bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis of Naphthoquinone Derivatives. XIII. Reaction of 2,3-Dihydro-2-thioxo-1H-naphth[2,3-d]imidazole-4,9-dione with Dimethyl Acetylenedicarboxylate
Authors: Nakamori Tateo , Saito Toshiyuki , Kasai Toshiyasu
Published: July 2006

Tetracyclic compounds with a thiazolidinone or thiazinone ring fused to 1H-naphth[2,3-d]imidazole-4,9-dione were synthesized. Dimethyl 2-(4,9-dioxo-4,9-dihydronaphth[2,3-d]imidazol-2-ylthio)fumarate (3) was obtained by a reaction of 2,3-dihydro-2-thioxo-1H-naphth[2,3-d]imidazole-4,9-dione with dimethyl acetylenedicarboxylate in methanol. A ring-closure reaction of 3 in acetic anhydride was found to give selectively methyl (3,5,10-trioxo-2,3,5,10-tetrahydronaphth[2′,3′ : 4,5]imidazo[2,1-b]thiazol-2-ylidene)acetate, while, the cyclization of 3 in polyphosphoric acid afforded methyl 4,6,11-trioxo-6,11-dihydro-4H-naphth[2′,3′ : 4,5]imidazo[2,1-b]thiazine-2-carboxylate.
Synthesis of (S)- and (R)-3-Hydroxy-4-butanolide and (2S,4S)-, (2R,4S)-, (2S,4R)-, and (2R,4R)-2-Hydroxy-4-hydroxymethyl-4-butanolide and Their Satiety and Hunger Modulating Activities
Authors: Uchikawa Osamu , Okukado Nobuhisa , Sakata Toshiie , Arase Koichi , Terada Kenji
Published: July 2006

Two endogenous γ-lactones, 3-hydroxy-4-butanolide (1) and 2-hydroxy-4-hydroxymethyl-4-butanolide (2) have been identified as substances that enhance, respectively, satiety and hunger by their effects on the feeding behavior and the central neurons of rats. To determine the stereochemistry of the physiologically active isomers, all the stereoisomers of these two lactones were synthesized and their effects on the feeding behavior and humoral factors were assessed by infusion into the rat third cerebroventricle. Among four isomers, (2S,4S)-2-hydroxy-4-hydroxymethyl-4-butanolide (2a) was most effective in elicitating the feeding and caused potent hypoglycemia with hyperinsulinemia. (S)-3-Hydroxy-4-butanolide (1a) suppressed the food intake more potently than the antipode and caused humoral responses reciprocal to those of 2a. From these facts, it was concluded that 1a and 2a are physiologically active forms for conveying intrinsic signals of satiety and hunger to neurons in the hypothalamus.
Studies on Synthetic Ionophores. VI. Synthesis of Polyether Carboxylic Acids and Their Use as Carriers for Alkali Metal Ion Transport through Liquid Membrane
Authors: Yamaguchi Kazuo , Negi Shigeto , Kozakai Shohei , Nagano Roichi , Kuboniwa Hitoshi , Hirao Akira , Nakahama Seiichi , Yamazaki Noboru
Published: July 2006

ω-Hydroxy carboxylic acids (3, 5, 6, 7, 10, 12, 14, 17, 18, 20, and 22) bearing 2–6 ether oxygens and aromatic rings with or without a tetrahydrofuran ring and the ω-methoxy and ω-benzyloxy derivatives of 5 (8 and 9) were synthesized. These were employed as carriers for active and competitive transport of alkali metal ions through liquid membrane as well as for extraction of alkali metal ions to organic layers. Effect of hydrophobic group of aromatic and tetrahydrofuran rings, number of ether oxygens, and terminal hydroxyl group of the ionophores on the ion transport ability and selectivity were investigated. The hydrophobic groups increased total amount of transported ions as well as partition coefficients. The ionophore, 5, which contains five ether oxygens, two aromatic rings, and o-toluic acid moiety transported K+ selectively over Na+ and Li+ through 1,2-dichloroethane being consistent with the extraction experiments. The m- and p-substituted isomers, 6 and 7, exhibited no transport ability through 1,2-dichloroethane. The ω-alkoxy derivatives of 5 (8 and 9) exhibited less selectivity for K+ through 1,2-dichloroethane than 5 did. Through 1-hexanol, the ionophores, 5–9, including linoleic acid with no ether linkage transported alkali metal ions. The ionophores (3, 12, 20, and 22) containing 2–4 ether oxygens did not exhibit high transport ability.
Determining Factors for the Product Para/Ortho Ratio and Reaction Rate in the Formation of (Hydroxymethyl)phenols from Phenol and Formaldehyde
Authors: Komiyama Makoto
Published: July 2006

Formations of 2- and 4-(hydroxymethyl)phenols from phenol and formaldehyde in aqueous alkaline solutions were kinetically investigated by the use of HPLC. The para/ortho ratio for the products sigmoidally increased with increasing concentration of sodium hydroxide, whereas the total yield of the (hydroxymethyl)phenols showed a steep maximum at the charged molar ratio unity of sodium hydroxide to phenol. Use of lithium hydroxide and potassium hydroxide, in place of sodium hydroxide, as alkaline catalysts results in almost the same para/ortho ratios. The addition of potassium chloride and magnesium sulfate decreased both the para/ortho ratio and the yield. These results indicate that the reactions proceed via an electrophilic attack of formaldehyde, which is free from the adduct formation with hydroxide ion, at phenolate ion. Electrostatic interactions between the phenoxide oxygen atom of the phenol and the incoming hydroxymethyl residues in the transition state exhibit a predominant role in the determination of the para/ortho ratio.
Syntheses and Cytotoxicity of the AB-, C-, and BC-Ring Systems of Sesbanimides
Authors: Matsuda Fuyuhiko , Ohsaki Masako , Yamada Kaoru , Terashima Shiro
Published: July 2006

Preparation of some AB-ring systems 5 and 8 of sesbanimides 1 and 2, potent antitumor alkaloids, were performed starting from the synthetic intermediates of our first total synthesis of 1 and 2. The C-ring systems 14a–d were synthesized by applying the previously explored novel Reformatsky reaction to various aldehydes. The optically active BC-ring systems 20 and 21 having the same absolute configurations as those of 1 and 2, were derived from (−)-2,4-O-methylene d-sorbitol (15) as the B-ring synthon. Since all of these compounds 5, 8, 14a–d, 20, and 21 and the previously synthesized AB-ring system 3 showed no significant in vitro cytotoxicity against P388 murine leukemia, its appeared evident that 1 and 2 exhibit their notable antitumor activity owing to cooperation of the A- and C-rings.
Ultrasonic Investigation on the Structure of Aqueous Solution of 2-Butanone
Authors: Ramanjappa T , Rajagopal E
Published: July 2006

