bluuebunny/crossref_metadata_2025_split huggingface dataset:
Spectrochemical Series for the Outersphere Coordination of Carboxylatocobaltate(III) Complexes with Solvent Molecules
Authors: Taura Toshiaki 
Published: July 2006

Abstract
The d–d transition spectra of K[Co(edta)]·2H2O, K[Co(mal)2en]·H2O, K[Co(ox)2en]·1.5H2O, K2[Co(ox)2gly]·3H2O, and K3[Co(ox)3]·3H2O (edta=ethylenediaminetetraacetate, mal=malonate, en=ethylenediamine, ox=oxalate, and gly=glycinate) were measured in a variety of solvents: H2O, HOCH2CH2OH, CH3OH, HCONH2, C2H5OH, i-C3H7OH, CHCl3, CH3NO2, CH2Cl2, (CH3)2SO, CH3CN, HCON(CH3)2, C6H5CN, C6H5NO2, CH3CON(CH3)2, (CH3)2CO, and [(CH3)2N]3PO. The 59Co NMR spectra of K[Co(edta)]·H2O and K3[Co(ox)3]·3H2O were also recorded at 25°C in these solvents. It was found that the peak positions (λmax) of the first and second d–d transition bands were greatly influenced by solvent molecules; the peak positions (λmax) of all the cobalt(III) complexes were linearly correlated to the electrophilic ability (Gutmann’s acceptor number) of the solvent and those of K[Co(edta)]·2H2O and K3[Co(ox)3]·3H2O were linearly correlated to the 59Co NMR chemical shifts in the corresponding solvents. This suggests that the d–d transition energy (ΔE) is influenced by solvent molecules as electron acceptors since 59Co NMR chemical shifts are theoretically correlated linearly to the peak positions in the first d–d transition (A1g–T1g). The 13C NMR measurements indicated that solvent molecules directly interact with the carboxyl groups of cobalt(III) complexes. Therefore, the influence of the solvent on the d–d transition energy of the carboxylatocobaltate(III) complex is due to the electron-withdrawing effect of solvent molecules on the carboxyl oxygens of the cobalt(III) complex. A spectrochemical series for the outersphere coordination of the cobalt(III) complex with solvent molecules is proposed.
Preparation and Characterization of Cobalt(III) Complexes Containing 4,7-Diphenyl-4,7-diphosphadecane-1,10-diamine and 4,8-Diphenyl-4,8-diphosphaundecane-1,11-diamine, NH2(CH2)3P(C6H5) (CH2)nP(C6H5)(CH2)3NH2 (n=2,3)
Authors: Kashiwabara Kazuo , Jung Minho , Fujita Junnosuke 
Published: July 2006

Abstract
Twelve new cobalt(III) complexes of the types, cisα-[Co(L)(rac(P)-323 or 333NPPN)p+ (L=2,4-pentanedionate (acac) and oxalate (ox) ions) (four complexes) and cisβ-[Co(L)(rac(P)- or meso(P)-323 or 333NPPN)p+ (eight complexes) were prepared and characterized by 1H NMR and absorption spectra, where rac(P)- and meso(P)-323NPPN denote rac(P)- and meso(P)-NH2(CH2)mP(C6H5)(CH2)mP(C6H5)(CH2)mNH2 with m=3 and n=2, and 333NPPN the ligand with m=3 and n=3. Reactivities of the complexes towards hydrochloric acid were examined and compared with those of the corresponding 222NPPN (m=2, n=2) and 232NPPN (m=2, n=3) complexes. All the cisα isomers yield the cisα-dichloro complexes, the 333NPPN and 222NPPN complexes being more reactive than the 232NPPN and 323NPPN complexes in which five- and six-membered chelate rings of NPPN are involved. For the cisα isomers, the acac complexes afford [Co(acac)(Cl)(mnmNPPNH+)]2+ except the rac(P)- and meso(P)-333NPPN complexes which give the trans-dichloro complexes, while all the ox complexes liberate the ox ion to yield the dichloro complex of the cisα, cisβ, or trans configuration. For both cisα-acac and -ox isomers, the 222NPPN and 232NPPN complexes are more reactive than those of 323NPPN and 333NPPN, and the meso(P)-complexes are more reactive than the rac(P)-complexes.
Unique Condensation Reactions of Tropones with Bis(benzoylthio)trithiafulvene Leading to 10aH-Cyclohepta[c]-1,3-dithiolo[e][1,2]dithiin-2-thione
Authors: Saito Katsuhiro , Ito Kazuaki , Kabuto Chizuko , Takahashi Kensuke 
Published: July 2006

