bluuebunny/crossref_metadata_2025 huggingface dataset:
The Crystal Structure of cis-Diammine(orotinato)platinum(II)
Authors: Solin Takaaki , Matsumoto Kazuko , Fuwa Keiichiro
Published: July 2006

From the reaction of cis-[Pt(NH3)2(H2O)2] with orotic acid, yellow needle crystals, green needle crystals, and dark-blue microcrystalline crystals were obtained. The results of elemental analyses, the IR absorption spectra, and X-ray Weissenberg photographs showed that the yellow and green needles are identical, whereas the dark-blue microcrystalline compound exhibits slight difference in the elemental analyses and IR spectra. Green needle crystals of cis-diammine(orotinato)platinum(II), cis-[Pt(NH3)2(C5H2N2O4)], were subjected to X-ray single crystal analysis. The crystals belong to the monoclinic system, with the space group P21/c, and the cell dimensions are a=7.468(5), b=7.537(3), c=15.618(9) Å, and β=107.90(7)°, with Z=4. The structure was solved by the heavyatom method and refined to the final R value of 0.0567 for 1918 non-zero reflections. The complex is almost planar, and the platinum atom is coordinated by the orotic acid at N1 and carboxylic oxygen, forming a fivemembered chelate ring. The structure of the pyrimidine ring of the orotic acid is compared with free and coordinated uracil and thymine. No definite explanation for the color difference was obtained.
The Complex Formation of the Copper(II) Ion with Ethylenediaminetetraacetic Acid and N-(2-Hydroxyethyl)ethylenediamine-N,N′,N′-triacetic Acid
Authors: Yamaguchi Shuichiro , Oyama Noboru , Ikeda Kazuo , Matsuda Hiroaki
Published: July 2006

The complex formation of the Cu(II) ion with ethylenediaminetetraacetic acid (EDTA) and N-(2-hydroxyethyl)ethylenediamine-N,N′,N′-triacetic acid (HEDTA) has been studied potentiometrically and polarographically over the wide pH range from 1 to 11 in aqueous solutions containing 1.0 mol dm−1 NaClO4 at 25.0 °C. Both the emf data obtained by potentiometric titrations and the pH-dependence of reversible half-wave potentials were explained in terms of the formation of the following complex species: for the Cu–EDTA complexes, CuL2− (logβ101=17.28±0.04), CuHL− (logβ111=20.15±0.04), CuH2L(logβ121=22.73±0.04), CuH3L+(logβ131=24.12±0.04), and CuH−1L3− (logβ1−11=6.83±0.05); for the Cu–HEDTA complexes, CuL− (logβ101=16.30±0.05), CuHL (logβ111=18.76±0.04), CuH2L+ (logβ121=19.85±0.04) and CuHL−1L2− (logβ1−11=6.35±0.05), where βpqr=[CupHqLr]/[Cu2+]p[H+]g[L]r, and where L denotes the unprotonated molecule of EDTA or HEDTA.
Dimerization of Tryptophan Derivatives in Trifluoroacetic Acid
Authors: Hashizume Kazunari , Shimonishi Yasutsugu
Published: July 2006

Side-products are formed when Ac–Trp–OMe, Ac–Gly–Trp–OMe, or Ac–Trp–Trp–OMe is stored in trifluoroacetic acid. Two products from each of Ac–Trp–OMe and Ac–Gly–Trp–OMe and one product from Ac–Trp–Trp–OMe are isolated by the column chromatography on silica gel and confirmed for homogeneity by the highperformance liquid chromatography. As confirmed by 1H-NMR and mass spectral analyses, they have dimerized structures through the α-carbon to α′-carbon binding of two indole rings. One of the two products from each of Ac–Trp–OMe and Ac–Gly–Trp–OMe is the trans-isomer(s) and the other the cis-isomer(s). Only a trans-isomer(s) is obtained from Ac–Trp–Trp–OMe.
The Crystal Structure of Dibromobis(iminodiacetamide)palladium(II)
Authors: Sekizaki Masao
Published: July 2006

The crystals are triclinic, P\bar1. R is 0.047 for 1617 independent non-zero reflections. The complex has a centrosymmetric square-planar coordination, with two imino nitrogen and two bromine atoms in trans positions.
Abnormal LiAlH4 Reduction of 4,4-Diphenyl-3-cyano-2-methyl-2-pyrrolin-5-one
Authors: Akabori Sadatoshi , Takahashi Kazue , Ohtomi Michiko , Sakamoto Yohko
Published: July 2006

The reduction of 4,4-diphenyl-3-cyano-2-methyl-2-pyrrolin-5-one with lithium aluminum hydride yields three unexpected reduction products, together with the usual product.
Vacuum UV Photoelectron Intensity of Gaseous Compounds. II. Experimental Processes of Determination of Differential and Partial Photoionization Cross Sections
Authors: Achiba Yohji , Yamazaki Tomoko , Kimura Katsumi
Published: July 2006

Experimental processes recently developed to determine differential and partial photoionization cross sections of molecules are described in detail, based on photoelectron intensity measurements using a gaseous binary mixture of a sample with a standard gas. The quantities obtained here in these processes are 1) relative photoelectron peak heights, 2) normalized photoelectron spectra, 3) relative photoelectron band areas, and 4) differential and partial photoionization cross sections. Corrections are made for electron collecting efficiency. In connection with the photoelectron intensity determination, we propose here a method of obtaining the mole ratio of the components of a binary mixture entered into the ionization chamber of a photoelectron spectrometer. Satisfactory results on partial photoionization cross sections have been obtained for several testing samples.
Molecular Structures of the Reduced 1,2,4-Triazine Derivative and Its Reaction Product with Electron-deficient Acetylene
Authors: Ayato Hiroshi , Tanaka Isao , Yamane Takashi , Ashida Tamaichi , Sasaki Tadashi , Minamoto Katsumaro , Harada Katsuhiko
Published: July 2006

The molecular structures of 3-methylthio-2-rnethyl-5,6-diphenyl-2,5-dihydro-1,2,4-triazine (1) and its reaction product with dimethyl acetylenedicarboxylate, 5,6-bis(methoxycarbonyl)-2-methyl-1-methylthio-4,8-diphenyl-2,3,7-triazabicyclo[3.3.0]octa-3,6-diene (2), were determined by the X-ray method. The former belongs to the triclinic system P\bar1, with Z=2, a=10.776(2), b=10.203(2), c=8.556(1) Å, α=105.44(2), β=104.94(2), and γ=60.31(2)°; the latter belongs to the orthorhombic system Pca21 with Z=4, a=18.166(2), b=7.444(2), and c=16.080(2) Å. Both structures were solved by the direct method. The final R-factors are 0.075 for 1 and 0.048 for 2. In Compound 1 the dihydrotriazine ring is in the boat form, while in Compound 2 both of the cis-fused five-membered rings are in the envelope form.
Metal Complexes of Amino Acids. XIII. The Relationships between the 13C Chemical Shifts and Ligand Field in the trans(O)-[Co(O)2(N)4] Type Complexes
Authors: Ama Tomoharu , Kawaguchi Hiroshi , Yasui Takaji
Published: July 2006

