kept almost similar values to those of the Ni(II)-8-hydroxyquinoline complex. The bond lengths of Ni–O were elongated compared with those of the nickel(II) complexes with either N,N,O- or N,O-chelate rings, resulting in the contraction of the angles of N–Ni–N or N–Ni–O. The angles of Ni–O–Ni around four nickel(II) sites were ca. 140°. The antiferromagnetic exchange interaction was operating between the four nickel(II) via bridging oxygen atoms.
Reversed Phase Extraction Chromatographic Separation of Germanium with Aliquat 336S from Citric Acid
Authors: Sahoo Sarat Kumar
Published: July 2006

Germanium was extracted from 0.005 mol dm−3 citric acid at a pH between 2.5 and 6.5 on a column of silica gel coated with Aliquat 336S as the stationary phase. Germanium was then stripped with 0.5 mol dm−3 hydrochloric acid and determined spectrophotometrically as its complex with phenylfluorone. Germanium was separated from alkali and alkaline earths, manganese, iron, cobalt, nickel, copper, and zinc in binary mixtures by the exploitation of difference in pH for formation of citrato complexes. It was separated from antimony, bismuth, tin, gallium, indium, and thallium by taking advantage of stability of chloro and sulfato complexes. This method was applied to the determination of germanium in coal fly ash.
Synthesis of Urushiols with Pentadecatrienyl Side Chain, Two Constituents of the Sap of a Lac Tree, Rhus Vernicifera
Authors: Miyakoshi Tetsuo , Kobuchi Hidenori , Niimura Noriyasu , Yoshihiro Yoshiro
Published: July 2006

Two phenolic lipids, 3-[(8Z,11Z)-8,11,14- and 3-[(8Z,11E,13E)-8,11,13-pentadecatrienyl]catechol, which are the major constituents of the sap from a Japanese or Chinese lac tree, Rhus vernicifera, have been synthesized via the Wittig reaction of ylides derived from 3,6- and 3,5-heptadienylphosphonium salts with 3-(8-oxooctyl)catechol diacetate.
Stepwise Reduction of Acetals to the Corresponding Hydrocarbons. A Mild and Effective Transformation via Carbinyl Bromides
Authors: Oriyama Takeshi , Ichimura Yuichi , Koga Gen
Published: July 2006

Stepwise reduction of two alkoxyl groups in acetal was effected by the action of triethylsilane along with acetyl bromide and SnBr2 and then of tributyltin hydride (or lithium aluminium hydride) providing methyl or methylene compounds in good yields under very mild conditions.
Triethylborane Induced Selective 1,4-Reduction of α,β-Unsaturated Carbonyl Compounds with Triphenyltin Hydride or Tributyltin Hydride
Authors: Nozaki Kyoko , Oshima Koichiro , Utimoto Kiitiro
Published: July 2006

Reduction of α,β-unsaturated ketones and esters with triphenyltin hydride or tributyltin hydride in the presence of triethylborane has been studied. Whereas the reaction of α,β-unsaturated ketones (R1CH=CHCOR2) with triphenyltin hydride provided the corresponding saturated ketones (R1CH2CH2COR2), treatment of α,β-unsaturated ester (PhCH=CHCOOMe or CH3CH=CHCOO–n-C6H13) afforded an adduct (PhCH2CH(SnPh3)COOMe or CH3CH(SnPh3)CH2COO–n-C6H13).
Substituent Effects in the Decomposition of t-Alkyl t-Butyl Peroxides
Authors: Matsuyama Kazuo , Higuchi Yoshiki
Published: July 2006

The decomposition rates and products of various t-alkyl t-butyl peroxides were examined in cumene at several temperatures. The decomposition of these peroxides took place homolytically, depending on the structure of the t-alkoxyl moieties (RC(CH3)2–O), and was retarded in the order: R=(CH3)3CCH2>(CH3)2CH>CH3CH2CH2>PhCH2>CH3CH2>ClCH2>CH3. The rate constants for the electron-donating alkyl substitutents at 150 °C are correlated very well to a Taft equation (logkd=−10.93 Σσ*−6.61 (correlation coefficient of 0.9501)), which is fairly different from the equation logkd=−10.131 Σσ*−3.422 for electorn-withdrawing polar substituents. From this correlation and a product analysis, the nature of the polar character at the transition state of the decomposition is discussed.
Reforming of Ethanol –Dehydrogenation to Ethyl Acetate and Steam Reforming to Acetic Acid over Copper-Based Catalysts–
Authors: Iwasa Nobuhiro , Takezawa Nobutsune
Published: July 2006

The title reactions, 2CH3CH2OH→CH3COOC2H5+2H2 and CH3CH2OH+H2O→CH3COOH+2H2, were carried out over copper-based catalysts (Cu, Cu/SiO2, Cu/ZrO2, Cu/Al2O3, Cu/MgO, and Cu/ZnO). The selectivities to ethyl acetate and acetic acid markedly depended upon the supports used. Acetaldehyde was formed by the dehydrogenation of ethanol and transformed to either ethyl acetate or acetic acid through steps in which a nucleophilic addition of ethanol (or ethoxide ions) or water (or hydroxide ions) to acetaldehyde occurred. The rates of the transformation steps to ethyl acetate and acetic acid were appreciably affected by the kinds of supports used. The transformation steps proceeded slowly, compared with the dehydrogenation step.
Effect of Oxidants on the Oxidative Coupling of Methane over a Lead Oxide Catalyst
Authors: Asami Kenji , Shikada Tsutomu , Fujimoto Kaoru
Published: July 2006