Abstract
Reactions of tropone derivatives with 4,5-bis(benzoylthio)-1,3-dithiole-2-thione (2,3,6-trithiafulvene derivative) afforded 1,3,5-cycloheptatriene derivatives doubly substituted by trithiafulvene and S–S groups (10aH-cyclohepta[c]-1,3-dithiolo[e][1,2]dithiin-2-thione). The structure of the 1,3,5-cycloheptatriene derivative and its crystal structure were investigated by single crystal X-ray analysis to show the existence of a unique three-dimensional network of the molecules through S···S contacts.
The Cycloaddition of N,α-Diarylnitrones and Substituted p-Benzoquinones
Authors: Shiraishi Shinsaku , Inoue Yukihiko , Imamura Kiyoshi 
Published: July 2006

Abstract
N,α-Diarylnitrones reacted with 2,5- or 2,6-dialkyl-p-benzoquinones at their C=C bond regioselectively to give fused isoxazolidine cycloadducts. These cycloadducts were proved to undergo retrocycloaddition. p-Benzoquinones having electron-withdrawing substituents did not give any cycloadduct.
Synthesis of 5-Deoxy-5-phenylphosphino- and 5-Phenylphosphinyl-d-glucopyranoses
Authors: Hanaya Tadashi , Akamatsu Akihito , Kawamoto Heizan , Armour Margaret-Ann , Hogg Alan M , Yamamoto Hiroshi 
Published: July 2006

Abstract
(5R and 5S)-3-O-Acetyl-5-deoxy-1,2-O-isopropylidene-5-[(methoxy)phenylphosphinyl]-6-O-(tetrahydro-2-pyranyl)-α-d-xylo-hexofuranoses (7) were prepared from 3-O-acetyl-5,6-dideoxy-6-nitro-α-d-xylo-hex-5-enofuranose in 4 steps. Reduction of 7 with sodium dihydridobis(2-methoxyethoxy)aluminate followed by acid hydrolysis provided the title compounds, among which the 5-deoxy-5-phenylphosphino-d-glucoses are the first example of hexopyranose analogs having a phosphinidene group in place of hemiacetal ring-oxygen. These compounds were converted into 1,2,3,4,6-penta-O-acetates, whose structures were established by spectroscopy.
The Catalysis of Maghemite and Hematite on the Aldol and the Retro-Aldol Condensation of Acetone
Authors: Watanabe Haruo , Seto Jun’etsu 
Published: July 2006

Abstract
The catalytic activities of maghemite on the aldol condensation of acetone and on the retro-aldol condensation of diacetone alcohol are found to be higher than those of hematite. Further, the catalytic activity of maghemite on the formation of mesityl oxide is significantly higher than that of hematite. The active sites are considered to be surface hydroxyl groups which behave as a Brønsted base and acid points. Maghemite has more basic surface hydroxyl groups than does hematite, and far more acidic surface hydroxyl groups than does hematite they are sufficiently strong to make its average surface acidity greater than that of hematite. The basic surface hydroxyl groups of maghemite are speculated to be those which bond to the iron ions of the octahedral sites the acidic ones are those of the tetrahedral sites of the spinel lattice of the surface.
Synthesis, Structure, and Reactions of Stable Titanacyclopentanes
Authors: Mashima Kazushi , Sakai Nozomu , Takaya Hidemasa 
Published: July 2006