The relationship between the ligand field of the carboxyl groups and the chemical shift of carboxyl carbon or α-carbon has been investigated on the basis of the absorption and 13C-NMR spectral data of the trans(O)-[Co-(OCO-R)2(en)2]Xn type complexes (OCO-R denotes amino acid or fatty acid coordinating unidentately with the carboxyl group to cobalt (III)). The linear correlations were observed between the \barνmax (1Eg component of the first absorption band) and the chemical shifts of carboxyl- and α-carbons.
Synthesis of (+)-Hinokiol, (+)-Hinokione, (+)-Salviol, and (+)-2-Oxoferruginol
Authors: Matsumoto Takashi , Usui Shuji , Kawashima Hiroyuki , Mitsuki Masanori
Published: July 2006

Reduction of abieta-5,8,11,13-tetraen-3-one with lithium aluminium hydride afforded the corresponding alcohol, which was submitted to catalytic hydrogenation to yield abieta-8,11,13-trien-3β-ol (7) together with its 5βH-isomer. Acetylation of 7, followed by the Friedel-Crafts acylation, afforded 3β-acetoxy-12-acetylabieta-8,11,13-triene. This compound was converted into 3β,12-diacetoxyabieta-8,11,13-triene (11) by the Baeyer-Villiger oxidation. Treatment of 11 with lithium aluminium hydride yielded hinokiol, which was oxidized to hinokione. Subsequently, hinokiol was methylated and the resulting 12-methyl ether was dehydrated to afford 12-methoxyabieta-2,8,11,13-tetraene. The tetraene was then submitted to hydroboration-oxidation to give 12-methoxyabieta-8,11,13-trien-2α-ol (15) which, on demethylation with ethanethiol and anhydrous aluminium chloride, afforded salviol. Oxidation of 15 with pyridinium chlorochromate, followed by demethylation, gave 2-oxoferruginol.
Reaction between Azibenzil and Diarylmethanimine
Authors: Mehrotra Kailash Nath , Prasad Girija
Published: July 2006

The thermal reaction of azibenzil with diarylmethanimine (1) leads to N-(diarylmethylene)diphenylacetamide (2) which from methanol or ethanol yields N-(α-alkoxydiarylmethyl)diphenylacetamide (4). The reduction of 2 with sodium borohydride gives N-(diarylmethyl)diphenylacetamide. The photochemical reaction of azibenzil and 1 results in the formation of cyano ethers besides the amido ethers 4. A mechanism of formation of products is discussed.
Synthesis and Activity of Antitumor Agents, Methyl [N′-(2-Chloroethyl)-N′-nitrosoureido]deoxygentiobiosides
Authors: Fukuda Yoshimasa , Suami Tetsuo
Published: July 2006

Chlorozotocin and GANU are nitrosoureido derivatives of d-glucose, exhibiting remarkable antitumor activities against leukemia L1210 in mice. We wish to report a synthesis of the derivatives of gentiobioside.
The Activities of Sodium Salts of 1-Amino-4-alkylaminoanthraquinone-2-sulfonic Acid in Aqueous Solutions
Authors: Mitsuishi Masaru , Yamaguchi Yuzoh
Published: July 2006

The mean activity coefficients of sodium salts of 1-amino-4-alkylaminoanthraquinone-2-sulfonic acid (alk= Me(MAS), Et, n-Pr, or n-Bu (n-BAS)) in aqueous solutions ranging in concentration from 10−3 to 10−2 mol kg−1 have been determined by means of isopiestic measurements at 50 and 60 °C respectively. It has been found that the mean activity coefficients of these dyes are much smaller than unity, the coefficients of MAS being the largest, and those of n-BAS, the smallest. The coefficients have been found to decrease with an increase in the dye concentration. An examination of the results obtained by Miliceivic treatment suggests that the MAS exists as dimer or trimers, and the other dyes, as tetramers, at 60 °C.
The Crystal Structure of [N-(t-Pentyloxycarbonyl)-l-prolyl]-l-alanylglycine
Authors: Yamada Yasuyuki , Tanaka Isao , Ashida Tamaichi
Published: July 2006

The crystal structure of the title compound was determined by the X-ray method. The space group is P21,with a=18.741(3), b=12.602(1), c=9.553(1) Å, β=118.46(2)°, and Z=4. The structure was determined successfully by the vector-space-search method, using a dimer structure of Boc–Pro–Val–Gly–OH as a rigid group. The final R value was 0.075 for 2025 non-zero reflections. Two independent molecules related by a pseudo twofold axis are linked by β-sheet-type hydrogen bonds. This kind of dimerization commonly occurs in all the Boc–Pro–X–Gly–OH peptides except Boc–Pro–Leu–Gly–OH. The packing similarity of these peptides is discussed.
The Extraction of the Vanadium(V)-Pyrocatechol Violet Complex with Tridodecylethylammonium Bromide
Authors: Shijo Yoshio , Shimizu Tokuo , Sakai Kaoru
Published: July 2006

Vanadium(V) can be quantitatively extracted from an aqueous solution into carbon tetrachloride as the ion-association system formed between its Pyrocatechol Violet complex anion and tridodecylethylammonium salt. The optimum pH range for the extraction is around 5. The ternary complex has an absorption maximum at 570 nm in the organic layer. The distribution ratio and the molar absorptivity are 1.78×102 and 4.0×104 mol−1 cm−1 respectively. Omitting the other adducts which may be combined with vanadium, the composition of the ternary complex is estimated to be V(PV)2(R3R′N)2. The extraction constant is given by logKex=12.58. The interference of foreign ions is discussed, too.
An X-Ray Photoelectron Spectroscopic Study of Several Hydroxy Azo Metal Complexes
Authors: Yoshida Tooru
Published: July 2006

