bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and Reactions of Titanoxycarbene–Metal Carbonyl Complexes
Authors: Mashima Kazushi , Jyodoi Kouki , Ohyoshi Akira , Takaya Hidemasa
Published: July 2006

A family of titanoxycarbene–metal carbonyl complexes of formula Cp*2TiOC(=MLn)CH2CH2 (3), where Cp*=η5-C5Me5 and MLn=Cr(CO)5, Mo(CO)5, W(CO)5, Mn2(CO)9, and Re2(CO)9, has been prepared by the treatment of titanocene-ethylene complex 1 with metal carbonyls of group 6 and 7. Complex 3b crystallizes in space group P2⁄a (Z=8) with cell constants a=30.401(1), b=9.251(1), c=27.561(5) Å, β=105.73(1)°, and V=7460(2) Å3 (data taken at −40 °C, 6715 reflections, R=0.069). Two independent molecules of 3b in crystal make an enantiomorphic pair. A notable feature of the structure is the long distance of Ti–O bond coupled with the short distance of C(2)–O bond, which is characterized by a large contribution of zwitterionic canonical form 7. Thermal decomposition of 3 affords ethylene and the corresponding metal carbonyls, indicating that the C(carbenic)–C(3) bond fission occurred selectively, which is rather unusual for conventional Fischer-type carbene complexes. Complexes 3 react rapidly with atmospheric pressure of carbon monoxide below −30°C to produce cyclic acyltitanium complexes 12. The reverse reactions occur even below −30°C upon replacement of carbon monoxide by argon. Complex 3b also reacts with t-butyl isocyanide with a cleavage of the Ti–O bond to give 1 : 2 adduct 17, whose molecular structure has been elucidated by X-ray crystallography [P21⁄n with cell constants a=14.964(2), b=26.207(4), c=14.719(3) Å, β=100.30(1)°, and V=5679(2) Å3 (measured at −120°C, 5311 reflections, R=0.068)], revealing that it has a novel zwitterionic structure possessing (η2-imidoyl)titanium cation and anionic acyldirhenium carbonyl moieties linked by an ethylene bridge. The controlled experiments show that complex 16 in which acyl ligand is trans to the Re–Re bond is the precursor of complex 17. Complex 18, a tungsten analogue of 17, has also been prepared. Reactions of 3b and 3e with acetylenes are also described.
Stability Constants of Imidazole– and Alkylimidazole–Copper(II) Complexes
Authors: Imai Hiromu , Tamura Hiroshi
Published: July 2006

The stability constants of imidazole (HIm)– and alkylimidazoles–copper(II) acetate complexes were calculated from the potentiometric titration data with the aid of the SUPERQUAD computer program. The stability constants of ionic species of [CuALr]+ type (A : CH3COO, L : HIm a, 1-CH3·Im b, 2-CH3·HIm c, 4-CH3·HIm d, 2-C2H5·HIm e, 2-(CH3)2CH·HIm f, r=1, 2, 3, and 4) detected from the complexes were ascertained to be decreased in the order of b(1-substituted)≥d(4-substituted)>c(2-substituted) relating to the position of methyl group bonded to the imidazole ring, and c(2-CH3)>e(2-C2H5)>f(2-(CH3)2CH) relating to the kinds of alkyl group substituted on 2-position, respectively. The stability of these ionic species was discussed from the neutralization effect of the charge and the steric effect of alkyl group or acetate ion. The stability constants of the hydroxo species of [CuL2(OH)2] type indicated the extremely small values, and its order did not indicate a similar tendency with those of ionic species of [CuALr]+ types. The distribution of these complex species was investigated as a function of pH.
Archaebacterial Lipids: Surface Pressure–Surface Area Isotherms of 1,1′-(1,32-Dotriacontanediyl)bis[2-[(3RS,7R,11R)-3,7,11,15-tetramethylhexadecyl]-sn-glycero-3-phosphochoIine]
Authors: Yamauchi Kiyoshi , Yamada Katsu , Kinoshita Masayoshi , Kamikawa Tadao
Published: July 2006