Abstract
Titanacyclic compounds of the formula Cp*2Ti(CH2CH2C(CH2CHR)CH2) (5a; R=H and 5b; R=C6H5, Cp*=pentamethylcyclopentadienyl), the first stable titanacyclopentanes, have been prepared by the reaction of bis(pentamethylcyclopentadienyl)titanium–ethylene complex (3) with methylenecyclopropanes (4), and their structures were determined based on both spectroscopic data and X-ray crystallography. Complex 5b crystallized in space group P21⁄a(Z=4) with cell constants, a=21.832(3), b=8.580(1), c=14.759(2) Å, β=96.81(1)°, U=2744.9(6) Å3 (4261 reflections, R=0.053). The reaction of 5 with carbon monoxide afforded spiro[2.4]heptan-5-ones in 98% yield. The thermal decomposition of 5 has been investigated, and possible mechanisms of the reactions have been proposed based on deuterium-labeled experiments. A novel formal reductive elimination of organic ligands giving 1-phenylspiro[2.4]hexane has been observed in the thermolysis of 5b. A structure–reactivity relationship has been discussed.
Mössbauer and Infrared Spectroscopic Studies of Some Alkyl- and Arylamine Coordinated Pentacyanoferrate(II) Complexes
Authors: Lanjewar Ratnakar Balkrishna , Garg Amar Nath 
Published: July 2006

Abstract
Mössbauer spectra of alkyl- and arylamine coordinated pentacyanoferrate(II) complexes, Na3[Fe(CN)5L]·xH2O where L=(CH3)3N, (CH3)2CHNH2, (CH3)2CHCH2NH2, (CH3)3C–NH2, C6H5NH2, C6H5NHCH3, C6H5N(CH3)2, C6H5NHC2H5, o-ClC6H4NH2, and p-ClC6H4NH2 have been studied. All compounds exhibit a well-resolved quadrupole doublet. An unusually high quadrupole splitting is observed for isobutylamine coordinated complex (ΔEQ=1.75 mm s−1). Other complexes show ΔEQ=0.67–0.86 mm s−1. A correlation of δ vs. ΔEQ suggests a positive sign of electric field gradient for isobutylamine coordinated complex and negative for all other complexes. Partial isomer shift (p.i.s.) and δ have been correlated with partial quadrupole splitting (p.q.s.). Also characteristic CN and Fe–N stretching frequencies have been correlated with δ to derive information on σ-donor and π-acceptor properties of the ligands.
Regioselective Hydrogenation Using Platinum-Support Zeolite Modified by CVD-Method
Authors: Kuno Hideyuki , Shibagaki Makoto , Takahashi Kyoko , Honda Ichiro , Matsushita Hajime 
Published: July 2006

Abstract
A platinum-support zeolite coupled with a silica layer was prepared by Chemical Vapor Deposition (CVD) of tetraethoxysilane, and was investigated in order to determine the catalytic characterization in an analysis of the surface. With this catalyst system, it was demonstrated that the terminal carbon–carbon double bond is preferentially hydrogenated in the case of several unsaturated hydrocarbons. Further, it was elucidated that a highly regioselective hydrogenation of compounds which possess plural double bonds was achieved over this catalyst system. As a result, a reaction model regarding this catalyst system has been put forward.
Aerobic Epoxidation of Olefinic Compounds Catalyzed by Tris(1,3-diketonato)iron(III)
Authors: Takai Toshihiro , Hata Eiichiro , Yamada Tohru , Mukaiyama Teruaki 
Published: July 2006

Abstract
Tris[1,3-bis(p-methoxyphenyl)-1,3-propanedionato]iron(III) (Fe(dmp)3) was found to be an excellent catalyst for oxygenation of a number of olefinic compounds including styrene analogues and olefinic alcohols into the corresponding epoxides in good to quantitative yields with combined use of molecular oxygen and an aldehyde at room temperature.
Mono-, Di-, and Tri-C-Deuteration of 1,5-Anhydro-d-glucitol
Authors: Funabashi Masuo , Hasegawa Toshimori 
Published: July 2006