The X-ray photoelectron spectra of the copper(II) and nickel(II) complexes of five o-hydroxy azo compounds were measured. The N(1s) electron spectra of the complexes of 1-phenylazo- and 1-(1-naphthylazo)-2-naphthols showed the presence of only one kind of nitrogen atom, suggesting an equalization in the electron densities on the two nitrogen atoms of an azo group. Such equalization was observed also in the complexes of 1-(8-quinolylazo)-2-naphthol. The N(1s) spectra of the complexes of 1-(2-pyridylazo)- and 1-(2-thiazolylazo)-2-naphthols, on the other hand, showed the presence of three kinds of nitrogen atoms, suggesting the non-equalization of the two nitrogen atoms of an azo group. These results were explained mainly on the basis of the mode of ligand coordination and the resonance structure of the sodium salt of the ligand. Furthermore, the relation between the structures of the complexes and the O(1s) chemical shifts was discussed.
Reaction of Acetals with Grignard Reagents
Authors: Ishikawa Hiroshi , Mukaiyama Teruaki , Ikeda Shigeru
Published: July 2006

The reaction of dialkyl acetals derived from α,β-unsaturated aldehydes with Grignard reagents using TiCl4in THF afforded the cross coupling products, allyl ethers, in high yields. The TiCl4-promoted reaction of alkyl 2,4-dichlorophenyl acetals, synthesized from 3,4-dihydro-2H-pyran or ethyl vinyl ether and 2,4-dichlorophenol, with Grignard reagents in THF at low temperature afforded the corresponding unsymmetrical ethers in high yields. When alkyl 2,4-dichlorophenyl acetals, synthesized from aromatic aldehyde or vinyl ethers and 2,4-dichlorophenol, were treated with Grignard reagents in benzene or toluene at room temperature in the absence of TiCl4, the cross coupling reaction took place and the corresponding ethers were isolated in good yields.
Cyclic Carbene–Palladium(II) Complexes Derived from the Reactions of Isocyanide–Palladium(II) Complexes with Nitrilimines and Nitrilylides
Authors: Fuchita Yoshio , Hidaka Kazuhisa , Morinaga Shigeki , Hiraki Katsuma
Published: July 2006

cis-[PdCl2(PPh2R1)(CN–C6H4–CH3-p)] (R1=Ph or Et) reacts with nitrilimines or nitrilylides, derived from the reactions of either N-phenylarenecarbohydrazonoyl chlorides or N-(p-nitrobenzyl)arenecarboximidoyl chlorides with triethylamine, to afford novel cyclic carbene–palladium(II) complexes, viz. 1,2,4-triazol-5(4H)-ylideneor 2-imidazolin-5-ylidenepalladium(II) ones, respectively. Halogen exchange reactions of the carbene complexes with lithium bromide or sodium iodide give the corresponding dibromo- or diiodocarbene complexes, respectively. trans-[PdI2(PPh2-C6H4-CH3-p)(CN-C6H4–NO2-p)] also reacts with the nitrilimine or the nitrilylide to produce cyclic carbene–palladium(II) complexes. All the complexes prepared in this study are characterized by elemental analysis, IR and 1H-NMR.
Measurement and Analysis of the ν4 Band of Fluoroform and Its Molecular Constants
Authors: Sofue Susumu , Kawaguchi Kentarou , Hirota Eizi , Fujiyama Tsunetake
Published: July 2006

The ν4 fundamental of fluoroform has been measured with a tunable diode-laser source spectrometer. The following molecular constants were determined: ν0=1377.8458 cm−1, B4=0.344788 cm−1, C4=0.189134 cm−1 (Cζ)4=0.18619 cm−1, D4J=3.78×10−7 cm−1, D4JK=−5.73×10−7 cm−1, D4K=2.94×10−7 cm−1, η4J=1.44×10−6 cm−1, and η4K=−8.2×10−7 cm−1. Using the molecular constants of the 2ν3, the Coriolis x-y interaction constant between the ν4 fundamental and 2ν3, |ζ334|, was estimated to be 0.065.
X-Ray Photoelectron Spectrum of Cr2O5
Authors: Tsutsumi Takayoshi , Ikemoto Isao , Namikawa Tatsuru , Kuroda Haruo
Published: July 2006

The X-ray photoelectron spectrum of the powder of Cr2O5 was measured and compared with those of the related chromium compounds. It is concluded that Cr2O5 is a mixed-valence compound having Cr3+ and Cr6+ ions, possibly with the ratio of 1 : 2.
Effect of Ionic Strength on the Metachromatic Behavior of Dye–Polymer Systems
Authors: Yamaoka Kiwamu , Takatsuki Mineo
Published: July 2006

The effect of added sodium chloride on the metachromatic interaction between cationic dyes (Crystal Violet, Trypaflavine, and 9-aminoacridinium chloride) and sodium polyphosphate and poly(ethylenesulfonate) was studied in aqueous solutions by measuring the visible absorption spectra and by determining the bound-dye spectra and the equilibrium constants with the principal component analysis.
Vibrational Spectra and Normal Coordinate Calculations for Trimethylsilane
Authors: Imai Yoshika , Aida Koyo
Published: July 2006

Vibrational spectra of trimethylsilane-d0, -d1, -d9 and -d10 have been obtained. Assignments for all the fundamentals have been made assuming C3V molecular symmetry. Normal coordinate calculations have been carried out to confirm the assignments.
Structural Study of Optical Resolution. XI. The Crystal Structures of (+)589-Tris(biguanide)cobalt(III) Chloride d-Tartrate Trihydrate and Racemic Tris(biguanide)cobalt(III) Trichloride
Authors: Tada Toshiji , Kushi Yoshihiko , Yoneda Hayami
Published: July 2006

The crystal structures of the more-soluble diastereomeric salt, (+)589-[Co(Hbg)3]Cl(d-tart)·3H2O (1), and the racemic chloride salt, [Co(Hbg)3]Cl3 (2), have been determined by X-ray analysis (R=0.033, 2788 reflections for 1 and R=0.056, 2785 reflections for 2), where Hbg=C2H7N5, d-tart=C4H4O62−. The more-soluble salt 1 is orthorhombic, with the space group P212121  Z=4, a=15.654(2), b=13.758(2), and c=11.010(1) Å. The racemic salt 2 is monoclinic, with the space group C2/c, Z=8, a=19.441(9), b=14.901(7), c=15.911(6) Å, and β=127.63(2)°. In 1, the complex cations and the Cl− ions are arranged alternately to form an infinite spiral chain, {Δ-[Co(Hbg)3]Cl}∞. Each d-tartrate is hydrogen-bonded to a twofold-screw-axis-related neighbor (–OH···OOC– 2.792 Å) to form an infinite chain, (d-tart)∞. In 2 two kinds of similar infinite spiral chains, {Δ-[Co(Hbg)3]Cl}∞ and {Λ-[Co(Hbg)3]Cl}∞, which are mirror images of each other are found. The structures of these two salts 1 and 2 are compared with those of the less-soluble diastereomeric chloride d-tartrate and the optically active chloride in both of which a similar infinite chain has been found, and the mechanism of chiral discrimination via the diastereomer formation is discussed.
Phosphatosulfates. Metal-ion Effects on the Acid-catalyzed Hydrolysis of Phenyl Phosphatosulfate in an Acetonitrile–Water Mixed Solvent
Authors: Eiki Toshio , Asai Yoshio , Tagaki Waichiro
Published: July 2006