The effect of 2-butanone on the temperature corresponding to adiabatic compressibility minimum (TACM), sound velocity maximum (TSVM) and specific acoustic impedance maximum (TSAIM) of pure water has been studied by experimentally determining the sound velocity and density of aqueous solution at different concentrations over a temperature range 34–70.5 °C. The structural contribution to the shift in TACM, TSVM, and TSAIM has been evaluated. The shift is positive throughout the concentration range studied and indicates that 2-butanone is hydrophobic in nature.
Ion-Exchange Properties of Niobium(V) Materials. II. Synthesis and Characterization of Crystalline Niobium(V) Phosphate
Authors: Qureshi Mohsin , Gupta Jai Prakash , Khan Hina , Ahmad Anees
Published: July 2006

An attempt has been made to synthesize and characterize the crystalline niobium(V) phosphate. The characterization was done on the basis of pH titration, X-ray, XPS, TGA, DSC, and IR studies. It is an ion exchange material which shows about 20% higher chemical stability over the amorphous niobium(V) phosphate. It was found to have a pseudocubical unit cell structure with a0(H)=10.244 Å and a stiff three dimensional zeolytic structure. The empirical formula of the compound was obtained as Nb2O5·1.5 P2O5·7.5 H2O. The proposed chemical formula is (NbO)2(HPO4)3·6H2O (d110=7.23 Å). The exchanger is monofunctional in nature having the maximum exchange capacity of 4.6 meq g−1 for potassium ion at pH 8.5
Photoresponsive Peptide and Polypeptide Systems. VI. Reversible Solubility Change of Azo Aromatic Lysine
Authors: Yamamoto Hiroyuki , Nishida Ayako
Published: July 2006

The reversible solubility change of azo aromatic lysines due to the trans–cis photoconversion of azo moieties was studied. On irradiation at different wavelengths, azo aromatic lysines are soluble under ultraviolet light (cis) and precipitate under visible light (trans). The dipole moments of the solvents used are considered to play a role in the solubility change.
X-Ray Structure Determination and NMR Characterization of Some Fused Heterocycles with a 1,3,5-Triazine-2,4(1H,3H)-dione Ring. Reaction of 2-Amino-4(3H)-pyrimidinone with Chloroformyl Isocyanate
Authors: Sawada Masami , Tanaka Takanori , Furukawa Yoshiro , Toda Tomoki , Takai Yoshio , Hanafusa Terukiyo
Published: July 2006

The reaction product a of 2-amino-4(3H)-pyrimidinone with chloroformyl isocyanate was methylated and the two resulting products were determined as 4 (for the major product) and 5 (for the minor one) by X-ray crystal structure analyses. In a DMSO solution of a, the 2a tautomer was shown to be predominant by 13C NMR analysis.
The Synthesis of a Heavy-Atom Derivative of Gramicidin S (GS), [d-Phe(4-Br)4,4′]-GS, by a Novel Method
Authors: Aimoto Saburo
Published: July 2006

A new approach for the preparation of cyclic peptides was successfully applied to the synthesis of cyclo(–Val–Orn–Leu–d–Phe(4-Br)–Pro–Val–Orn–Leu–d–Phe (4-Br)–Pro–) ([d–Phe(4-Br)4,4′]-GS). [d–Phe(4-Br)4,4′]–GS showing antibacterial activity was obtained as crystals.
Syntheses and NMR Spectroscopic Studies on the Conformations of 1-[1-(2-Aralkyloxy- and 2-Acyloxyphenyl)vinyl]-1H-Imidazoles
Authors: Yamamoto Kazuko , Hamada Yoshiki , Takeuchi Isao , Suezawa Hiroko , Hirota Minoru
Published: July 2006

The title compounds were synthesized from 2-[1-(1-imidazolyl)vinyl]phenol and their conformations were discussed on the basis of their 1H and 13C NMR spectra.
Synthetic Photochemistry. XLI. Photorearrangement of 5-Alykyl-1-hydroxy-8-oxabicyclo[3.2.1]octa-3,6-dien-2-ones to 2-Alkyl-3-oxatricyclo[3.3.0.02,8]octane-4,6-diones
Authors: Mori Akira , Kasai Seishi , Takeshita Hitoshi
Published: July 2006

The irradiations of 5-alkyl-1-hydroxy-8-oxabicyclo[3.2.1]octa-3,6-dien-2-ones, either in benzene or methanol by means of a high-pressure mercury lamp produced 2-alkyl-3-oxatricyclo[3.3.0.02,8]octane-4,6-diones. Although the intermediate ketenes could be detected by low temperature NMR, no adduct was formed in protic solvents.
One Pot Synthesis of Dinuclear Tungsten(V) Compounds Containing [W2XY(μ-S)2]2+ (X=O,S; Y=O,S) Cores by Thermally Induced Internal Electron-Transfer Processes
Authors: Ansari Mohammad A , Chandrasekaran Jayanthi , Sarkar Sabyasachi
Published: July 2006

New synthetic methods for the preparation of dimeric tungsten(V) complexes are described containing the core [W2XY(μ-S)2]2+ (X=O,S; Y=O,S). The synthesized complexes have been characterized by a variety of spectroscopic techniques. [W2OS(μ-S)2(S2CNEt2)2] has been found to react with cyanide to give [W2O2(μ-S)2(S2CNEt2)2].
Synthesis and Properties of Three Sulfur-Containing Porphyrins, One Water-Soluble
Authors: Datta-Gupta Nirmalendu , Malakar Debasis , Jenkins Celestine , Strange Cynthia
Published: July 2006

Three new porphyrins with sulfur functional groups, one of which is water-soluble, have been prepared. Their UV-visible absorption, fluorescence emission, and 1H NMR spectra as well as their copper(2+) insertion kinetics, pK3 values and first and second reduction potentials determined. For the water soluble porphyrin, its binding with human serum albumin (HSA) determined.
Mixed Colloidal Dispersions of Silica and Hematite
Authors: Esumi Kunio , Idogawa Hiroyuki , Meguro Kenjiro
Published: July 2006