Abstract
Deuterium was effectively introduced into the title sugar (1a) at C-1, C-3, C-5, and C-6 to afford 1,5-anhydro-d-[1-2H1], -[3-2H], -[5-2H], -[1-2H2], -[6-2H2], and -[5,6-2H3]glucitols respectively as primary targets for a basic study of the unknown metabolism of 1a, which had been suggested to be a candidate of metabolic indexes for insulin-dependent diabetes mellitus.
Synthesis and Crystal Structure of Seven-Coordinate (trans-1,2-Cyclohexanediamine-N,N,N′,N′-tetraacetato)aquavanadate(III)
Authors: Shimoi Mamoru , Miyamoto Shigeru , Ogino Hiroshi 
Published: July 2006

Abstract
Potassium, sodium, and ammonium salts of [V(cydta)(H2O)]− complexes were prepared, where cydta denotes trans-1,2-cyclohexanediamine-N,N,N′,N′,-tetraacetate. Crystal structure analysis of Na[V(cydta)(H2O)]·5H2O revealed that the vanadium(III) atom adopts a capped trigonal-prism structure, a cydta acting as a sexidentate ligand and an aqua ligand occupying the capping position.
Preparation and X-Ray Crystal Structure of trans-Dinitro(1,4,7,10-tetraazacycloheptadecane)cobalt(III) Tetrafluoroborate, trans-[Co(NO2)2(N410)]BF4
Authors: Tsuchimoto Masanobu , Kita Masakazu , Fujita Junnosuke 
Published: July 2006

Abstract
A new tetraaza-macrocyclic complex involving a ten-membered chelate ring, trans-[Co(NO2)2(N410)]BF4(N410=1,4,7,10-tetraazacycloheptadecane) was prepared and the structure was determined by the X-ray diffraction method. The ten-membered chelate ring takes a distorted boat–chairboat form with the N–Co–N bite angle of 105.4(1)°.
Crystal Structure of the Gold(III) Complex, Trichloro(dibenzyl sulfide)gold(III)
Authors: Takahashi Kazuhiro 
Published: July 2006

Abstract
The structure of the title complex has been determined. The crystal is orthorhombic, with the space group Pnma, Z=4, a=13.331 (2), b=16.130 (3), and c=7.6949 (9) A. The complex has a square-planar coordination geometry. The Au and the 3C11S donor atoms are located on a crystallographic mirror plane. The length of the Au–Cl bond trans to the Au–S bond is slightly longer than those of the other two Au–Cl bonds.
The Oxidation of p-Substituted Phenols Using a t-Butyl Hydroperoxide–Heteropolyacid System
Authors: Shimizu Masao , Orita Hideo , Hayakawa Takashi , Watanabe Yoshihito , Takehira Katsuomi 
Published: July 2006

Abstract
The oxidation of p-substituted phenols with t-BuOOH in the presence of heteropolyacids was carried out. 4-t-Butylperoxy-2,5-cyclohexadien-1-ones were obtained in good yields by the oxidation of 2,4,6-trialkylsubstituted phenols in this oxidation system.
Acid-Induced Dimerization Reactions of N-(Diphenylphosphinyl)-2-propenimines Leading to Pyridine Derivatives
Authors: Kakiuchi Hidetaka , Kobayashi Tomoshige , Kato Hiroshi 
Published: July 2006

Abstract
Treatment of N-(diphenylphosphinyl)-3-aryl-1-phenyl-2-propenimines with p-toluenesulfonic acid in heated xylene provided 4-aryl-2,6-diphenylpyridines and 4-aryl-3-arylmethyl-2,6-diphenylpyridines via an unprecedented dimerization reaction of the 2-propenimine.
Synthesis of Dimethyl 1,2-Cycloalkanedicarboxylates by Electrochemical Cyclization of Dimethyl α,α′-Dibromoalkanedioates Using a Copper Anode
Authors: Tokuda Masao , Hayashi Atsushi , Suginome Hiroshi 
Published: July 2006