The rates of the acid-catalyzed hydrolysis of phenyl phosphatosulfate (PPS) have been found to be highly dependent on the water content in the mixed solvent of acetonitrile–water. A remarkable rate acceleration was observed with a rate maximum near the 1 : 1 ratio of PPS and metal ion, and with a solvent with a low water content. Under such conditions, the site of the cleavage of the P–O–S linkage was observed to be predominantly the S–O bond.
Photoinduced Intramolecular Substitution. II. Absence of meta-Favoring Effect in Nucleophilic Photosubstitution of Nitroveratrole Derivatives
Authors: Mutai Kiyoshi , Yokoyama Kenji , Kanno Sei-ichiro , Kobayashi Keiji
Published: July 2006

Possible occurrence of the photo-Smiles rearrangement accompanying meta-favoring nucleophilic aromatic substitution was examined in a homologous series of 1-(2-methoxy-4-nitrophenoxy)-ω-anilinoalkanes. The structure of reaction products, the reaction kinetics, and absorption spectra of intermediates showed no appreciable alteration of reaction pathway by the introduction of 2-methoxyl group. The photoreaction was exclusively a para-directing nucleophilic substitution.
A New Preparative Method of 2,2-Dimethyl-2H-chromenes
Authors: Kawase Yoshiyuki , Yamaguchi Seiji , Horita Hisanori , Takeno Junko , Kameyama Hideaki
Published: July 2006

2,2-Dimethyl-2H-chromene was prepared from salicylaldehyde and ethyl 3-methyl-2-butenoate (or ethyl α-bromoisobutyrate) in one step. This new method of preparing 2,2-dimethyl-2H-chromene was studied and applied to some 2,2-dimethyl-2H-chromene derivatives.
Synthesis of 3β-Hydroxytaxodione and Coleons S and T
Authors: Matsumoto Takashi , Kawashima Hiroyuki , Iyo Koji
Published: July 2006

Hinokiol diacetate was converted into 3β-acetoxyabieta-8,11,13-triene-6β,12-diol via 3β,12-diacetoxyabieta-8,11,13-trien-7-one and 3β,12-diacetoxyabieta-6,8,11,13-tetraene. Oxidation of the 6β,12-diol with benzoyl peroxide produced 3β-acetoxy-12-benzoyloxyabieta-8,11,13-triene-6β,11-diol, which was converted into 3β,11,12-triacetoxyabieta-8,11,13-trien-6-one by lithium aluminium hydride reduction, acetylation, and Jones oxidation. Acidic hydrolysis of the triacetoxy ketone, followed by column chromatography on silica gel, afforded 3β-hydroxytaxodione. Oxidation of the 6β,11-diol with m-chloroperbenzoic acid afforded 3β-acetoxy-12-benzoyloxy-6β-hydroxyabieta-8,12-diene-11,14-dione. This was further converted into 3β,11,14-triacetoxy-12-benzoyloxyabieta-8,11,13-triene-6,7-dione by a series of reactions: Jones oxidation, reduction with zinc powder and dilute hydrochloric acid, acetylation, and Jones oxidation. Alkaline hydrolysis of the 6,7-dioxo compound afforded coleon T, which was isomerized to coleon S by refluxing with concentrated hydrochloric acid in methanol.
Partition Coefficients of Chlorobenzenes in Heptane–Water and Heptane–Acetonitrile Systems
Authors: Suzuki Nobuo , Yoshida Toshinobu , Watarai Hitoshi
Published: July 2006

Partition coefficients (KD) of benzene and 11 chloro derivatives of benzene were determined at 25 °C in two liquid-liquid partition systems: heptane/water and heptane/acetonitrile. Increase of KD with increase of the numbers of Cl atoms in the solute is discussed in terms of surface and cohesive energies. The small difference in KD of the isomers whose Cl atom numbers are 2, 3, or 4 was correlated with a difference in the dipole moment of the solute.
The Crystal and Molecular Structure of Strontium Bis(thiocyanate)-Hexaethylene Glycol (1/1)
Authors: Yamaguchi Iwao , Miki Kunio , Yasuoka Noritake , Kasai Nobutami
Published: July 2006

The molecular structure of strontium bis(thiocyanate)-hexaethylene glycol(1/1) has been determined from single crystal X-ray diffraction data(3121 observed reflections): triclinic, space group P\bar1, a=12.086(4), b=8.732(2), c=10.628(2) Å, α=80.88(2), β=101.99(3), γ=100.55(2)°, Dm=1.48, Dc=1.48 g cm−3 for Z=2. The central Sr ion is coordinated by seven O atoms from the hexaethylene glycol moiety and two N atoms from the SCN groups; the Sr–O distances range from 2.603(5) to 2.750(5), while the Sr–N distances are 2.628(8) and 2.634(8) Å. The hexaethylne glycol moiety assumes a GT2\barGT2GT2\barGT2GTG2 conformation.
The Quenching of Excited Zinc(3PJ) Atoms by Alkane Hydrocarbons
Authors: Yamamoto Shunzo , Nishimura Norio
Published: July 2006

The intensities of the 307.6 nm resonance line of zinc were measured at different pressures of alkane hydrocarbons, and the quenching-rate constants were determined on the basis of the Stern-Volmer plots. A remarkable dependence of the quenching cross-section on the C–H bond strength was observed, and the relative decrease in the quenching cross-section with an increase in the C–H bond strength was interpreted in terms of the semiempirical bond-energy-bond-order(BEBO) method.
The Effects of Multivalent Anions on the Aluminium Ion-assisted Aquation of the Pentaamminefluorocobalt(III) Complex
Authors: Iida Masayasu , Ando Mieko , Yamatera Hideo
Published: July 2006