1,1′-(1,32-Dotriacontanediyl)bis[2-[(3RS,1R,11R)-3,7,11,15-tetramethylhexadecyl]-sn-glycero-3-phosphocholine] (the tetramethylhexadecyl group=phytanyl) was synthesized conveniently by reactions involving etherification of 1,1′-(1,32-dotriacontanediyl)bis(3-benzyl-sn-glycerol) (1) with (7R,11R)-3,7,11,15-tetramethyl-2-hexadecenyl bromide and hydrogenation of the resulting unsaturated ether with p-tolylsulfonylhydrazine; a total yield from 1, 7–10%. Unlike usual monopolar double-chain-amphiphiles, the bipolar lipid bent into a U-form in a water–air interface to produce the Langmuir membrane, exhibiting peculiar surface pressure–surface area isotherms.
Syntheses and Properties of Dimethyl and Tetramethyl Anthra[1,9-cd : 4,10-c′d′]bis[1,2]dichalcogenoles and Their Charge-Transfer Complexes
Authors: Takimiya Kazuo , Aso Yoshio , Otsubo Tetsuo , Ogura Fumio
Published: July 2006

The dimethyl and tetramethyl derivatives of a series of anthra[1,9-cd : 4,10-c′d′]bis[1,2]dithiole, diselenole, and ditellurole have been prepared as a new type of electron donor. The introduced methyl groups serve to enhance not only the donor strength, but also the solubility, enabling a ready formation of their charge-transfer complexes with various electron acceptors such as 7,7,8,8-tetracyanoquinodimethane (TCNQ), its 2,3,5,6-tetrafluoro derivative, 2,5-dimethyl derivative (DMTCNQ), 2,5-dimethoxy derivative (DMOTCNQ), 2,6-bis(dicyanomethylene)-2,6-dihydronaphthalene (TNAP), 3,3′-dichloro-5,5′-bis(dicyanomethylene)-Δ2.2′-bi(3-thiolene) (DCBT), and 3,3′-dibromo-5,5′-bis(dicyanomethylene)-Δ2.2′-bi(3-selenolene) (DBBS). Although the resulting complexes are mostly 1:1 stoichiometrical, the TCNQ complexes tend to favor a composition rich in acceptors; on the contrary, the DMTCNQ and DMOTCNQ complexes tend to favor a composition rich in donors. Their electrical conductivities range widely from 8 to 10−9 S cm−1, being apparently dependent on appropriate combinations of the donors and the acceptors. In general, the present donors have a tendency to form highly conductive complexes with TCNQ, TNAP, DCBT, and DBBS. These highly conductive complexes mostly show a broad electron absorption in the infrared region, being characteristic of a segregated stacked structure in a mixed valence state. On the other hand, the X-ray analyses of DMTCNQ complexes of 3,4-dimethyl, 8,9-dimethyl, and 3,4,8,9-tetramethylanthra[1,9-cd : 4,10-c′d′]diselenoles and 3,4,8,9-tetramethylanthra[1,9-cd : 4,10-c′d′]dithiole have revealed that all of the crystal structures have mixed stack columns of donor–donor–acceptor type. Of them, the 3,4-dimethyl derivative complex shows an unusually high conductivity (0.53 S cm−1) for a mixed stacked structure, which is considered to be due to strong heteroatomic interactions of the intra- and inter-columns.
Structural Studies of a Liquid Crystalline Compound, 2-(4-Cyanophenyl)-5-(4-butylphenyl)-1,3,2-dioxaborinane, by Means of Nuclear Magnetic Resonance and X-Ray Analyses
Authors: Matsubara Hiroshi , Tanaka Takanori , Takai Yoshio , Sawada Masami , Seto Koji , Imazaki Hideyuki , Takahashi Shigetoshi
Published: July 2006