The colloidal behavior of mixed dispersions containing hematite (diameter=138.9 nm) and silica (diameter=7.0 nm) has been studied by measuring the stability ratio, zeta potential, and particle size. When various particle numbers of silica were added to a constant particle number of hematite, different colloidal behavior was observed, depending on the pH. In a pH region where the two solids were oppositely charged, hematite particles showed a dispersion-coagulation-redispersion process with increasing particle number of silica, resulting in a coating layer of silica particles on the hematite surface. On the other hand, in a region where both solids were negative, the addition of silica enhanced the stability of the hematite.
Characterization of Monomeric and Polymeric (Octacyanophthalocyaninato)metals in Thin Films
Authors: Yanagi Hisao , Ueda Yasukiyo , Ashida Michio
Published: July 2006

Thin films were prepared by the reaction of 1,2,4,5-tetracyanobenzene with Ni, Co, Fe, Zn films at various temperatures. The films were characterized by infrared, UV/visible and photoelectron spectroscopy and analytical electron microscopy in comparison with films prepared on substrates of a KCl single crystal and a Cu film. The films produced on the metal films below 400 °C were composed of tentacle-like crystals growing from the surface and an amorphous layer condensed over the metal substrate. The tentacle-like crystals were soluble in concentrated sulfuric acid and were identified as intercalation compounds of (octacyanophthalocyaninato)metal with the respective metal atoms. The amorphous layers contained polymerization products with a polynitrile structure, which were insoluble in concentrated sulfuric acid. The films produced on the metal films at 450 °C were composed of a thick layer and had a very limited solubility in concentrated sulfuric acid. They were ascribed to metal complexes of polyphthalocyanines(poly-M(Pc)) and cross-linked polymers with structure elements such as polynitrile and triazine.
Molecular and Crystal Structure of the Bilayer-Forming Lipid-Model Amphiphile, Ditetradecyldimethylammonium Bromide Monohydrate
Authors: Okuyama Kenji , Iijima Naomi , Hirabayashi Kiyoshi , Kunitake Toyoki , Kusunoki Masami
Published: July 2006

The conformation and molecular packing of ditetradecyldimethylammonium bromide monohydrate (2C14N+2C1Br−·H2O), C30H62NBr·H2O, has been determined by the X-ray diffraction method. The crystals are triclinic with the space group P\bar1, Z=2, a=2.9827(9), b=0.7847(3), c=0.7480(3) nm, α=104.69(4), β=90.64(7), and γ=90.84(6)°. The structure was determined by direct methods and refined by the least-squares procedure: R=0.07 (Rw=0.07) for 3335 observed reflections. Two amphiphile molecules of the unit cell are related by centrosymmetry and pack tail to tail in a bilayer structure. The hydrocarbon chains tilt about 45° with respect to the bilayer normal. There are statistically four water molecules with half occupancies in a unit cell. Water molecules and bromide anions make hydrogen-bonding networks along the c-axis in the hydrophilic layer. The above molecular and crystal structure of 2C14N+2C1Br−·H2O was quite similar to those of 2C18N+2C1Br−·H2O.
The Spectrofluorometric Determination of Anthraquinone with Hydroxylamine in the Dimethyl Sulfoxide Medium Containing Sodium Methoxide and Methanol
Authors: Tachibana Masaki , Furusawa Motohisa
Published: July 2006

Anthraquinone reacts with hydroxylamine in the dimethyl sulfoxide (DMSO) medium containing sodium methoxide and methanol. Since the reaction product is fluorescent in the medium, this reaction can be used for the fluorometric determination of anthraquinone. A DMSO solution of a sample was mixed with a DMSO solution of hydroxylamine hydrochloride and a methanolic solution of sodium methoxide. The mixture was then allowed to stand for 20 min at 60 °C in a volumetric flask with a tightly fitting stopper. After cooling and dilution to the mark with DMSO, the fluorescence intensity of the solution was measured at 597 nm, with excitation at 494 nm. The intensity was stable for at least 2 h in the tightly stoppered flask. The determination limit of anthraquinone was 100 ng. By the application of this spectrofluorimetry, anthraquinone in 9,10-phenanthrenequinone could be successfully determined over the content range from 0.2 to 4%.
Reaction of 1,1,2,2-Tetrachloro-2,2aα,4α,8bα-tetrahydrocydobuta[c]quinolin-3(1H)-one with Nucleophiles; Reaction, Product Structure, and Mechanism
Authors: Nonoyama Shinji , Yonezawa Noriyuki , Saigo Kazuhiko , Hasegawa Masaki , Hirano Tsuneo
Published: July 2006

2a-Substituted dichlorodihydrocyclobuta[c]quinolin-3(4H)-one (3) and trichlorovinyl-2-quinolone (4) were obtained from the cross photocycloadduct of 2-quinolone and tetrachloroethylene. The position of the substituent on 3 was determined from the NOE volumes in the NOESY spectrum in comparison with the AM1 geometries. The reaction of the photoadduct (1) with a base or nucleophile, yielding 3 and/or 4, was interpreted to proceed via a cyclobutene intermediate formation followed by an SN2′ displacement or [2+2] cycloreversion.
Synthesis of 1,10-Disubstituted 1,4,7,10,13,16-Hexaazacyclooctadecanes and Their Extractability for Metal Cations
Authors: Takada Masayuki , Saigo Kazuhiko , Hirai Teruhisa , Ohchi Ikuro , Tajima Masayuki , Seno Manabu , Hasegawa Masaki
Published: July 2006

1,10-Disubstituted 1,4,7,10,13,16-hexaazacyclooctadecanes (hexaaza-18-crowns) having lipophilic groups were synthesized from 1,2-ethanediamine as a starting material. Cyclization of 3,6-ditosyl-3,6-diazaoctanedioyl dichloride and 3,6-ditosyl-3,6-diazaoctane-1,8-diamine under the high dilution conditions, followed by diborane reduction of the amide carbonyl, gave the macrocyclic precursor. A series of reactions, i.e., acylation, diborane reduction, and detosylation, afforded 1,10-disubstituted hexaaza-18-crowns. Their extractability for metal cations was examined by spectrophotometric analysis. They showed relatively high extractability for Ag+, Zn2+, and Cd2+.
Reaction of Rifamycins with Sodium Sulfinates
Authors: Taguchi Masahiro , Aikawa Norio , Yoshida Kenzaburo , Kitamura Mikiya , Tsukamoto Goro
Published: July 2006