The presence of multivalent anions, such as sulfate, oxalate, and malonate ions, accelerated the aluminium ion-assisted aquation of CoF(NH3)52+ and gave the anionopentaamminecobalt(III), along with the aqua complex. The competition reaction for the sulfate ion showed a saturation of the product percentage (33% CoSO4(NH3)5+) at nearly [SO42−]total=0.1 mol dm−3, while the saturation of the reaction rate was observed at a higher sulfate concentration. This difference can be explained by a scheme in which the reaction proceeds through two intermediates, CoF(NH3)52+·SO42−·Al3+ and SO42−·CoF(NH3)52+·SO42−·Al3+. The reaction for the oxalate and malonate ions gave extremely large yields (more than 90%) of CoA(NH3)5+ (A2−=oxalate ion or malonate ion) when [A2−]total/[Al3+]total>2, and the reaction rates showed a maximum at approximately [A2−]total/[Al3+]total=2. These specific effects can be attributed both to the strong affinities of the dicarboxylate ions for the aluminium ion and to the residual capacity of the aluminium-bonded dicarboxylate ions for coordinating with cobalt(III).
Reactivity of Fe2O3 and Fe2O3–Al2O3 Mixture for Reduction of SO2 with CO
Authors: Ishii Tadao , Furuichi Ryusaburo , Shikano Koji
Published: July 2006

Catalytic reactivities of α-Fe2O3 powder (−200 mesh) and a α-Fe2O3–γ-Al2O3 powder mixture prepared by mechanical mixing, which were preheated at 360–700 °C, were studied for the reduction of SO2 with CO by means of both a reaction gas-chromatographic technique using CO, SO2, and 2CO–SO2 pulses and the powder X-ray analysis. The reactivity of Fe2O3 decreases with increasing preheating temperature, which is explained on the basis of redox reactions between Fe2O3 and nascent (Fe3O4): 6Fe2O3+2CO→4(Fe3O4)+2CO2 and 4(Fe3O4)+SO2→6Fe2O3+1/2S2. It is considered that the reactivity of Fe2O3 is attributable to the activity of (Fe3O4). The lifetime of active (Fe3O4) is within about 1 min, and the activity and lifetime of (Fe3O4) is increased by interfacial reaction between Fe2O3 and Al2O3 at 700 °C. The activity maximum in the Fe2O3–Al2O3 system preheated at 700 °C is attained at 70–75 wt% Fe2O3.
Preparation and Spectroscopic Studies of Stereoisomers of the Tris[(S)-1-phenyl-1,3-propanediamine]cobalt(III) Complex
Authors: Kojima Masaaki , Fujita Junnosuke
Published: July 2006

Three, fac-Δ, fac-Λ, and mer-Δ, of four possible diastereomers of the [Co(S-phtn)3]3+ complex (S-phtn=(S)-1-phenyl-1,3-propanediamine) were obtained by two methods, a reaction between trans-[CoCl2(S-phtn)2]+ and S-phtn in DMSO (dimethyl sulfoxide), and oxidation of a DMSO solution containing Co(II) ions and S-phtn with air in the presence of active charcoal. Neither method yielded the mer-Λ isomer. The absorption and circular dichroism spectra of the isomers were recorded in water in the absence and presence of Na2SO4, and in DMSO. The shifts of the first absorption bands caused by changing solvents and the changes of circular dichroism spectra caused by the addition of sulfate ions seem to be related with the conformational instability of the flexible six-membered chelate ring in the complexes. The tetraammine complex of S-phtn was also prepared.
The Formation Process of Cobalt Sulfide from Tricobalt Tetraoxide Using Sulfur Dioxide as a Sulfidizing Agent
Authors: Matsuzaki Ryoko , Yajima Akimasa , Eguchi Motonori , Saeki Yuzo
Published: July 2006

The products obtained by heating a mixture of Co3O4 and carbon in a SO2 stream were CoO and CoSO4 at 400–600 °C, Co1−xS and CoO at 650–700 °C, and Co1−xS (Co0.90S) at 750–800 °C. Sulfur was obtained outside the heating zone throughout the temperature range. The possible reactions during the above process were also examined. Further, thermodynamical consideration was made of the formation of Co1−xS. The formation process of Co1−xS (Co0.90S) from Co3O4 can be represented as follows: The reaction of carbon with SO2 occurs at first to form sulfur. Above ca. 400 °C, the reaction of Co3O4 with SO2 occurs to form CoO and CoSO4. Above ca. 500 °C, the reductions of Co3O4 with carbon and with sulfur also occur to form CoO. Above ca. 600 °C, the reduction of Co3O4 with carbon occurs to form CoO. Above ca. 650 °C, Co1−xS is formed by the reaction of CoO with sulfur, both of which had been formed by the above reactions.
Photo-induced Ring-opening Reactions of 1-(2-Naphthoyl)aziridine in Various Solvents
Authors: Nishimoto Sei-ichi , Izukawa Tsukuru , Kagiya Tsutomu
Published: July 2006

Photoreactions of 1-(2-naphthoyl)aziridine (NAz) have been investigated in various solvents under the deaerated conditions at room temperature. The photo-irradiation of NAz in halogenated hydrocarbons afforded halogen substituted secondary amides such as N-(2-chloroethyl)-2-naphthamide (CENA) or N-(2-bromoethyl)-2-naphthamide (BENA), a ring-expanded isomer of 2-(2-naphthyl)-2-oxazoline (NOz) and the NAz oligomer containing a chlorine atom. Secondary amides such as N-(2-methoxyethyl)-2-naphthamide (MENA) and N-ethyl-2-naphthamide (ENA) were obtained together with NAz oligomer in methanol and 2-propanol, respectively. The formation of N-(2-phenoxyethyl)-2-naphthamide (PENA), phenyl-2-naphthoate (PN) and NAz oligomer was observed in phenol (72 vol%)-acetonitrile mixture.
Quantitative Structure-activity Relations in Pyrazolylpyrimidine Derivatives for Their Analgesic Activities
Authors: Miyashita Yoshikatsu , Seki Tomoko , Yotsui Yasuhiko , Yamazaki Ken-ichi , Sano Mitsuji , Abe Hidetsugu , Sasaki Shin-ichi
Published: July 2006

Statistically significant correlations have been demonstrated between analgesic activities of a series of pyrazolylpyrimidine derivatives and molecular properties. The structural parameters are partition coefficients, molar refractivities, an indicator variable, and MO indices obtained from the CNDO/2 method. The influence of the torsional angle between the pyrazole and pyrimidine rings on the electronic state was examined. The correlations indicate that transport and partition processes and electronic factors play a major part in determining the analgesic activity. In particular, of electronic parameters MO indices on the pyrazole ring are significant. These structure-activity relationships can be used to estimate the analgesic activities with some degree of confidence.
Total Synthesis of (±)-Pisiferic Acid, Methyl (±)-Pisiferate, and (±)-Pisiferol
Authors: Matsumoto Takashi , Usui Shuji
Published: July 2006