Oxidative coupling of methane was studied over a PbO/MgO catalyst using a variety of oxidants such as N2O, NO, CO2, and SO2. While N2O showed both high activity and selectivity for the title reaction, NO produced CO2, exclusively. The coupling reaction was assumed to proceed via the redox cycle of Pb and PbO on each oxidant mentioned above. Carbon dioxide produced small amounts of C2 hydrocarbons and CO, while SO2, was inactive for the reaction. Oxygen, N2O, CO2 could oxidize the Pb/MgO which had been formed by the reaction of PbO/MgO with methane at 1023 K. Thus-prepared PbO/MgO produced C2 hydrocarbons from methane. Even NO, which gave no C2 hydrocarbons in the CH4–NO cofeed reaction, converted the Pb/MgO to PbO/MgO and the PbO/MgO gave C2 hydrocarbons exclusively upon reacting with CH4. NO seems to oxidize the methyl radical, which is an intermediate of the coupling reaction to CO2. The ineffectiveness of SO2 as an oxidant was attributed to the formation of PbS, which is inactive in the methane activation.
Solvatochromic Shift of Aromatic Ketyl Anions due to Hydrogen Bonding
Authors: Ichikawa Tsuneki , Ueda Ken-ichi , Yoshida Hiroshi
Published: July 2006

The electronic spectra of fluorenone radical anions generated by γ-irradiation at 77 K in glassy matrices of ethanol and ethanol–2-methyltetrahydrofuran mixtures have been measured for elucidating the mechanism of the spectral change due to solvation of the radical anions by alcohols. Three kinds of the radical anions are generated in the mixed solvent: the radical anions without hydrogen bond (ε=1.05×104 dm3 mol−1 cm−1 at λmax=568 nm), with one ethanol molecule (ε=0.67×104 dm3 mol−1 cm−1 at λmax=529 nm) and two ethanol molecules (ε=0.37×104 dm3 mol−1 cm−1 at λmax=448 nm) hydrogen-bonded through the π electron on the carbonyl oxygen. The spectral shift and the decrease of the molar extinction coefficient of aromatic ketyl radical anions are explained as due to the stabilization of a carbonyl antibonding n orbital by hydrogen bonding.
Surface and Subsurface Fluorometry under Normal Incidence Conditions
Authors: Wu Xing-Zheng , Kitamori Takehiko , Teramae Norio , Sawada Tsuguo
Published: July 2006

Laser induced fluorescence spectroscopy under normal incidence conditions has been applied to a thick film sample, and identification of surface and subsurface fluorescent components was demonstrated. A model film sample adsorbing different fluorescent compounds on its two sides was prepared. Fluorescence spectra from the surface and subsurface regions were separately obtained for observation angles larger and smaller than the critical angle, and it was shown that the same information as the conventional attenuated total reflection method can be obtained with the normal incidence conditions, which is anticipated by the reciprocal principle. Dependence of fluorescence intensity on observation angle agreed well with theoretical calculation results based on the reciprocal principle, which supports the methodology propriety.
Characteristics of Suspended Ru/Carbon Catalyst for 2-Propanol Dehydrogenation Applicable to Chemical Heat Pump
Authors: Yamashita Masaru , Kawamura Tokiji , Suzuki Minoru , Saito Yasukazu
Published: July 2006

Liquid-phase dehydrogenation of (CH3)2CHOH, (CH3)2CHOD and (CH3)2CDOH was performed at 82.4 °C with high activity and selectivity under refluxing conditions by heating the suspended solution at 100 °C with a carbon-supported ruthenium catalyst. Since the mixture of (CH3)2CHOH and (CD3)2CO(10 vol%) gave 2-propan-1,1,1,3,3,3-d6-ol at a rate 7.15-times higher than that of hydrogen evolution, hydrogen transfer from 2-propanol to acetone ought to proceed simultaneously with dehydrogenation. Relatively small kinetic isotope effects of 1.69 and 1.57, obtained from (CH3)2CHOD and (CH3)2CDOH, respectively, on the Ru/carbon catalyst for dehydrogenation, suggests that the slowest step is not a splitting of the methine C–H bond but, rather, the formation of molecular hydrogen from surface hydrogen species. Further improvements regarding easy desorption of both acetone and hydrogen are necessary for the catalyst most suitable for 2-propanol dehydrogenation in a chemical heat pump system.
Photochemical Reactions of Vinyl-, Styryl-, and Benzyl- Substituted Digermanes
Authors: Mochida Kunio , Kikkawa Haruhiko , Nakadaira Yasuhiro
Published: July 2006