The crystal and molecular structure of the title nematogen (1), has been determined by an X-ray analysis. Compound 1 belongs to the triclinic system with space group P-1, a=9.798(2), b=11.579(2), c=9.716(2) Å, α=74.081(13), β=117.766(14), γ=108.179(13)°, and with two molecules in the unit cell. The geometry around the boron atom is planar, and the plane defined by O2BC is parallel to the phenyl ring bonded to the boron atom. The angle between two phenyl rings is 74.3°. The molecules are in their most extended conformation, with nearest neighbors oriented antiparallel to each other. The 1H NMR studies have indicated that the half-chair conformation of the dioxaborinane is kept in a solution even at 125°C where 1 forms a nematic phase, and the rigidity is essential for the formation of mesophases.
Amidoselenation of Olefins Using p-Toluenesulfonamide as a Nitrogen Nucleophile
Authors: Toshimitsu Akio , Kusumoto Takehiro , Oida Tatsuo , Tanimoto Shigeo
Published: July 2006

The reaction of olefins, benzeneselenenyl chloride, and p-toluenesulfonamide in the presence of zinc(II) chloride affords N-[2-(phenylseleno)alkyl]-p-toluenesulfonamides in good to excellent yields. When combined with alkylation on the carbon atom bearing the phenylseleno group thus introduced and subsequent oxidative or reductive removal of the selenium moiety, this reaction can be utilized in the preparation of a wide range of allylic or saturated amides.
1-Chloroalkyl p-Tolyl Sulfoxides as Acetylide Anion Equivalent: A Novel Synthesis Including Asymmetric Synthesis of Propargylic Alcohols from Carbonyl Compounds
Authors: Satoh Tsuyoshi , Hayashi Yasumasa , Yamakawa Koji
Published: July 2006

Addition of the carbanion of 1-chloroalkyl p-tolyl sulfoxide to carbonyl compounds gave the adducts, which were heated in refluxing toluene or xylene to give vinyl chlorides in high overall yield. Dehydrochlorination of the vinyl chlorides with excess n-BuLi afforded propargylic alcohols in high yields. Asymmetric synthesis of both enantiomers of the propargylic alcohols was realized using optically active 1-chloroalkyl p-tolyl sulfoxide and aldehyde.
Mechanism of Production of Singlet Oxygen on Photoexcitation of Drugs Inducing Photosensitivity
Authors: Arai Tatsuo , Nishimura Yoshinobu , Sasaki Masako , Fujita Hitoshi , Matsuo Itsuro , Sakuragi Hirochika , Tokumaru Katsumi
Published: July 2006

The mechanism and active species of drug-induced photosensitive reactions were investigated by measuring the absorption spectra of the transient species on photoexcitation as well as by determining the efficiency of singlet oxygen production on quenching by oxygen of the excited state of drugs. The quantum yields of singlet oxygen production were determined for chlorpromazine hydrochloride, mequitazine, and afloqualone as 0.27, 0.28, and 0.14, respectively. These rather high yields of singlet oxygen suggest its important role in photosensitivity of the drugs. On the basis of the transient-spectroscopic investigations the quenching mechanism of excited-state drugs by oxygen was discussed.
β-α Photoisomerization of Cobaloxime Complexes in the Solid State. III. Accelerated Reaction Rate by Hydrogen Bond
Authors: Sekine Akiko , Ohashi Yuji
Published: July 2006

The crystal structures of two cobaloxime complexes with different axial base ligands have been determined by X-ray analysis at room temperature. I: (3-Aminopyridine)(2-cyanoethyl)bis(dimethylglyoximato)cobalt(III); the cystal is monoclinic, the space group being C2⁄c, Z=8 with a=28.849(8), b=7.746(2), c=18.429(5) Å, and β=105.71(3)°. II: (Aniline)(2-cyanoethyl)bis(dimethylglyoximato)cobalt(III) aniline solvate; the crystal is monoclinic, the space group being P21⁄c, Z=4 with a=14.228(7), b=11.426(4), c=14.178(3) Å, and β=91.92(3)°. Both structures were refined by a full-matrix least-squares method to final R values of 0.070 and 0.074 for 3886 and 3311 observed reflections, respectively. Their photoisomerization rates in the solid state obtained from changes in the IR spectra, 3.2 and 4.2×10−4 s−1, respectively, are significantly greater than those of the related compounds. The hydrogen bonds between the reactive 2-cyanoethyl groups and the atoms of the neighboring molecules in the two crystals should be responsible for the greater reaction rates. Taking into account the role of the hydrogen bonds, a probable isomerization mechanism is proposed.
Characterization of Molecular-Sieving Carbon for CO2-Adsorbers in Controlled Atmosphere Storage System
Authors: Tanahashi Ichiro , Nakama Hiroto , Nishino Atsushi , Takeda Jun
Published: July 2006