The reaction of rifamycin S and the quinonic 3-(hydrazonomethyl)rifamycin derivatives with sodium sulfinates under neutral conditions were found to afford the hydroquinone-type 4-O-sulfonyl derivatives of rifamycin. 3-Amino-4-deoxo-4-iminorifamycin S also gave rise to the hydroquinone-type 4-deoxy-4-sulfonylamino derivatives of rifamycin when treated with sodium sulfinates. Under acidic conditions, rifamycin S and 3-bromorifamycin S produced the hydroquinone- and quinone-type 3-sulfonyl derivatives of rifamycin, respectively, by reactions with sodium sulfinates. Some of sodium salts of 4-O-sulfonylrifamycin SV derivatives afforded rifamycin S and sodium sulfinates and/or sodium sulfonates when heated in AcOEt.
Synthesis of α-Helices Having a Positively Charged Random Coil-Block on Either N- or C-Terminal
Authors: Takahashi Sho , Hibino Takeshi , Sawada Seiji
Published: July 2006

To study a charge-induced stabilization of α-helix, α-helical peptides having a positively charged random-coil block on either N- or C-terminal of the helix, and having a strictly defined length, (Ala)20(X)20Phe and (X)20(Ala)20Phe (X=Lys or Orn), were synthesized. Component dipeptides were coupled on p-(oxymethyl)phenylacetamidomethyl polystyrene.
Synthesis of Isoindoles. Acid or Base Induced Cyclization of 2-Cyanobenzaldehyde with Alcohols
Authors: Sato Ryu , Ohmori Michiko , Kaitani Fumiko , Kurosawa Akiko , Senzaki Toshihide , Goto Takehiko , Saito Minoru
Published: July 2006

Various 3,3-dialkoxy-2,3-dihydro-1-hydroxy-1H-isoindoles (2) were obtained by treating 2-cyanobenzaldehyde (1) with alcohols in the presence of an acid catalyst such as silica gel. In the reaction using a base catalyst such as triethylamine and 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), 3-alkoxy-2,3-dihydro-1H-isoindol-1-ones (4) were formed via 3-alkoxy-1,3-dihydro-1-isobenzofuranimine (3). The use of 1,4-diazabicyclo[2.2.2]octane (DABCO) and N,N,N′,N′-tetramethylethylenediamine (TMEDA) gave 2 besides 3 and 4. A convenient and selective synthesis of isoindoles and its derivatives are described.
The Crystal and Molecular Structures of 2,2,4,6-Tetraphenyldihydro-1,3,5-triazine Acetone Solvate and 2-Propanol Solvate
Authors: Mori Yukie , Ohashi Yuji , Maeda Koko
Published: July 2006

The crystal and molecular structures of 2,2,4,6-tetraphenyldihydro-1,3,5-triazine acetone solvate (1) which turns red on exposure to UV light, and 2-propanol solvate (2) which shows no photocoloration, have been determined by the X-ray method. The crystals of both inclusion compounds are monoclinic. For 1 the space group is P21⁄n; Z=4, with a=16.385(2), b=11.987(2), c=12.939(2) Å, and β=92.24(2)°. For 2 the space group is C2⁄c; Z=8, with a=21.967(3), b=13.418(1), c=19.576(4) Å, and β=118.73(1)°. The final R values were 0.082 and 0.083 for 1 and 2 respectively. In both crystals, the dihydrotriazine ring exists in 2,3-dihydro form, which is one of the two possible tautomeric forms. In 1 each acetone molecule interacts with only one molecule of tetraphenyldihydrotriazine by N(3)–H(3)···O hydrogen bond, while in 2 tetraphenyldihydrotriazine and 2-propanol molecules are alternately connected by N(3)–H(3)···O and N(5)···H–O hydrogen bonds to construct a ribbon-like structure. It was suggested that the N(3)–H(3)···O–H···N(5) hydrogen bonds which exist in 2 but not in 1 inhibit photocoloration of 2.
Cycloaddition Reactions of Highly Stabilized Isoquinolinium Methylides to Nonactivated Olefins and Electron-Rich Olefins
Authors: Tsuge Otohiko , Kanemasa Shuji , Sakamoto Kazushige , Takenaka Shigeori
Published: July 2006

Highly stabilized isoquinolinium methylides bearing two electron-withdrawing substituents at the ylide carbon undergo cycloadditions with aryl-substituted olefins (acenaphthylene, (E)- and (Z)-stilbenes, indene, and styrene), alkyl-substituted olefins (norbornene, (Z)-3-hexene-1,6-dinitrile, 1-hexene, 2-propen-1-ol, and 3-(trimethylsilyloxy)propene), and electron-rich olefins (vinylene carbonate, butyl vinyl ether, and phenyl vinyl sulfide). These cycloadditions proceed in an exclusively regioselective and mostly stereoselective manner.
Crystal and Molecular Structure of Tetrabutylammonium Bis(1,4-dithiin-2,3-dithiolato)nickelate(III), (Bun4N)[Ni(ddt)2]
Authors: Kim Hyernjoo , Kobayashi Akiko , Sasaki Yukiyoshi , Kato Reizo , Kobayashi Hayao , Nakamura Tadashi , Nogami Takashi , Shirota Yasuhiko
Published: July 2006

The crystal structure of tetrabutylammonium salt of a new multi-sulfur 1,3-dithiolene complex, (Bun4N)[Ni(ddt)2] (ddt=1,4-dithiin-2,3-dithiolato) has been determined by the single-crystal X-ray diffraction technique. Crystals are monoclinic, space group C2⁄c, a=66.107(40), b=9.182(5), c=19.119(12) Å, β=147.29(3)°, V=6271(1) Å3, and Z=8. The structure was solved by the heavy atom method, and refined by a block-diagonal least-squares method to R=0.070. There are two crystallographically independent molecules of Ni(ddt)2, molecule-A and molecule-B. Molecule-B forms segregated uniform stacks along the b-axis. The (Bun4N)+ cations are located between two molecular planes of molecule-A. The Ni(ddt)2 molecules are almost planar except two terminal vinylene moieties, which are folded to opposite side each other and the folding angles of molecule-A and molecule-B are 28° and 39°, respectively.
Crystal Face Anisotropy of Propylene Oxidation on Molybdenum Trioxide
Authors: Oyama Shigeo Ted
Published: July 2006