Photochemical reactions of vinyl-, styryl-, and benzyl-substituted digermanes were investigated by chemical trapping experiments. Photolysis of vinylpentamethyldigermane afforded 1-trimethyl-2-(pentamethyldigermyl)ethane as a major product, and styrylpentamethyldigermanes gave mainly styryltrimethylgermane. On the other hand, photolysis of benzyl-substituted digermanes (benzylpentamethyldigermane and 1,2-dibenzyltetramethyldigermane) gave hydrogermanes and hydrodigermanes as main products, respectively. These products were derived from germyl radicals generated by photoinduced homolysis of the germanium–germanium bond. In carbon tetrachloride (CCl4), these germyl radicals were converted to the corresponding chlorogermanes by abstraction of a chlorine atom. Germylene species were also to be evolved from such photolyses.
Synthetic Photochemistry. LVII. Facile Photochemical Construction of Hexahydro-as-indacene Skeleton, a Carbon Framework of Ikarugamycin, from High-Pressure Diels–Alder Adducts of Tropones–Cyclopentenone
Authors: Li Zhi-Hong , Mori Akira , Kato Nobuo , Takeshita Hitoshi
Published: July 2006

The high-pressure Diels–Alder reaction of tropones with 2–cyclopenten-1-one afforded isomeric mixtures of adducts. Upon UV irradiation, these adducts isomerized to hexahydro-as-indacene, via [1,3] acyl migration, and tetracyclo[7.3.0.03,7.06,8]undecene derivatives through a ketene intermediate via a di-π-methane rearrangement. The former tricyclic system corresponds to the carbon skeleton of ikarugamycin. An “exo [6+4] adduct” of tropone and 1,4-cyclopentadien-1-ol, an enol form of 2-cyclopentenone, was obtained as a by-product.
High-Pressure Fourier Transform Infrared Spectroscopy Study of the Diels–Alder Reaction of Isoprene and Maleic Anhydride in Supercritical Carbon Dioxide
Authors: Ikushima Yutaka , Saito Norio , Arai Masahiko
Published: July 2006

A high-pressure FTIR spectroscopy was used to make an in situ study on the Diels–Alder reaction of isoprene and maleic anhydride catalyzed with aluminum chloride in supercritical carbon dioxide at 306 K and 7.45 and 7.85 MPa, suggesting a two-step mechanism and showing a pressure effect.
Dielectric Properties of Poly(methylphenylsilylene) under Humidity in the Kilohertz Range
Authors: Awano Hiroshi , Iwai Takayoshi , Ohigashi Hiroji
Published: July 2006

The capacitance and dielectric loss tangent of poly(methylphenylsilylene) thin films were measured under various humidities over the frequency range 0.1–1000 kHz. In the high-humidity range, both the quantities increase with decreasing frequency. The existence of an anomalously low-frequency relaxation (lower than 0.1 kHz) is suggested in which the adsorbed water molecules are involved.
Glucose-Sensing Electrode Based on Carbon Paste Containing Ferrocene and Polyethylene Glycol-Modified Enzyme
Authors: Mizutani Fumio , Yabuki Soichi , Okuda Atsushi , Katsura Tatsuo
Published: July 2006

An amperometric glucose-sensing electrode is constructed by the use of a carbon paste containing 1,1′-dimethylferrocene and a polyethylene glycol-modified glucose oxidase. The polymer-modified enzyme is soluble in organic solvents (e. g., hexane) as well as in water, and exhibits a much higher activity than native enzyme does on the surface of a hydrophobic carbon paste eletrode. The higher enzyme activity results in an enhanced electrode response: the current response to glucose on the modified enzyme-based electrode is several times as large as that obtained on a native enzyme-based electrode.
Photoinduced Cyclization of 2-Acetonyl-3-alkoxy-1,4-naphthoquinones: Formation of 2-Alkyl-Substituted 4-Methylnaphtho[2,3-d]-1,3-dioxepin-6,11-diones
Authors: Nakagawa Katsuhiko
Published: July 2006

Irradiation of 2-acetonyl-3-alkoxy-1,4-naphthoquinones in benzene gave 2-alkyl-substituted 4-methylnaphtho[2,3-d]-1,3-dioxepin-6,11-dione and 2-acetonyl-3-hydroxy-1,4-naphthoquinone via intramolecular hydrogen-abstraction reaction. Irradiation of quinones in methanol, however, gave the latter product exclusively.
The Synthesis and Thermal Reorganization of Lithium Heptasodium cyclo-Octaphosphate
Authors: Watanabe Makoto , Honda Tomohiko , Furuta Shinsaku
Published: July 2006

Lithium heptasodium cyclo-octaphosphate hexahydrate, LiNa7P8O24·6H2O, has been prepared by heating lead cyclo-tetraphosphate tetrahydrate at 340°C for 20 min, dissolving the thermal product in a 3% aqueous solution of tetrasodium ethylenediammetetraacetate, and then crystallizing by the addition of lithium chloride and methanol to the solution. When the cyclo-octaphosphate was heated above 180°C, it decomposed to produce phosphates with chain lenghts shorter and longer than that of the cyclo-octaphosphate. The thermally produced phosphates were reorganized to sodium cyclo-triphosphate and a small amount of insoluble polyphosphates by heating at about 300 to 350°C. The phosphates melted at about 620°C.
Synthesis and Fluorescence Properties of Selectively Metallated Diporphyrins with Electron-Accepting Moieties
Authors: Nagata Toshi
Published: July 2006