Abstract
The electrochemical cyclization of dimethyl α,α′-dibromoalkanedioates by making use of a platinum cathode and a copper anode in the presence of sodium iodide gave three- to six-membered dimethyl 1,2-cycloalkanedicarboxylates in good yields.
Palladium Catalyzed Stereoselective Hydrodehalogenation of Alkenyl Halides with Tributyltin Hydride
Authors: Taniguchi Masahiko , Takeyama Yoshihiro , Fugami Keigo , Oshima Koichiro , Utimoto Kiitiro 
Published: July 2006

Abstract
The reduction of alkenyl halides with tributyltin hydride in the presence of a catalytic amount of tetrakis(triphenylphosphine)palladium has been studied. Alkenyl iodides reacted easily with tributyltin hydride at 25°C to give the corresponding hydrocarbons stereoselectively. However, the reaction of alkenyl bromides were sluggish at 25°C and needed heating at 75°C to complete.
Selective Halofluorination Reaction Mediated by Hexafluoropropene–Diethylamine Complex and N-Haloimides
Authors: Shimizu Makoto , Okamura Masaya , Fujisawa Tamotsu 
Published: July 2006

Abstract
Olefins were halofluorinated with hexafluoropropene–diethylamine and N-haloimides in a highly regio-and stereoselective manner.
Sedimentation Potential Measurements and Partial Molar Volumes of Univalent Ions in Water–Acetone Mixtures
Authors: Kawaizumi Fumio , Hirakawa Hiromitsu , Kubota Eiji , Nomura Hiroyasu 
Published: July 2006

Abstract
Sedimentation potentials and electrical conductivities were measured for NaCl, NaBr, sodium tetraphenylborate Na[BPh4], and tetraphenylphosphonium chloride [Ph4P]Cl in water–acetone systems (up to 50 wt% of acetone). Using the data obtained and the reported values of partial molar volumes V2∞, the ionic division of V2∞ was carried out. The values of V2∞ (Na+) evaluated for NaCl, NaBr, and Na[BPh4] were self-consistent and they work as references for ionic division of V2∞ (MX).
Extraction-Spectrophotometric Determination of Vanadium(V) with Pyrocatechol and N1-Hydroxy-N1,N2-diphenylbenzamidine
Authors: Agrawal Chandresh , Patel Khageshwar Singh , Mishra Rajendra Kumar 
Published: July 2006

Abstract
A sensitive procedure for spectrophotometric determination of V(V) with pyrocatechol and N1-hydroxy-N1,N2-diphenylbenzamidine (HDPBA) is described. The value of molar extinction coefficient (ε) of the colored complex in chloroform is 5.60×105 dm3 mol−1 cm−1 at λmax 410 nm. The optimization of analytical variables, effect of diverse ions and application of the method to environmental samples have been investigated.
Efficient Selective Reduction of Aromatic Nitro Compounds Affording Aromatic Amines under CO/H2O Conditions Catalyzed by Amine-Added Rhodium–Carbonyl Complexes
Authors: Nomura Kotohiro , Ishino Masaru , Hazama Motoo 
Published: July 2006

Abstract
Remarkably high catalytic activities for the reduction of aromatic nitro compounds affording aromatic amines using CO (1 atm) and water at room temperature were exhibited by using amine-added rhodium carbonyl complexes (Rh(CO)2(acac), Rh4(CO)12, and Rh6(CO)16) in 2-methoxyethanol or diglyme (diethylene glycol dimethyl ether) containing a 5 equiv NaOH aqueous solution. The reduction proceeded not only with high catalytic activities, but also with remarkably high nitro-group selectivities, as exhibited in the case of 1-nitroanthraquinone affording 1-aminoanthraquinone, without any other unsaturated groups, such as C=O, being reduced. The T. O. F. (turnovers/time) of 1776 mol-cat−1 h−1 (296 g-atom Rh−1 h−1) was attained for the reduction of p-nitroanisole yielding p-anisidine using Rh6(CO)16-1,8-bis(dimethylamino)-naphthalene catalyst.
Syntheses and Crystal Structures of Seven-Coordinate (Ethylenediamine-N,N,N′,N′-tetraacetato)aquavanadate(III) Complexes
Authors: Shimoi Mamoru , Saito Yoko , Ogino Hiroshi 
Published: July 2006