Samples of MoO3 consisting of unsupported oriented crystallites exposing primarily the (010) plane and of randomly oriented powders were used to study the partial oxidation of propylene and allyl iodide. The materials were characterized by scanning electron microscopy, X-ray diffraction, infrared spectroscopy, laser Raman spectroscopy, temperature programmed desorption of ammonia and surface area measurements. The unoriented powders were twice as active as the oriented crystallites in the oxidation of propylene, but both were similar in activity in the oxidation of allyl iodide. Thus, the reactions depended only slightly on the structure of the MoO3.
Electrical Conductance of a Mixture of Sodium and Potassium Thiocyanates in Aqueous Medium at 25 °C
Authors: Gupta Ratan Lal , Ismail Kochi
Published: July 2006

Electrical conductance measurements of [xNaSCN+(1−x)KSCN]+RH2O system were made as functions of x and R at 25 °C. The mixed alkali effect was found to be negligible when R>10 and it increased sharply with increase in concentration in the range R≤10. The concentration dependence of molar conductance (Λ) has been described satisfactorily by the expression, Λ=ΛFHexp (Bm+Cm2) where ΛFH is the Falkenhagen–Leist–Kelbg equation for Λ, m is the molality and the parameters B and C are the empirical constants.
A Quantitative Scale of the Spectrochemical Series for the Mixed Ligand Complexes of d6 Metals
Authors: Shimura Yoichi
Published: July 2006

Quantitative scale of a new parameter d has been proposed for the spectrochemical series of ligands in the mixed ligand complexes of d6 metals, which enables us to predict the positions of low energy d–d absorption bands of a d6 complex. Introduction of a new reduction parameter α has improved the prediction of the d–d bands of mixed cyano complexes of cobalt(III), mixed halogeno complexes of rhodium(III), iridium(III), and platinum(IV), and also several mixed carbonyl complexes of low-valent d6 metals.
Sulfur Inversion in and Molecular Structure of meso-3,4-Diethyl-3,4-dimethyl-1-phenyl thiolanium Tetrafluoroborate
Authors: Oki Michinori , Yamada Yasuhisa , Murata Shigeru
Published: July 2006

Kinetics of sulfur inversion in the title compound was studied by the classical method to afford the following kinetic parameters for the process (1r,3R,4S)→(1s,3R,4S): ΔH\eweq 25.7±0.3 kcal mol−1, ΔS\eweq −2.2±0.8 cal mol−1 K−1. X-Ray crystallography of one isomer (1r,3R,4S) in which the methyl groups are cis to the phenyl group shows some abnormal bond lengths and conformations due to the steric congestion in the 3,4-region of the thiolane ring. The anomalies in the structure are pointed out by comparing the structure with those closely related and the correlation of them with the barrier height to inversion is discussed.
A New Method of α-Functionalization for Tertiary Amines by Nucleophilic Substitution of α-Siloxy Amines
Authors: Tokitoh Norihiro , Okazaki Renji
Published: July 2006

α-Siloxy amines, which were easily prepared by “silicon Polonovski reaction” of tertiary amine N-oxides with trialkylsilyl trifluoromethanesulfonate, were treated with various nucleophiles to give the corresponding α-functionalized tertiary amines in moderate to good yields. This new method has the advantage that it enables the α-substitution of amines not only by alkyl groups but also by alkenyl and aryl groups with sp2 carbon as a reaction center, since the introduction of such groups is difficult in electrophilic substitution of dipole-stabilized α-lithio amines. Besides the organometallics such as Grignard and organoaluminum reagents, trimethylsilyl cyanide and silyl enol ether could also be employed as nucleophiles in the presence of an appropriate Lewis acid.
New Series of Organic Metal. Radical Salts of Unsymmetrical Donors Containing Pyrazino Group
Authors: Kikuchi Koichi , Kamio Hiroyuki , Saito Kazuya , Yiannopoulos Stelios Y , Papavassiliou George C , Kobayashi Keiji , Ikemoto Isao
Published: July 2006

The I3, ClO4, and PF6 salts of unsymmetrical donors containing fused pyrazino groups (DMPDSDTF and DM(DMP)DSDTF) were prepared electrochemically and their electrical conductivities were measured. The I3 salt of DM(DMP)DSDTF exhibited a metallic behavior down to about 120 K. The radical salts of unsymmetrical donors showed much larger conductivities than those of the corresponding symmetrical donors containing pyrazino groups.
The Temperature Dependence of the Quenching Rate of the 307.6 nm Zinc Resonance Line by Some Alkane Hydrocarbons
Authors: Yamamoto Shunzo
Published: July 2006

The intensities of the 307.6 nm resonance line of zinc were measured as a function of the alkane pressure at various temperatures between 556 and 696 K, and the quenching rate was determined on the basis of the Stern–Volmer plots. Assuming that the quenching rate constant, kQ, of a certain alkane is equal to the sum of the quenching-rate constant, ki, for each C–H bond, the ratios of ks/kp and kt/kp (kp, ks, and kt are the quenching-rate constants for primary, secondary, and tertiary C–H bonds) were estimated from the ratios of the quenching rates of butane, isobutane, and neopentane. The differences in the activation energies for the quenching for primary, secondary, and tertiary C–H bonds were obtained from the temperature dependence of the ratios of ks/kp and kt/kp and were interpreted in terms of the modified bond-energy-bond-order (BEBO) method.
Synthetic, Spectroscopic and X-Ray Crystallographic Studies of Bivalent Metal Complexes with Amino Acids Having a Thiazolidine Ring. I. Properties of Bivalent Metal Complexes with (S)-4-Thiazolidinecarboxylic Acid and the Structure of Chloro((S)-4-thiazolidinecarboxylato)((S)-thiazolidinium-4-carboxylate)zinc(II)
Authors: Nagase Makoto , Yukawa Yasuhiko , Inomata Yoshie , Takeuchi Toshio
Published: July 2006

Complexes of five bivalent metals with (S)-4-thiazolidinecarboxylic acid((Remark: Graphics omitted.)) have been prepared by three methods and characterized by means of infrared absorption, reflection spectra, magnetic susceptibility, thermal analysis, powder X-ray patterns, and single crystal X-ray diffraction. Two types of complexes were found. The first type[A] included ML2·nH2O (M=Co(II), Ni(II), Cu(II), Zn(II), Cd(II); L=(S)-4-thiazolidinecarboxylate anion) and ZnClL(HL) was the second type[B]. In A-type complexes, the ligand coordinates to the metal with a nitrogen atom and an oxygen atom. From the results of single-crystal X-ray diffraction studies, the second type-B ZnClL(HL) was found to be orthorhombic, with the space group P212121; a=9.719(2), b=22.194(4), c=5.8537(5) Å, U=1262.6(4) Å3, Z=4, Dm=1.91 Mg m−3, Dx=1.93 Mg m−3, and μ(Mo K α)=25.3 cm−1. Block-diagonal least-squares refinements have led to a final R value of 0.045. The zinc atom is penta-coordinated, being ligated with one carboxylate oxygen atom of (S)thiazolidinium-4-carboxylate, which has a zwitter ion structure, two carboxylato oxygen atoms and one nitrogen atom of (S)-4-thiazolidinecarboxylate anion, and a chloride atom. The structure comprises onedimensional polymers by the carboxylate oxygen atom of this anion-type ligand. The plane extends in the direction of c-axis. In neither the A- nor the B-type complexes does the ligand coordinate to a metal with a sulfur atom.
Nematic Fumaric Ester Derivatives and Their Electro-Optical Properties
Authors: Shiraishi Kohei , Sugiyama Kazuo , Sakamoto Akihiko , Otsu Takayuki
Published: July 2006