Acid catalyzed cyclization of 4-(3-isopropyl-4-methoxyphenethyl)-3,5,5-trimethyl-2-cyclohexen-1-one afforded 12-methoxyabieta-8,11,13-trien-2-one and its cis-isomer. Both compounds were further converted into 12-methoxyabieta-8,11,13-trien-2β-ol, which was treated with lead tetraacetate in the presence of iodine to yield 2β,20-epoxy-12-methoxyabieta-8,11,13-triene. Ether cleavage of the 2β,20-epoxy compound with acetyl p-toluenesulfonate, followed by catalytic hydrogenation, afforded 20-acetoxy-12-methoxyabieta-8,11,13-triene (23). This was then converted into methyl 12-methoxyabieta-8,11,13-trien-20-oate (27) via methyl 12-methoxy-7-oxoabieta-8,11,13-trien-20-oate. Demethylation of 27 with AlBr3–EtSH gave pisiferic acid, but with AlCl3–EtSH 27 was partially demethylated to give methyl pisiferate. The acetate 23 was also converted into pisiferol by demethylation and reduction.
A New Method for the Determination of Equilibrium Constant and Molar Extinction Coefficient of 1 : 1 Type Complex
Authors: Seal Bejoy Kumar , Sil Harideb , Banerjee Manas , Mukherjee Dulal Chandra
Published: July 2006

Job’s method of continuous variation has been reinvestigated with respect to the formation of 1 : 1 type complex from the view point of (i) geometrical significance of the Job curve, (ii) developing a method for determining the equilibrium constant and molar extinction coefficient of the complex. A mathematical analysis of the method of continuous variation as applied to the formation of strictly 1 : 1 type complex shows that the Job curve is a hyperbola obeying the equation

\frac(d–β)2a2−\frac(CM°⁄λ–1⁄2)2b2=1

where d is the corrected optical density, CM° is the initial concentration of the metal ion in solution, λ is a constant equal to the sum of the concentrations of the metal and the ligand in solution, β is the ordinate of the local origin of the hyperbola referred to the conventional framework of the Job curve, a and b represent respectively the semi-major and semi-minor axes of the hyperbola. The equation has been recast into the form x=A3d2+A2d+A1, where x=(CM°/λ–1⁄2)2 and A3, A2, and A1 are the appropriate coefficients. A parabolic fit of this equation between x and d by the least square deviation method using the computer B-6800 system enables one to find the coefficients A3, A2, and A1 from which K and ε are evaluated. This equation has been tested with literature data on a variety of 1 : 1 type metal complexes whose formation constants and extinction coefficients as calculated by the present method agree closely with those determined by other methods. The promising features of the equation have been discussed.
A New Synthesis of Aldehydes and Aldehydes-d from Grignard Reagents
Authors: Yamashita Masakazu , Miyoshi Kanako , Nakazono Yutaka , Suemitsu Rikisaku
Published: July 2006

Aldehydes were prepared from Grignard reagents in high yields using pentacarbonyliron as the carbonylating agent. This reaction was also found to be applicable to the synthesis of aldehydes-d.
13C and 19F Chemical Shifts Induced by C–H···Base Hydrogen Bonding. Particular Polarizations of C–Halogen and C=C Bonds
Authors: Ueji Shinichi , Nakamura Michiko , Kitadani Masayuki , Sera Akira
Published: July 2006

The 13C and 19F chemical shifts induced by C–H···Base hydrogen bonding were measured for dichlorofluoromethane, chloroform, pentachloroethane, and trichloroethylene. These chemical shifts were shown to be linear using the β scale of hydrogen-bond acceptor basicities proposed by Kamlet and Taft. The analysis of the linear solvation energy relationships reveals that the particular polarizations of the C–halogen and C=C bonds play an important role in the C–H···Base hydrogen-bond formation.
Synthesis of Cyclic Silyl Diazo Compounds
Authors: Sekiguchi Akira , Ando Wataru
Published: July 2006

Cyclic silyl diazo compounds, 1-diazo-2,2-diphenyl-4-bromo-1,2-dihydro-2-silanaphthalene, 6-diazo-1,1-dimethyl-2,3,4,5-tetraphenylsilacyclohexa-2,4-diene, and 10-diazo-9,9-dimethyl-9,10-dihydro-9-silaanthracene, were prepared and their spectroscopic properties were determined.
Absolute Configurations of α-Substituted Glycidates. (−)-(R)-Ethyl 2-Methyl-1-oxaspiro[2.5]octane-2-carboxylate and (−)-(R)-Ethyl 2,3-Dimethyl-2,3-epoxybutanoate
Authors: Sugita Toshio , Nishio Nobuyuki , Ichikawa Katsuhiko
Published: July 2006

The absolute configurations of the title compounds were determined by chemical correlation and by asymmetric syntheses.
Studies on the Polymerization of Acrolein Oxime. XVI. Structure of 8-Hydroxy-1,4,5,7-tetramethyl-6,8-diazabicyclo[3.2.1]oct-6-ene 6-Oxide
Authors: Ota Tadatoshi , Masuda Seizo , Tanaka Hitoshi , Kido Masaru
Published: July 2006

The thermal oligomerization of 3-methyl-3-buten-2-one oxime leads to crystalline nitrone derivatives, 8-hydroxy-1,4,5,7-tetramethyl-6,8-diazabicyclo[3.2.1]oct-6-ene 6-oxide. Its crystal structure has been determined by X-ray diffraction. The space group is P21/n with a=9.459(3), b=10.335(3), c=11.352(4) Å, β=105.50(2)°, and Z=4.
Electron Spin Resonance of X-Irradiated Single Crystals of Dicyclohexyldiazene 1,2-Dioxide
Authors: Fujii Yoshihisa , Kashiwagi Michio , Nakada Hideki , Kurita Yukio
Published: July 2006

ESR studies of X-irradiated single crystals of dicyclohexyldiazene 1,2-dioxide, (C6H12NO)2, revealed the generation of the stably trapped radicals C6H11N(O)N′H″(O′)C6H11. The principal elements of the g value were found to be 2.0030, 2.0060, and 2.0086. The principal elements of the hyperfine coupling constants were found to be 3.88, 1.53, and 1.38 mT for N, and 1.53, 1.41, and 1.14 mT for H″. The direction cosines of these principal elements, when compared with those of the bonds in the parent molecule, indicate that the radical is formed by addition of a hydrogen atom to the N=N′ double bond without causing a large change in the molecular framework. The spin densities for this radical were calculated to be 0.041 and 0.47 in the 2s and 2p orbitals of the atom N, respectively.
Solvent Dependence of the Circular Dichroism Spectra of Some cis-Dianionobis(ethylenediamine)cobalt(III) Complexes
Authors: Sakaguchi Ushio , Nakazawa Hiroshi , Sakai Kazuhisa , Yoneda Hayami
Published: July 2006