Synthesis of selectively metallated diporphyrins with electron-accepting moieties is described. Steady-state fluorescence spectra of these compounds snowed substantial quenching of the fluorescence of the free-base porphyrin. A possible “superexchange” mechanism of long-range electron transfer is discussed.
Hydrates of Organic Compounds. XVI. Determination of the Melting Points and Hydration Numbers of the Hydrates of Tetrabutyl(or Tetraisopentyl)ammonium Alkanesulfonates
Authors: Nakayama Haruo , Yamanobe Masashi , Baba Kei
Published: July 2006

The solid-liquid phase diagrams of binary mixtures of water with tetraisopentylammonium alkanesulfonates, [(i-C5H11)4N][n-CnH2n+1SO3] (n=1–8), bis(tetrabutylammonium) alkanedisulfonates, [(n-C4H9)4N]2[O3S(CH2)nSO3](n=2–5), and with bis(tetraisopentylammonium) alkanedisulfonates, [(i-C5H11)4N]2[O3S(CH2)nSO3] (n=2–5), were examined in order to confirm the formation of hydrates. For all of the sulfonates examined the formation of hydrates has been newly confirmed. The hydrates of the tetraisopentylammonium alkanesulfonates have hydration numbers of around 37–40 and fairly high melting points (lie between 13 and 19°C). The typical hydrates formed by the bis(tetrabutylammonium) alkanedisulfonates have hydration numbers of around 52 and those by the bis(tetraisopentylammonium) alkanedisulfonates around 76. The former disulfonate hydrates have low melting points (between 1.0 and 10°C). However, the latter disulfonate hydrates have fairly high melting points (between 13 and 18°C). A salt with n=4 forms the most stable hydrate for both series of alkanedisulfonates. Judging from the hydration numbers and melting points, these hydrates seem to be clathrate-like.
A Further Modification of the Born Equation
Authors: Abe Takehiro
Published: July 2006

By considering the distance-dependent relative permittivity of a solvent, the Born equation has been modified for a diatomic ion in which the charge is located on an atom deviating from the center of a spherical cavity. The new equation has been successfully applied to the diatomic ions of OH−, SH−, and CN−.
Structural, Magnetic, and Spectroscopic Characterization of the Pyridine Complexes of Copper(II) Triphenylacetate: A Dimeric Copper(II) Triphenylacetate–Pyridine Complex with Distorted Trigonal Bipyramidal Geometry Around Copper
Authors: Steward Omar W , Kato Michinobu , Chang Shih-Chi , Sax Martin , Chang Chong-Hwan , Jury C Frederick , Muto Yoneichiro , Tokii Tadashi , Taura Toshiaki , Pletcher James F , Yoo Chung Soo
Published: July 2006

The synthesis and characterization of three copper(II) triphenylacetate-pyridine complexes are reported along with their magnetic and spectral properties: [Cu2(O2CCPh3)4(py)2]·C6H6 (1), [Cu2(O2CCPh3)4(py)2] (2), and Cu(O2CCPh3)2·2py (3). Crystal structure analyses of 1 and 3 have revealed unusual geometries around copper: 1, triclinic, space group P\bar1 with a=19.558(7) b=16.605(6), c=14.997(5) Å, α=14.55(2)°, β=97.11(2)°, γ=111.65(2)°, and Z=2; 3, monoclinic, space group P21⁄c with a=8.931(1), b=12.602(1), c=19.578(1) Å, β=118.17(0.4)°, and Z=2. The coordination sphere around each copper in the dimeric complex 1 is a highly distorted trigonal bipyramid with bridging triphenylacetato ligands spanning the apical and equatorial positions, resulting in a long Cu–Cu distance of 3.086(1) Å. Temperature-dependent magntic susceptibility measurements on 1 indicate that the two coppers are antiferromagnetically coupled with −2J=187 cm−1. The structure of the monomeric complex 3 is unusual in that the out-of-plane carboxylate oxygen is twisted 12° from the normal. Two solid modifications are observed for 2. The magnetic and spectral properties of 2a (−2J=173 cm−1) resemble those of 1, and 2b (−2J=321 cm−1) those of copper(II) acetate monohydrate. Magneto-structural correlations are presented. The novel structural features of these complexes are suggested to arise from steric effects resulting from the spatial relationships both between and within the molecules in the crystal environment.
Chromium(VI) Complexation with Triisooctylamine in Organic Solvents
Authors: Huang Yaou-Huei , Chen Chuh-Yung , Kuo Jen-Feng
Published: July 2006

Liquid–liquid extraction of chromium(VI) from chromic acid solutions with triisooctylamine (tris(6-methylheptyl)amine, abbrev. to TIOA) dissolving in various organic solutions has been studied. The reaction between chromium(VI) and TIOA in o-xylene has been discussed in detail. It has been found that dichromate ion and hydrogen chromate ion coexist in the system, based on the extraction data and the IR and UV-visible spectra of the TIOA-chromium salt. The chromium extraction equilibria can be expressed as:

‾TIOA+H++HCrO4−\ightleftarrows‾(TIOAH)HCrO4

2‾TIOA+2H++CR2O72\ightleftarrows‾(TIOAH)2CR2O7

The extraction constants are obtained.
Spectrophotometric Determination of Trace Amounts of Selenium Based on Catalytic Reduction of Toluidine Blue by Sulfide Ion
Authors: Parham Hooshang , Shamsipur Mojtaba
Published: July 2006

A simple, rapid, and sensitive kinetic method for the determination of trace selenium (0.03–1.5 μg cm−3) based on its catalytic effect on the reduction reaction of toluidine blue and sodium sulfide is reported. The reaction is monitored spectrophotometrically by measuring the decreasing absorbance of toluidine blue at 605 nm by the variable time method. The detection limit is 8 ng cm−3 and the relative standard deviation for 1 μg cm−3 selenium is 1.4%. The procedure was successfully applied to the determination of selenium in real samples.
Oxidation of Primary Alcohols over Hydrous Zirconium(IV) Oxide
Authors: Kuno Hideyuki , Shibagaki Makoto , Takahashi Kyoko , Matsushita Hajime
Published: July 2006

The oxidation of primary alcohols with quinone or benzophenone was carried out by catalysis with hydrous zirconium(IV) oxide in both batch and flow reaction systems. As a result, it was elucidated that a lot of primary alcohols can be efficiently oxidized over hydrous zirconium(IV) oxide.
Disproportionation of Carbon Monoxide on the Surface of Titanium and Vanadium Clusters
Authors: Srivastava Arun Kumar , Tewari Kamla Kant , Kojima Isao
Published: July 2006

In the framework of CNDO (Complete Neglect of Differential Overlap method) VOIP (Valance Orbital Ionization Potential) has been evaluated using the method of Anno and Sakai and for exchange integrals Wolfsberg–Helmholtz approximation has been used. The method has been used for studying the disproportiontion of carbon monoxide on titanium and vanadium clusters having two atoms respectively. A large number of theoretical models were designed, based upon various mechanistic possibilities. The bond energies between different atoms have been plotted against the distance, for the purpose of studying the formation and desorption of CO2. The present studies suggest that the disproportionation of CO on titanium cluster may follow a dissociative path while in case of vanadium cluster this reaction may follow a disproportionation, where disproportionation involves a reaction between a ‘bridge site’ adsorbed CO molecule with a gas phase CO molecule.
Effect of Proteins on the Zeta Potential of Dispersed Vesicular Globules in W/O/W Emulsions
Authors: Ueda Koichi , Matsumoto Sachio
Published: July 2006

The zeta potential of dispersed vesicular globules in W/O/W emulsions was found to be reduced systematically at neutral pH by increasing the isoelectric point of proteins immobilized in the inner aqueous phase of the globules. We considered the effect of proteins on the total interactions between vesicular globules.
1H and 13C NMR Relaxation Study of Iron(III) Tetraphenylporphyrin–Imidazole Complexes
Authors: Yamamoto Yasuhiko , Nanai Norishige , Chûjô Riichirô , Inoue Yoshio
Published: July 2006

1H and 13C nuclear relaxation of paramagnetic iron(III) tetraphenylporphyrin–imidazole complexes has been investigated in order to gain insight into the relationship between the paramagnetic relaxation rate and the electron-nucleus distance. The analysis of the nuclear spin–lattice relaxation time (T1) in terms of the distance indicated that, for the iron porphyrin complexes used, the contribution of the electron-nucleus dipolar coupling no longer contributes significantly to the relaxation process of a proton located at more than 0.75 nm away from the iron. For the complexes studied, the electron spin–lattice relaxation time (T1e) of 6.4 ps was calculated from the T1 values measured at 26°C.
Thermal Decomposition Studies on Amine Complexes of Copper(II) Nitrate in Solid State
Authors: Mathew Suresh , Nair C G R , Ninan K N
Published: July 2006

Thermal decomposition of tetraamminecopper(II) nitrate and bis(ethylenediamine)copper(II) nitrate has been studied using TG, DTG, and DTA. The kinetic parameters for the thermal deamination of the former were evaluated. The thermal decomposition of bis(ethylenediamine)copper(II) nitrate involves the concurrent deamination and the oxidation of the liberated amine by the decomposition products of Cu(NO3)2.
Estimation of Angles between the Ground- and Excited-State Dipole Moments from Solvent Spectral Frequency Shifts
Authors: Abe Takehiro
Published: July 2006

A method for estimating the angle between the ground- and excited-state dipole moments is presented on the basis of Abe’s improved expressions for the solvent frequency shifts of absorption and fluorescence spectra (Bull. Chem. Soc. Jpn., 54, 327 (1981); 58, 3415 (1985); 61, 3797 (1988)). Applications of the method to N,N-dimethylaniline and aniline give angles of 39.5° and 40.0°, respectively; the excited-state dipole moments are both smaller than the corresponding ground-state dipole moments.
Asymmetric Transformations of Proline and 2-Piperidinecarboxylic Acid via Formation of Salts with Optically Active Tartaric Acid
Authors: Shiraiwa Tadashi , Shinjo Kazuyuki , Kurokawa Hidemoto
Published: July 2006