Senven enantiotropically nematic fumaric ester derivatives, 1-[[(E)-3-alkoxycarbonyl)acryloyl]oxy]-4-(4-methoxyphenylazo)benzene (1), were prepared. The 1 compounds which have unbranched ester alkyl groups showed decreased phase-transition temperatures and narrowed nematic states with the increase in the length of the alkyl chain, while the 1 compounds with terminal branched alkyl groups decrease drastically in nematic thermal stability. From the electro-optical effect originating in the dynamical scattering at the nematic state of the 1 compounds with unbranched ester groups, it was found that both the threshold voltage (Ethres) of deformation and the electro-optial response time (τr) decrease with the decrease in the chain lengh of alkyl groups. In addition, τr is scarcely influenced over the wide temperature range above 12 eV·cm−1 of the electric field.
Electrochemical Studies of Poly(mercaptohydroquinone) and Poly(mercapto-p-benzoquinone) Films Prepared by Electropolymerization. II. Fixation of Heavy Metals and Their Electrochemical Properties
Authors: Arai Gorou , Ishii Takayuki , Yamamoto Sumi , Yasumori Iwao
Published: July 2006

Heavy metal ions, Ag+, Hg2+, Cd2+, Cu2+, Pb2+, Pd2+, Fe3+, and Pt4+, were each fixed on a conductive redox film of poly(mercapto-p-benzoquinone) or poly(mercaptohydroquinone) by mercaptide formation. Of these mercaptide-modified electrodes, the Pt(IV)-, Pd(II)-, and Ag(I)-modified electrodes possess some catalytic properties for electrochemical hydrogen evolution. These mercaptide-modified electrodes display a nearly Nernstian response to their respective heavy metal ions in aqueous solution and exhibit good durability when stored under appropriate conditions. Especially, the Hg(II)-modified electrode displays an excellent function as an Hg2+ ion sensor. The effect of miniaturization of substrates upon response ability was investigated by using two different-sized Pt wires (0.5 mm and 0.03 mm in diameter).
The Solvent Extraction of Palladium(II) from Aqueous Chloride Media with 7-Tridecanone Oxime
Authors: Inoue Katsutoshi , Baba Yoshinari , Yoshizuka Kazuharu , Oka Tetsuji
Published: July 2006

The extraction behavior of palladium(II) from the aqueous ammonium chloride solutions with the title extractant in toluene was investigated in terms of the equilibrium and the kinetics, while the aqueous solubility and the interfacial adsorption equilibrium of the extractant were estimated. The extraction rate of the 1:2 palladium(II)–extractant complex was explained by the interfacial reaction model, in which the ratedetermining steps were assumed to be the elementary reactions between the aquatrichloro- and tetrachloropalladate(II) in the aqueous phase and the extractant molecule adsorbed at the interface.
The Wetting of Alumina Substrate by Liquid Gold
Authors: Ushio Masumi , Sumiyoshi Yoshihiro
Published: July 2006

The wetting of an Al2O3 substrate by liquid gold was investigated by means of the sessile-drop method in an atmosphere of argon. An empirical relation was estabilished between the contact angle and the temperature or surface tension of the liquid drop by the use of the diameter and the height of the sessile drop. The contact angle was constant with time, but decreased linearly with an increase in temperature. The variation in the contact angle with temperature is correlated with the surface tension of the sessile drop. The surface tension of liquid gold was obtained as 933 dyn cm−1 at 1080 °C and 917 dyn cm−1 at 1100 °C and the temperature coefficient of the surface tension of liquid could be estimated to be −0.80 dyn cm−1 °C−1. The critical surface tension (γc) and the surface tension of liquid gold at 0 K of Al2O3 (γLV°) were 20 and 2015 dyn cm−1, respectively.
Preparation and Properties of Iron(II) Hydroxide–(Sodium Fluoride Tetrasilicic Mica) Intercalation Complexes
Authors: Ohtsuka Kunio , Suda Mitsuru , Ono Mikiya
Published: July 2006

Iron(II) hydroxide–(sodium fluoride tetrasilicic mica) intercalation complexes, which have a chloritelike structure, were prepared by titrating iron(II) sulfate solutions in the presence of mica with sodium hydroxide under oxygen-free conditions. The formation of iron(II) hydroxide sheets between the silicate layers was evaluated by chemical analysis, XRD, DTA-TGA, and surface-area measurement. The presence of water is essential for the oxidizing of these complexes to occur at room temperature by air, because the O2 attack on the surface of these iron(II) hydroxide sheets is hindered by the silicate layers. Fine highly dispersed iron metal particles (α-Fe) were formed on the external surface of the silicate by the H2 reduction of the complexes.
Enantioselectivity in the Biotransformation of Mono- and Bicyclic Monoterpenoids with the Cultured Cells of Nicotiana tabacum
Authors: Hamada Hiroki
Published: July 2006

The biotransformation of the enantiomeric pairs of p-menthane and bicyclo[2.2.1] and [3.1.1]heptane derivatives with the cultured cells of Nicotiana tabacum was investigated. It was found that (i) the cultured cells discriminate the enantiomers of p-menthan-2-ol and bicyclo[2.2.1]heptan-2-ol and bicyclo[3.1.1]heptan-3-ol derivatives, and enantioselectively convert these alcohols to the corresponding ketones, (ii) the cells reduce the carbonyl group of p-menthan-2-one derivatives to a high extent, but not that of p-menthan-3-ones, and (iii) the cells discriminate the enantiomers of bicyclo[3.1.1]hept-2-en-4-one (verbenone) and enantioselectively reduce the C–C double bond of the (1S,5S)-enantiomer.
A Facile Synthesis of 4H-Cyclopenta[def]phenanthrene
Authors: Minabe Masahiro , Yoshida Masaaki , Takayanagi Tokuei
Published: July 2006

A facile and cheap method for synthesis of 4H-cyclopenta[def]phenanthrene was achieved from fluorene as the starting material via di-t-butylfluorene.
Novel Ferroelectric Liquid Crystals Derived from Normal Alkyl Esters of (R)-3-Hydroxybutanoic Acid. The Correlation between Molecular Structure and Mesomorphic Properties
Authors: Nakauchi Jun , Sakashita Keiichi , Kageyama Yoshitaka , Hayashi Seiji , Mori Kenji
Published: July 2006

The following series of novel ferroelectric liquid crystals, derived from normal alkyl esters of (R)-3-hydroxybutanoic acid, have been synthesized, and several factors determining their mesomorphic properties have been investigated:

(Remark: Graphics omitted.)