Abstract
K[V(edta)(H2O)]·2H2O (1a) was prepared by the reaction of VCl3 with K4 edta. The compound was converted to its sodium and ammonium salts by use of a cation exchange resin. Crystal structure analyses of Na[V(edta)(H2O)]·3H2O (1b) and NH4[V(edta)(H2O)]·2.5H2O (1c) revealed that in both compounds the vanadium atom adopts a capped trigonal-prismatic structures with a hexadentate ethylenediammetetraacetato ligand and an aqua ligand. Crystal data are as follows: 1b: Monoclinic, P21⁄a, a=17.831 (3), b=8.408 (1), c=11.595 (2) Å, β=109.39 (1)°, Z=4, R=0.045 for 6321 reflections; 1c: Monoclinic, Aa, a=8.552 (1), b=59.948 (6), c=7.226 (Å), β=114.95 (1)°, Z=8, R=0.050 for 6087 reflections.
Preparation and Characterization of N,N-Bridged and/or S,S-Bridged Sexidentate-N2,O2,S2 Cobalt(III) Complexes, Crystal Structure {(3S,8S)-2,2,9,9-Tetramethyl-1,10-dithia-4,7-diazacyclotetradecane-3,8-dicarboxylato}cobalt(III) Bromide
Authors: Okamoto Ken-ichi , Fushimi Norio , Konno Takumi , Hidaka Jinsai 
Published: July 2006

Abstract
Four kinds of cobalt(III) complexes with N,N-bridged, S,S-bridged, or N,N- and S,S-bridged (cyclo type) sexidentate-N2,O2,S2 ligand containing two d-penicillaminate moieties were newly synthesized. Of these complexes, the crystal structure of the title complex was determined by the X-ray diffraction method. The crystal was orthorhombic, space group P212121, a=16.935(5), b=23.506(7), c=13.057(6) Å, V=5198(3) Å3, Z=8, and the final R value was 0.0685. The ligand coordinates to the cobalt atom as the N,N- and S,S-bridged sexidentate-N2,O2,S2. The absolute configurations of the nitrogen and sulfur donor atoms are S(N),S(N) and R(S),R(S) respectively. The N,N-bridged five-membered ring is the gauche form with the δ conformation and the S,S-bridged seven-membered ring is the twist-chair form with the λ conformation. The other three complexes were characterized by their electronic absorption, 13C NMR, and circular dichroism (CD) spectra. The N,N- and/or S,S-bridged complexes showed the characteristic absorption and CD spectral behavior in the region of 16–24×103 cm−1.
Reactions of Leuco Bindschedler’s Green with Some p-Benzoquinones in Acetone
Authors: Osawa Yoshihiro , Nishimura Norio , Yamamoto Shunzo 
Published: July 2006

Abstract
The rate of reaction between Leuco Bindschedler’s Green (BGH) and some p-benzoquinone derivatives (Q’s) in acetone was followed spectrophotometrically by means of the stopped-flow technique. The reaction was found to proceed reversibly. The rate data and the activation parameters for the forward and backward reactions were estimated. The rates were susceptible to the oxidation–reduction potentials of the Q’s. The absorption spectra observed at low temperatures indicated that three kinds of intermediates were involved. Radicals formed during the reaction were detected by the ESR method. The results have been discussed in relation to those previously obtained for systems involving Leuco Crystal Violet (LCV) and Leuco Malachite Green (LMG).
Preparation of Optically Active [1-(Methoxycarbonyl)ethyl]cobaloximes Coordinated with Various Axial Ligands and Their Photoracemization. Remarkable Steric Effect of Axial Ligand on the Co–C Bond Homolysis
Authors: Ohgo Yoshiaki , Wada Hideki , Ohtera Chiyako , Ikarashi Makoto , Baba Shoe , Takeuchi Seiji 
Published: July 2006