The rates of racemization of optically active proline [Pro] and 2-piperidinecarboxylic acid [Pia] by using aldehydes as a catalyst tended to increase with a decrease in the acidity of the carboxylic acid used as solvent. Based on these results, the asymmetric transformations of Dl-Pro and (RS)-Pia were carried out via formation of salts with (2R, 3R)-tartaric acid to give optically pure l-Pro in over 80% yield and (R)-Pia in 70% yield. The asymmetric transformation of l-Pro was more successfully achieved by using (2S, 3S)-tartaric acid to give optically pure d-Pro in 85% yield based on the starting l-Pro.
Synthesis of Allyl 3-Deoxy-d-manno-2-octulopyranosidic Acid 4- and 5-Phosphates
Authors: Fukase Koichi , Kamikawa Takashi , Iwai Yukari , Shiba Tetsuo , Rietschel Ernst Theodor , Kusumoto Shoichi
Published: July 2006

Allyl glycosides (ketosides) of pyranosidic 3-deoxy-d-manno-2-octulosonic acid (Kdo), phosphorylated at either positions 4 or 5 were synthesized with the aim to study the biological properties of phosphorylated Kdo. The α and β-allyl glycosides prepared from a pyranosidic fluoride of diisopropylidene Kdo were protected at the 7- and 8-positions, and then O-phosphorylated at the 4- or 5-position by the phosphoramidite procedure. Separation of the positional isomers followed by deprotection afforded four compounds in pure states.
Preparation of New Nitrogen-Bridged Heterocycles. 28. First Syntheses of 1,3-Oxazino[6,5-b]indolizine Derivatives
Authors: Kakehi Akikazu , Ito Suketaka , Sakurai Tosio , Urushido Kunio , Hatanaka Susumu , Sugiura Kouji
Published: July 2006

The reactions of 2-[mercapto(methylthio)methylene]-2(3H)-indolizinones with alkyl isothiocyanates in the presence of potassium t-butoxide in N,N-dimethylformamide afforded new heterocycles, 3-alkyl-2H-1,3-oxazino[6,5-b]indolizine-2,4(3H)-dithione derivatives, in moderate yields. On the other hand, their reactions with phenyl isothiocyanate did not afford the corresponding 2H-1,3-oxazino[6,5-b]indolizine-2,4(3H)-dithiones, although the reaction of 2-[mercapto(methylthio)methylene]-1-methyl-2(3H)-indolizinone with phenyl isothiocyanate gave 10-methyl-3-phenyl-2-phenylimino-2,3-dihydro-4H-1,3-oxazino[6,5-b]indolizine-4-thione in a very low yield (10%). The structures of these 2H-1,3-oxazino[6,5-b]indolizine-2,4(3H)-dithiones and the 2-phenylimino analogue were determined by inspections of their physical and spectral data and by a single crystal X-ray analysis of one of these compounds.
Stereoselectivity in the Hydrogenation of 4-t-Butylcyclohexanone with Catalytically-Active Powder Electrodes
Authors: Senda Yasuhisa , Tateoka Minako , Itoh Hiroki , Ishiyama Jun-ichi
Published: July 2006

The electrocatalytic hydrogenation of the title compound was examined over Raney Ni, Raney Co, Pt-carbon and Pd-carbon as hydrogen-active powder electrodes. A high conversion of ketone to alcohol was observed on the Raney catalysts when the pKa values of the proton sources employed were around 5. The metal-on-carbon catalysts showed a relatively low conversion of ketone regardless of the proton sources. The stereochemistry of the reaction was examined.
Proton ENDOR Studies on Zinc-Doped Copper(II) Acetate Monohydrate Single Crystal
Authors: Kita Shouich , Uchida Kengo , Miyamoto Ryo , Iwaizumi Masamoto
Published: July 2006

The proton ENDOR spectra of the zinc-doped copper(II) acetate monohydrate single crystal were measured at 20 K. Hyperfine coupling tensors have been determined for the two protons of the water molecule at the axial position of the paramagnetic copper ion and a proton of the water forming the hydrogen bond with carboxylate oxygen at the equatorial plane of the copper ion. The axial water protons have small positive isotropic hyperfine couplings owing to the pseudo-contact interaction, and the equatorial water proton has a small negative one due to the spin polarization effect of the positive spin on the acetate oxygen through the hydrogen bond. The anisotropic hyperfine tensors of the former protons are interpreted by the dipolar interaction with the unpaired spin on the copper dx2−y2 orbital. The anisotropic interaction of the latter protons indicates that the spin delocalizes onto the oxygen atoms of the acetate bridges. Based on these observed hyperfine interactions, the mechanism of the spin–spin interaction in the dimer complex is discussed.
Intersystem Crossing of Radical Pair in Solvent Cage. External Heavy Atom Effect on Dual Photoreactions of Phthalazine
Authors: Inoue Hiroyasu , Sakurai Tadamitsu , Hoshi Toshihiko , Okubo Jun , Ono Isao
Published: July 2006