The smectic polymorphism for these compounds with three aromatic rings is strongly affected by the position and kind of the linkage groups in the core. The effects of the lengths of the two terminal chains (m,n) and the linkage groups in the core on the thermal stability of the smectic A and chiral smectic C phases have been discussed from the structural points of view.
Photocatalytic Hydrogen Evolution from Aqueous Solutions of Sodium Sulfite Using Platinum-Loaded CdS1−xSex Mixed Crystal Powder
Authors: Uchihara Toshio , Abe Hirohisa , Matsumura Michio , Tsubomura Hiroshi
Published: July 2006

The CdS1−xSex mixed-crystal powder was prepared for the purpose to reduce the band gap of CdS and expand the effective wavelength region of the photocatalyst. Hydrogen evolution was observed from an aqueous solution of 1 M sodium sulfite by use of the mixed-crystal photocatalyst loaded with platinum under illumination at wavelengths longer than 520 nm, where neither the platinum-loaded CdS nor CdSe photocatalyst is active. However, when the mixed-crystal catalysts were illuminated at wavelengths longer than 390 nm or with an AM 1 solar simulator, the rate of the hydrogen evolution was lower than that of CdS. The energy levels of the electronic bands in the mixed-crystals have been clarified from the results of the electrochemical studies, and the fact that the mixed-crystal powder has lower photocatalytic activity than CdS powder has been ascribed to the downward shift of the conduction band edge. These findings are useful in designing photocatalysts for hydrogen production.
Stereoselective Isomerization Reaction of (Iminodiacetato)(ethylenediamine-N-acetato)cobalt(III), [Co(ida)(edma)], in a Basic Aqueous Solution
Authors: Kawaguchi Hiroshi , Miyamoto Hideko , Ama Tomoharu , Yasui Takaji
Published: July 2006

Isomerization reactions among four geometrical isomers (pink, violet, brown, and light-brown) of [Co(ida)(edma)] were studied in a basic aqueous solution. In a reaction of (−)554CD-pink, three isomers of (+)563CD-violet, (+)565CD-brown (with a low optical purity), and racemic light-brown formed simultaneously. The major products in reactions of (+)563CD-violet and (+)565CD-brown were (+)565CD-brown and (+)563CD-violet, respectively. Light-brown mainly isomerized to brown at a rapid rate. Moreover, it was found that (+)563CD-violet racemized at a considerable rate. These stereoselective reactions are discussed in connection with those for [Co(edma)2]+ and [Co(ida)2]−.
Cyclohepta[b][1,4]benzothiazines and Their Diazine Analogues. 2. Formation and Properties of Cyclohepta[b]quinoxalines
Authors: Shindo Kimio , Ishikawa Sumio , Nozoe Tetsuo
Published: July 2006

2-Chloro- or 2-methoxytropone reacts with o-phenylenediamine to give 2-(o-aminoanilino)tropone, which upon heating provides 6H-cyclohepta[b]quinoxaline (10a). Upon acidification, 10a reversibly gives a green cation, 9a. 10a is easily converted, especially under basic conditions, into the oxidative dimer 16a, which reproduces 9a by reduction with Zn in acetic acid. The isopropyl derivatives of these compounds are prepared by the same method from 5-isopropyl-2-methoxytropone. The 5-methyl (21a) and 5,11-dimethyl derivatives 23 are made by the reaction of 2-chloro- or 2-methoxytropone with N-methyl- and N,N′-dimethyl-o-phenylenediamines. However, the methylation of 21a with methyl fluorosulfate affords 5,11-dihydro-8,11-dimethyl-6H-cyclohepta[b]quinoxaline-5,6-sultone. H2O2 oxidation of 10a mainly gives 16a in addition to a small quantity of 6H-cyclohepta[b]quinoxalin-6-one. Compound 21a is stable under basic conditions, but 23 rearranges under alkaline conditions to give, among other unidentified products, N-methyl-N-[o-(methylamino)phenyl]benzamide and 5,10-dihydro-5,10-dimethyl-2-phenazinecarbaldehyde. Reactions of title compounds with alkali and hydrogen peroxide are compared with those of O- and S-analogues.
Preparation of New Nitrogen-Bridged Heterocycles. 19. Smooth Syntheses of Thieno[3,2-a]- and Thieno[2,3-b]indolizine Derivatives
Authors: Kakehi Akikazu , Ito Suketaka , Fujii Tuneo , Morimoto Yuichiro , Matsumoto Shin-ichi , Shiohara Morio
Published: July 2006

The reactions of 2-(ethoxycarbonylmethylthio)indolizines having an acyl and/or a cyano group at the 1- and 3-positions under several alkaline conditions were examined, and title compounds, thieno[3,2-a]- and thieno[2,3-b]indolizine derivatives were obtained in fairly good yields. The cyclization modes observed in these transformation reactions were in accord with those expected by the molecular orbital calculations using some model compounds and by the stereochemical consideration of starting indolizines. The alkylations of 3-hydroxythieno[3,2-a]- and 3-hydroxythieno[2,3-b]indolizines were also investigated and the corresponding O- and C-alkylated heterocycles were formed in good yields.
Continuous Electrochemiluminescence of [Ru(2,2′-bipyridine)3]2+ in Solution
Authors: Igarashi Ryuji , Nosaka Yoshio , Fujii Nobuyuki , Miyama Hajime
Published: July 2006