The circular dichroism spectra of some cis-bis(ethylenediamine)cobalt(III) complexes have been measured in several solvents. Among these complexes, the diisothiocyanato complex was found to exhibit a marked solvent dependence; the dominant circular dichroism band in the lowest energy spin-allowed transition region changed its sign upon going from, e.g., water, dimethyl sulfoxide, methanol, or acetone to pyridine or its analogues. Coupled with the proton NMR spectra and a similar solvent dependence of the circular dichroism spectra of nitroisothiocyanatobis(ethylenediamine)cobalt(III) and diisothiocyanatobis(ethylenediamine)chromium(III) complexes, we ascribed the origin of the sign inversion of the diisothiocyanato complex to the stereoselective hydrogen bonding of cis N–HB with pyridine-like molecules, where cis N–HB is the hydrogen bonded to the nitrogen atom cis to NCS− and directed off the molecular twofold axis.
Mechanisms of Enzymatic S-Oxygenation of Thioanisole Derivatives and O-Demethylation of Anisole Derivatives Promoted by Both Microsomes and a Reconstituted System with Purified Cytochrome P-450
Authors: Watanabe Yoshihito , Oae Shigeru , Iyanagi Takashi
Published: July 2006

Oxygenations of thioanisole derivatives have been shown to be promoted with phenobarbital induced rabbit liver microsomes. In order to understand the mechanistic details of the oxygenations, a kinetic study on the S-oxygenation promoted by a reconstituted system with purified cytochrome P-450 has been carried out. Log(Vmax) were correlated with the one electron oxidation potentials of the sulfides (Ep). The oxygenation is considered to proceed via one electron transfer from the sulfides to the iron-bound “oxenoid” intermediate of the enzyme. A similar O-demethylation of anisoles has been investigated. In the oxidative O-demethylation of p-methoxy-d3-anisole with rabbit liver microsomes, an intramolecular kinetic isotope effect of 3.4 was observed. Meanwhile, a large isotope effect of 5.1 was observed in the competitive O-demethylation of p-dimethoxybenzene and p-di(methoxy-d3) benzene. In order to clarify the oxidation pathway of O-demethylation with the enzymatic system of cytochrome P-450, the rates of the O-demethylation of p-substituted anisoles have been measured. Unlike the enzymatic oxygenation of sulfides, there was no correlation between the rates of O-demethylation reaction and one electron oxidation potentials of anisoles. These observations suggest that the O-demethylation of anisoles proceeds via the initial hydrogen abstraction with the iron-bound “oxenoid” intermediate of the cytochrome P-450.
The Thermodynamics of Ion Exchange of Singly Charged Cobalt(III) Complex with Sodium Ions on Cation Exchange Resin
Authors: Kurotaki Katsumi , Kawamura Shoichi
Published: July 2006

Thermodynamic values of the ion exchange of [CoIIIL4B2]+ (L=NH3, ethylenediamine/2 (=en/2), or dimethylglyoximato (1−) anion/2 (=dmgH/2); B=NO2−, NCS−, CO32−/2, NH3, or C2H5NH2) with Na+ on Dowex AG 50W-X2 resin were determined at 25 °C by measurements of selectivity coefficient and heat of exchange. Heats and entropies are negative for the uptake of [Co(NH3)4(NO2)2]+ and [Co(en)2B2]+, while they are positive for the uptake of [Co(dmgH)2(C2H5NH2)2]+.
Effect of Polymorphic Transition on Molecular Diffusion in Some Molecular Complexes, as Evidenced by Exchange Reaction Rate and by Electrical Resistivity
Authors: Inabe Tamotsu , Matsunaga Yoshio
Published: July 2006

Marked increases in electron donor and acceptor-exchange reaction rates and also large differences in the temperature dependence of the electrical resistivity of polycrystalline compactions between the first and the second heating processes indicate the enhanced molecular diffusion near and above the polymorphic transition temperatures of some molecular complexes.
Liquid Crystal Formation in Binary Systems. VI. Smectic Liquid Crystals Induced in N-[4-(Diethylamino)benzylidene]-4-ethoxyaniline-N-(4-Nitrobenzylidene)-4-ethoxy-aniline and Related Systems
Authors: Araya Kotaro , Homura Noriko , Matsunaga Yoshio
Published: July 2006

The replacement of the dimethylamino group in the combinations of the 4-dimethylamino-4-alkoxy and 4-nitro-4-alkoxy derivatives of N-benzylideneaniline by a diethylamino group favors the induction of smectic phases in their mixtures.
Zero-field Energy Levels in Near-doubly-degenerate Triplet States
Authors: Higuchi Jiro
Published: July 2006

The zero-field energy levels in neardoubly-degenerate triplet states are discussed on molecules which are distorted so as to lose their trigonal symmetry axes. As an example, the second excited triplet states of a deformed benzene molecule are calculated from the electron spin-spin interactions.
Comparison of Association Constants Derived from CD and UV Measurements. The Case of Λ-Tris(ethylenediamine)cobalt(III) and Δ-Tris((1R, 2R)-1,2-cyclohexanediamine)cobalt(III) with Thiosulfate Ion
Authors: Yoneda Hayami , Miyoshi Katsuhiko , Matsukawa Hitoshi
Published: July 2006

The association constant KA determined by CD measurement is much smaller than that by UV measurement for the Λ-[Co(en)3]3+–S2O32− system in water, whereas the two kinds of measurements yield almost the same KA values for the Δ-[Co(l-chxn)3]3+–S2O32− system. These results are discussed in relation to possible interaction modes involved.
Dynamic Structure of Pyrimidine-polyribonucleotides in Solution. 1H NMR Studies
Authors: Yamada-Nosaka Atsuko , Nosaka Yoshio , Akasaka Kazuyuki , Hatano Hiroyuki
Published: July 2006

Temperature dependent conformations and molecular motions of pyrimidine polyribonucleotides, poly(C) and poly(U), have been studied in 2H2O solutions (pH 5.8±0.3, 5–72 °C by measuring 1H NMR intensities, chemical shifts, coupling constants, and spin-lattice relaxation times. Below 50 °C, poly(C) exists as a slowly exchanging mixture of double-stranded and single-stranded forms of which only the single-stranded form is observable by 1H NMR. In this temperature range, the single-stranded poly(C) shows a strong base-stacking with dominated C3′-endo anti conformation, whereas above 50 °C it takes partly C2′-endo conformation with destabilization of the helical structure. Poly(U) exists as single strand within the whole temperature range studied, and the bases are nearly unstacked with 58% of C2′-endo conformer. Poly(U) is more flexible than poly(C), which was characterized with rotational correlation times in the order of 10−9–10−10 s.
Studies on Molecular Motion in Lyotropic Mesophases of Hexaethylene Glycol Dodecyl Ether–D2O System by 13C Nuclear Magnetic Resonance
Authors: Mita Shigeru , Kondo Shoichi , Takeda Masatami
Published: July 2006