The effects of the temperature, initial concentration, and chemical quenchers on dual photoreactions of phthalazine were investigated. The results give further supporting evidence for a previously proposed reaction mechanism, i.e., phthalazine in the lowest excited singlet and triplet states affords singlet and triplet radical pairs, respectively, in the initial hydrogen abstraction process from 2-propanol. The singlet radical pair gives a reduction product in a solvent cage, whereas the radicals produced in the triplet state escape from the solvent cage, causing dimerization. On the basis of the reaction mechanism of dual photoreactions, external heavy-atom effects on the radical pairs within a solvent cage have been studied. The results indicate that heavy-atom perturbations bring about an enhancement of the intersystem crossing efficiency from the triplet-state radical pair to the singlet one, including a spin inversion of the radical pair in the solvent cage, rather than S1→T1 intersystem crossing induced within a single molecule of phthalazine.
Four- and Five-Coordinated Nickel(II) Isocyanide Complexes and Donor–Acceptor Complexes Containing Nickel and Mercury
Authors: Yamamoto Yasuhiro , Ehara Kazuko , Takahashi Katsuo , Yamazaki Hiroshi
Published: July 2006

Reaction of NiI2(RNC)2 (1) (a: R=2,6-Me2C6H3; b; 4-Br-2,6-Me2C6H2; c: 2,4-t-Bu2-6-MeC6H2: d: 2,4,6-t-Bu3C6H2 with RNC or PPh3 gave NiI2(RNC)3 (2) or NiI2(PPh3) (RNC)2 (3) (a: R=2,6-Me2C6H3; b: 2,6-Me2-4-BrC6H2). An X-ray analysis of (3a) showed that the complex has a trigonal bipyramidal structure; crystal data: Space group Pna21; a=21.577(2), b=9.440(1), c=17.075(1) Å, α=β=γ=90.0°, V=3477.7(6) Å3, R=0.0444. The bromide and chloride complexes, NiX2(2,6-Me2C6H3NC)2 (1e: X=Cl; 1f: X=Br) did not produce five-coordinated species. When complexes (1a, 1b, 1e, or 1f) were treated with Hg in the presence of isocyanide, the donor–acceptor complexes [Ni(RNC)4HgX2]2 (X=I, Br, or Cl) (4) were formed. An X-ray analysis of (4b) (R=4-Br-2,6-Me2C6H2) was undertaken; crystal data: Space group: Pl (triclinic); a=12.709(3), b=16.145(3), c=12.614(3) Å, α=96.11(2), β=107.67(2), γ=73.11(2)°, V=2359.5(10) Å3, R=0.0686. The complex is a donor-acceptor complex containing the Ni–Hg bond and has a dimeric structure bridged by two I atoms. The configuration around Ni is the trigonal bipyramid and around Hg, distorted tetrahedron.
Effect of Alkylammonium Ions on the Photochemical Behaviors of γ-Stilbazolium Aggregates in Clay Interlayers
Authors: Usami Hisanao , Takagi Katsuhiko , Sawaki Yasuhiko
Published: July 2006

Effect of alkylammonium ions (Cn+) has been studied on the clusterization and photochemical behaviors of γ-stilbazolium (4-(2-phenylvinyl)pyridinium) ion (1) adsorbed on clay interlayers. The aggregates of 1 were shown to be dissociated by the coadsorption of Cn+ with molecular length longer than that of 1. The major photoreaction was changed from cyclodimerization to E–Z isomerization on coadsorbing Cn+’s longer than 1. The efficient excimer emission from intercalated 1 was dramatically reduced by coadsorbing alkylammonium ions. The resulting concentration dependence of excimer emission intensity is nicely simulated by a Monte Carlo method for two-dimensional lattice site models.
Ion Pairing of Radical Ions of Aromatic Alkenes and Alkynes Studied by Pulse Radiolysis
Authors: Yamamoto Satoshi , Yamamoto Yukio , Hayashi Koichiro
Published: July 2006

Pulse radiolysis of 1,2-dichloroethane solutions of trans,trans-1,4-bis(2-phenylethenyl)benzene and 1,4-bis(2-phenylethynyl)benzene was undertaken in the presence of Bu4NPF6 (Bu=butyl) to investigate the effect of ion pairing of the solute radical cations with PF6−. It was also undertaken for the tetrahydrofuran solutions of the above compounds in the presence of Bu4NPF6 and NaBPh4, where the solute radical anions are generated and form ion pairs with Bu4N+ and Na+. The decay of the radical ions, which is due to neutralization, is retarded by the ion pairing. The rate constants for the neutralization reactions in the free-ion and ion-paired states were determined. Also presented are the data for the radical ions of trans-stilbene, diphenylacetylene, trans,trans-1,4-diphenyl-1,3-butadiene, and diphenylbutadiyne. The radical ions of the aromatic alkynes are less stabilized by the ion pairing than those of the aromatic alkenes having the same carbon skeletons probably because of more extensive charge delocalization of the former radical ions. Spectral shifts to shorter wavelengths caused by the ion pairing are appreciable for the radical anions. Dependence of the spectral shifts on the size of the radical anions is described.
Preparation and Properties of Oxo-Centered Trinuclear Chromium(III) Complexes with Bridging Optically Active Amino Acids, [Cr3(μ3-O)(μ-O,O′-amino-acid)6(H2O)3]7+
Authors: Kato Hisashi , Nakata Kou , Nagasawa Akira , Yamaguchi Tadashi , Sasaki Yoichi , Ito Tasuku
Published: July 2006