Electrochemiluminescence (ECL) of tris(2,2′-bipyridine)ruthenium(2+) ([Ru(bpy)3]2+) was observed in a propylene carbonate–dimethylacetamide–water mixed solvent by applying direct current (dc) voltage to a cell which consists of a sheet cathode of metals such as Al and Pt and a wire anode of Pt. The intensity of the dc ECL increased with the water concentration (up to 30 vol%) and the applied voltage. Besides water, oxygen was found to be necessary for observing the dc ECL. A plausible mechanism is the formation of [Ru(bpy)3]2+* from the reaction of [Ru(bpy)3]+ and HO2, those species are both produced at the cathode. This mechanism was supported by a separate experiment in which the chemiluminescence was observed by the reactions with a reducing agent.
Thermal Stability of Substituted Pyridine Adducts of Bis(acetylacetonato)oxovanadium(IV) in Solid State
Authors: Shibutani Yasuhiko , Shinra Koichiro
Published: July 2006

The kinetic of the elimination reaction of axial ligand B in [VO(acac)2B] complexes (Hacac=acetylacetone; B=pyridine, its derivatives, and ammonia) was studied in solid state by the Coats–Redfern method. The frequency factor and activation energy were determined, from which the activation free energy (ΔG\eweq) was calculated. The ΔG\eweq values varied with the nature of pyridine derivatives in the range of 99–109 kJ mol−1. The insight into ΔG\eweq values suggests that the kinetic stability of vanadium-substituted pyridine bond is influenced by both the basicity (pKa) and heat of sublimation (ΔH(sub)) of the axial ligand. Furthermore, the E′ values which appear to reflect coordination ability of base B were determined by reflectance spectra of the complexes. The E′ value was found to increase linearly with the increase in pKa and ΔH(sub) of the axial ligand.
Flow Chemiluminescent Determination of Catecholamines Based on Permanganate Oxidation
Authors: Ikkai Harumi , Nakagama Tatsuro , Yamada Masaaki , Hobo Toshiyuki
Published: July 2006

Luminous oxidation with acidic permanganate was found to be usable for chemiluminescent determination of catecholamines and other polyhydroxybenzenes at picomol levels. The sensitivity is high enough to determine catecholamines in urine. The present CL method is expected to be applicable to the post-column detection of these compounds in high-performance liquid chromatography.
Orientation of Isomeric Phthalic Acids on Alumina and Magnesia Surface Observed by Inelastic Electron Tunneling Spectroscopy
Authors: Higo Morihide , Mizutaru Sinichi , Kamata Satsuo
Published: July 2006

The vibrational spectra of phthalic, isophthalic, and terephthalic acid adsorbed onto alumina and magnesia surfaces from the gas phase have been measured by inelastic electron tunneling spectroscopy. The analysis of the tunneling spectra shows that phthalic and isophthalic acid react with the surface OH groups on Al2O3 and MgO to give the adsorbed dicarboxylate ions on both surfaces. Phthalic acid is adsorbed with its benzene ring perpendicular to the surfaces, while isophthalic acid is adsorbed parallel to the surfaces. However, terephthalic acid is adsorbed predominantly as the monocarboxylate ion almost perpendicular to the alumina surface, while it is adsorbed as the dicarboxylate ion parallel to the magnesia surface. These results suggest the different properties of the surface OH groups on Al2O3 and MgO. There are more than one type of OH group on the alumina surface and they interact with each other through hydrogen bonding. The magnesia surface has an isolated and a hydrogen-bonding OH group. The OH groups on MgO are more basic than those on Al2O3, and thus have higher reactivity. The different properties and basicity of the OH groups cause the different orientation and reactivity of the adsorbed terephthalic acid on the alumina and magnesia surfaces.
A Mechanistic Study on the Reaction of Iminothiadiazolines with Activated Acetylenes: Competitive Pathway through Hypervalent Sulfurane and Zwitterion
Authors: Yamamoto Yohsuke , Tsuchiya Tohru , Ochiumi Masahide , Arai Shin-ichi , Inamoto Naoki , Akiba Kin-ya
Published: July 2006

The reaction of 3-aryl-5-benzoyl-2-imino-2,3-dihydro-1,3,4-thiadiazoles (6) with dimethyl acetylenedicarboxylate (4b) gave the corresponding thiazole (8) and benzoyl cyanide through sulfurane (B) by 1,3-dipolar cycloaddition and cis- (9) and trans-vinyl (10) compounds through zwitterion (C) by simple addition. Two types of addition reactions competed each other and the ratio of the two [R=B/C] depended solely on the solvent polarity (ET). Dibenzoylacetylene behaved similarly. Several iminothiazolines and iminothiadiazolines reacted with activated acetylenes and the selectivity for the two types of addition reactions for each system was shown to be affected by quite subtle balance of electron-withdrawing ability of each heterocycle.
Syntheses of Fluoroalkyl and Fluoroaryl Titanates
Authors: Yoshino Norio , Tomita Junko , Hirai Hidefumi
Published: July 2006

Tetrakis(1H,1H-perfluoroethyl) titanate, Ti(OCH2CF3)4, tetrakis(1H,1H-perfluoropropyl) titanate, Ti(OCH2CF2CF3)4, tetrakis(2,2,2-trifluoro-1-methylethyl) titanate, Ti[OCH(CH3)CF3]4, tetrakis(2,2,2-trifluoro-1,1-dimethylethyl) titanate, Ti[OC(CH3)2CF3]4, tetrakis((1H,1H,3H-perfluoropropyl) titanate, Ti(OCH2CF2CF2H)4, tetrakis(1H,1H,5H-perfluoropentyl) titanate, Ti[OCH2(CF2CF2)2H]4, tetrakis(1H,1H,7H-perfluoroheptyl) titanate, Ti[OCH2(CF2CF2)3H]4, and tetrakis(1H,1H,9H-perfluorononyl) titanate, Ti[OCH2(CF2CF2)4H]4, were prepared by the reaction of titanium tetrachloride with fluoro-substituted alcohols in the presence of ammonia. Tetrakis(pentafluorophenyl) titanate, Ti(OC6F5)4 was synthesized by the ester interchange reaction of tetraisopropyl titanate with pentafluorophenyl acetate. These compounds were characterized on the basis of chemical analysis, IR, 1H NMR, 13C NMR and 19F NMR spectra. Tetrakis(2,2,2-trifluoro-1,1-dimethylethyl) titanate was the monomeric in nitrobenzene, but tetrakis(1H,1H-perfluoroethyl) titanate and tetrakis(1H,1H-perfluoropropyl) titanate were associated in the same solvent, in which the highest association numbers observed were 3.5 and 1.5, respectively. These titanates were very sensitive to moisture and easy to decompose to give titanium oxide and alcohol or phenol.