The 13C spin-lattice relaxation time(T1) and the resonance line width corresponding to T2* were measured for each of the carbons in hexaethylene glycol dodecyl ether–water(D2O) system, which exists as two distinct lyotropic mesophases(neat and middle phase). The line width is very narrow in the isotropic state, such as in organic solvents and in a lower concentration aqueous solution, whereas in a mesophase and in a higher concentration aqueous solution, the line width of the alkyl chain was broadened. Here the line widths for glycol carbons were about an order of magnitude smaller than for an alkyl chain, demonstrating the difference of molecular motion. The chemical shifts of the alkyl chain in the middle phase were different from those in the isotropic state; this difference was clearly shown in the spectrum of the middle/isotropic coexistent phase. 13C-T1 was not sensitive enough to differentiate between the isotropic and the lyotropic phase at room temperature. It was found that T1 did not equal T2* for any of the methylene carbons, the difference being most marked for the terminal methyl carbon in the alkyl chain. The orientational order in the phases had an influence on the T2* values.
Circular Dichroism of N-Acetyl-l-amino Acid Methylamides with Aromatic Side Groups
Authors: Matsuura Hiroatsu , Hasegawa Kodo , Miyazawa Tatsuo
Published: July 2006

The circular dichroism (CD) and its temperature dependence were studied on N-acetyl-l-phenylalanine methylamide, N-acetyl-l-tyrosine methylamide, and N-acetyl-l-tryptophan methylamide, as model molecules of aromatic amino acid residues in proteins. The CD spectra indicated that the increase in temperature and the decrease in solvent polarity give a similar effect on the amide π*←n transition. The CD behavior of the tryptophan derivative was different from that of the phenylalanine and tyrosine derivatives, suggesting that the bulkier indolyl side group interacts with the peptide backbone in a different way. The noticeable temperature dependence of the CD intensities in the 250–300 nm region observed for the phenylalanine and tryptophan derivatives suggested the coexistence of various conformers at higher temperatures.
A Conductance Study of Alkali Metal Ion-Benzo-15-crown-5 Complexes in Propylene Carbonate
Authors: Takeda Yasuyuki
Published: July 2006

The formation constants (KML+) for 1:1 complexes of benzo-15-crown-5 (B15C5) with alkali metal ions at 25 °C, and the enthalpy (ΔH) and entropy changes (ΔS) of the K+–B15C5 complex in propylene carbonate (PC) have been determined conductometrically. The KML+ series of B15C5 for the alkali metal ions are given in the order Na+>Li+>K+>Rb+>Cs+. The selectivity tendency of B15C5 for the alkali metal ions is consistent with the size-fit concept, however, B15C5 shows poor selectivity. Both the ΔH and ΔS values for the complexation reaction of B15C5 with K+ are negative. In the cases of Na+, K+, Rb+, and Cs+, the size of the moving entity in PC is larger for the B15C5 complex than for the corresponding alkali metal ion, while, in the case of Li+, that is completely the reverse.
Distinct Activation Energies for Temporal and Spatial Oscillations in the Belousov-Zhabotinskii Reaction
Authors: Yoshikawa Kenichi
Published: July 2006

Temperature dependence of the frequencies in temporal oscillations and of the moving-wave velocities of concentric waves in spatial oscillation in the Belousov-Zhabotinskii reaction was studied in detail using the same starting concentrations of the reactants. When cerium ions were used as catalyst, the activation energies were found to be 60–65 kJ/mol for the temporal oscillation and 46±4 kJ/mol for the spatial oscillation. The difference in the activation energies was well explained by the theoretical prediction based on kinetic-diffusion coupling. When [Fe(phen)32+] or [Fe(bpy)32+] was used as catalyst, the apparent activation energy in the temporal oscillation depends markedly on the concentration of the catalyst used.
Optical Studies on the Lowest Triplet State of Chromone
Authors: Yamada Yasuko , Yamauchi Seigo , Hirota Noboru
Published: July 2006

The lowest excited triplet state of chromone was investigated via high resolution phosphorescence spectra, phosphorescence excitation spectra and triplet lifetimes in the neat crystal, in the single crystals of durene and benzoic acid at liquid helium temperature. Including the cases in other solvents such as 3-methylpentane, methylcyclohexane and ethanol, the lowest triplet state was assigned to be ππ* type contrary to the previous assignment. The triplet sublevel properties including the sublevel spectra were obtained in the benzoic acid host. Ty is radiative at the 0-0 band. Tz is radiative at the non to tally symmetric bands and is active in nonradiative transitions. These properties are discussed and compared with those of other carbonyl compounds. A brief comment on the photochemical reactions are given.
The Structure and Properties of (η-Cyclopentadienyl)(O-methyl dithiocarbonato)(triphenylphosphine)nickel(II)
Authors: Shimoi Mamoru , Ouchi Akira , Sato Shoichi , Saito Yoshihiko
Published: July 2006

The title complex was synthesized, and the structure was determined by means of the X-ray diffraction technique. The crystal is triclinic; space group P\bar1, a=9.944(1), b=14.336(2), c=9.759(1) Å, α=107.00(1), β=117.35(1), γ=76.55(1)°, Z=2, Dx=1.40, Dm=1.36(3) g cm−3, μ(Mo Kα)=1.08 mm−1. The O-methyl dithiocarbonato ion acts as a unidentate ligand, and it is coordinated with the metal through one sulfur atom. The coordination number of the metal is 3 if the cyclopentadienyl is regarded as a unidentate ligand. A series of [(η-cyclopentadienyl)(O-alkyl dithiocarbonato)(trialkyl- or triarylphosphine)nickel(II)], [Ni(C5H5)(S2COR)(PR′3)], where R=CH3, C2H5, CH3(CH2)2, (CH3)2CH, or CH3(CH2)3; R′=C6H5, C6H5CH2, or CH3(CH2)3, were also obtained. The dissociation of the phosphine ligand of the complexes in solution was studied spectrophotometrically, and it was found that the more electron-donative the alkyl group of the O-alkyl dithiocarbonato ligand is, the weaker the phosphorus-nickel bond is.