Trinuclear chromium(III) complexes with optically active amino acids as bridging groups, [Cr3(μ3-O)(μ-RCH(NH3)COO)6(H2O)3]X7 (R=CH3, (CH3)2CH, (CH3)2CHCH2, C6H5CH2; X=Cl−, NO3−), were prepared, and the X-ray structure of the l-valine complex was determined. Their electronic spectra and magnetic moments are similar to those of analogous carboxylate-bridged trichromium(III) complexes.
Alumina-Catalyzed Addition of Thiols to Methyl Propiolate
Authors: Kodomari Mitsuo , Saitoh Goroh , Yoshitomi Suehiko
Published: July 2006

The addition of thiols to methyl propiolate was remarkably accelerated in the presence of alumina to give the Z-isomer of the 1:1 adducts stereoselectively, in which alumina acts as a bifunctional catalyst of acid and base.
Solvent Effect on the ESR Parameters of Di-t-butyl Nitroxide and Galvinoxyl. Theoretical Application of the MNDO Effective Charge Model
Authors: Takase Hideto , Morihashi Kenji , Kikuchi Osamu
Published: July 2006

An effective charge model of the solvent effect was incorporated with the RHF-MNDO-CI method for free radicals, allowing the solvent effect on the hyperfine coupling constants (hfcc) and g-values of the di-t-butyl nitroxide (DTBN) and galvionxyl radicals to be examined. The calculated solvent dependences of the spin distribution and the n→π* excitation energy of DTBN have well elucidated the observed solvent effect on the hfcc and g-value of DTBN. The observed trend for the proton hfcc of galvinoxyl has been correctly reproduced by the present theoretical model.
Synthesis and Properties of Peroxy Esters Having a Benzophenone Chromophore
Authors: Kumura Hiromi , Nakamura Tomoyuki , Higuchi Yoshiki , Suyama Shuji
Published: July 2006

Diperoxy esters having a benzophenone chromophore have been successfully synthesized from the reaction of 3-chloro-3-phenylphthalide (1) with 2,5-dihydroperoxy-2,5-dimethyl-3-hexyne (4a) or 2,5-dihydroperoxy-2,5-dimethylhexane (4b). The corresponding diperoxy esters had a UV absorption above 300 nm. The free radicals produced during the photolysis of these compounds initiated the radical polymerization of methyl methacrylate at room temperature under UV light.
Studies on the Secondary Structure of Bradykinin in Aqueous Solution. Syntheses, Circular Dichroism Spectra, and Biological Activities of Bradykinin Amide and [d-Ala4]-Bradykinin
Authors: Hashimoto Chikao , Nozaki Sukekatsu , Muramatsu Ichiro
Published: July 2006

Bradykinin amide and [d-Ala4]-bradykinin were synthesized by the ‘hold-in-solution’ method. The circular dichroism spectra of both peptides were measured and compared with that of bradykinin. These analogs exhibited weak activity (0.01% of bradykinin) in the increment of blood flow in a femoral artery of dog.
Synthesis, Chemical Properties, and Structure of a Sterically Hindered Ketone, 2,2,5,5-Tetramethyl-4,4-diphenyl-3-thiolanone
Authors: Nakayama Juzo , Hirashima Atsushi , Yokomori Yoshinobu
Published: July 2006

A sterically hindered ketone, 2,2,5,5-tetramethyl-4,4-diphenyl-3-thiolanone (1), was synthesized in two steps starting from 2,2,4,4-tetramethyl-1,5-diphenyl-3-thiapentane-1,5-dione. The carbonyl group of 1 is unreactive toward a series of nucleophiles which are bulkier than hydride or its equivalents. The observed unreactivity is ascribed to the steric hindrance enhanced by the two methyl groups on C-5 (“buttressing” effect). The result of an X-ray single crystal structure analysis of 1 is also described.
Molecular Motions of t-Butylammonium Ions and Structural Phase Transitions in Solid t-Butylammonium Perchlorate Studied by 1H NMR and Thermal Measurements
Authors: Ishida Hiroyuki , Iwachido Tadashi , Hayama Naomi , Nakamura Daiyu , Ikeda Ryuichi
Published: July 2006

Differential thermal analysis (DTA), differential scanning calorimetry (DSC), and the temperature dependences of the 1H spin-lattice relaxation time (T1) and the second moment (M2) of 1H NMR absorptions were studied in (CH3)3CNH3ClO4 and its partially deuterated analogs, (CH3)3CND3ClO4 and (CD3)3CNH3ClO4. DTA and DSC studied revealed four solid phases, including a metastable phase, in the temperature range between 80 K and the melting point (414 K). The stable phases (named as I, II, and III) were obtained above 394 K, between 394 and 327 K, and below 327 K, respectively. The metastable phase II′, prepared by rapid cooling the phase II to ca. 100 K, exists below ca. 245 K. The cationic motions in each solid phase were studied by T1 and M2 experiments. Three kinds of motions (reorientations of the CH3 groups about their C–C bond axes, the NH3+ group about its C–N bond axis, and the t-butyl group about the C–N bond axis) were observed in these phases and their motional parameters were determined