Abstract
Optically active [1-(methoxycarbonyl)ethyl]cobaloximes coordinated with various axial bases were prepared and their photoracemization rates were measured in a solution state. It was found that although the electronic effect of the axial ligand was negligible on the rate of photochemical Co–C bond homolysis, the steric bulkines accelerated the rate remarkably. These results had a similar tendency to those observed in a previously reported reaction wtih 1-cyanoethyl cobaloximes, though the degree of rate enhancement due to the steric bulkiness of the axial ligand was extremely enlarged. The reason is also discussed.
Selective Formation of α-Cleavage Cycloadduct of Oxirane with Heterocumulene Promoted by High-Coordinated Trialkyltin Complexes
Authors: Yano Katsunori , Amishiro Nobuyoshi , Baba Akio , Matsuda Haruo 
Published: July 2006

Abstract
In the reaction of monosubstituted oxiranes and heterocumulenes, trialkyltin iodides coordinated by phosphine oxides effectively catalyzed the formation of heterocycles via cleavage at the substituted site in the oxirane ring, while other types of organotin complexes or noncomplexed organotin iodides promoted selective cleavage at the opposite site. A mechanistic investigation demonstrated that the coordination of phosphine oxide promotes the reverse reaction of the oxirane-ring cleavage leading to the predominant formation of α-cleavage cycloadducts.
Dye-Sensitized Oxygenation and Dimerization of 4-Methoxystyrene through Electron Transfer
Authors: Kojima Masanobu , Kuriyama Yasunao , Sakuragi Hirochika , Tokumaru Katsumi 
Published: July 2006

Abstract
Photoreactions of 4-methoxystyrene (1) sensitized with dyes such as Acriflavine, Rhodamine 6G, and Methylene Blue in methanol under oxygen afforded 4-methoxybenzaldehyde, its dimethyl acetal, and 2-methoxy-2-(4-methoxyphenyl)ethanol as oxidation products together with the corresponding dimers, cis- and trans-cyclobutanes in a ratio of cis/trans ca. 5/95. On the basis of quenching studies of fluorescence and T–T absorption of the dyes, the oxygenation and dimerization are proposed to proceed through an electron transfer from 1 to excited singlet dyes but not to involve generation of singlet oxygen.
Syntheses and Reactions of Metal Organics. XVI. Synthesis and Hydrolysis of Dimethoxysilanediyl Bis(polyfluoroalkanoate)
Authors: Yoshino Norio , Tominaga Shin-ichi , Hirai Hidefumi 
Published: July 2006

Abstract
Four new silicon compounds, dimethoxysilanediyl bis(5H-octafluoropentanoate), (CH3O)2Si[OCO(CF2)4H]2, dimethoxysilanediyl bis(7H-dodecafluoroheptanoate), (CH3O)2Si[OCO(CF2)6H]2, dimethoxysilanediyl bis(9H-hexadecafluorononanoate), (CH3O)2Si[OCO(CF2)8H]2, and dimethoxysilanediyl bis(pentadecafluorooctanoate), (CH3O)2Si[OCO(CF2)6CF3]2, were prepared by the reaction of dichlorodimethoxysilane with sodium salts of fluoro-substituted carboxylic acid. The 1H NMR, 13C NMR, and 19F NMR and IR spectral data of these silicon compounds were obtained. In the course of a study of the stability of the silicon compounds against hydrolysis by using 1H NMR spectral measurements, it was found that the ease of hydrolysis of the SiOCOR and the SiOCH3moieties was exactly same.