Molecular sieving carbon (MSC) has been characterized for CO2-adsorbers in a controlled atmosphere storage (CA storage) system by a gas-adsorption method. Experimental data were analyzed by means of the Dubinin-Astakhov equation, the t-method, and the micropore analysis method. The BET surface area of MSC was 592 m2 g−1. In the pore size distribution curve of MSC, the most common pore diameter was 0.68 nm. The temperature and the space velocity dependence of adsorbers with MSC have been investigated. The CO2 adsorption capacity of adsorbers was determined by the gas-flow method. The capacity of the adsorbers at 60°C decreased to 55%, compared with that at 20°C; it decreased with increasing space velocity.
Silicon Effects. II. Structure and Stability of 1-Phenyl-2-(trimethylsilyl)ethyl Cation in Solution
Authors: Shimizu Nobujiro , Watanabe Shin-ichiro , Tsuno Yuho
Published: July 2006

Solvolysis rates have been measured in various solvents at 25°C for 1-(substituted phenyl)-2-(trimethyl-silyl)ethyl trifluoroacetates (1a–1g; R=H, 4-Me, 4-Cl, 4-Br, 3-Cl, 3,4-Cl2, and 3,5-Cl2, respectively) and structurally related compounds, 1-phenylethyl-, 3,3-dimethyl-1-phenylbutyl-, and 1-(4-methylphenyl)ethyl trifluoroacetates (3a, 4, and 5). In dioxane/water mixtures 1g solvolyzes with the same sensitivity to the change in solvent ionizing power as that for a kc substrate 5. The solvolyses of 1e and 5 exhibit almost identical α-deuterium kinetic isotope effects (kH⁄kD) of 1.18–1.19 in aq dioxane. Substituent effect on the solvolysis of 1 in 90% aq dioxane is expressed by an LArSR equation: logkX⁄kH=−3.05 (σ°+1.05Δ\barσR+) (R=0.9997). These findings are consistent with kc mechanism for the solvolysis of 1. Relative rates for the solvolysis of 1a, 3a, and 4 in 30% aq dioxane are 2.99×105 : 2.84 : 1.0 indicating solvolytic generation of α-(trimethylsilylmethyl)benzyl cation to be about 7 kcal mol−1 energetically more favorable than that of the corresponding α-alkylbenzyl cations.
Photochemical Trifluoromethylation of 1-Methylimidazoles and 1-Methylpyrroles Containing Methylthio Groups
Authors: Nishida Masakazu , Kimoto Hiroshi , Fujii Shozo , Hayakawa Yoshio , Cohen Louis A
Published: July 2006

The title reaction was achieved by UV (254 nm) irradiation with CF3I. The methylthio group was introduced to increase electron density and to limit available reactive sites in the rings. Following trifluoromethylation, the methylthio groups were readily removed by hydrogenolysis (Raney Ni) to give the desired trifluoromethyl heterocycles.
A Synthesis of 5′-O-Acryloyl-5-fluorouridine by Use of p-Methoxybenzyl Group as an N3-Imide Protecting Group of 5-Fluorouridine
Authors: Akiyama Takahiko , Takesue Yasuhiro , Kumegawa Masahiro , Nishimoto Hiroyuki , Ozaki Shoichiro
Published: July 2006

5′-O-Acryloyl-5-fluorouridine was prepared by use of p-methoxybenzyl (PMB) group as an N3-imide protecting group of 5-fluorouridine. PMB group was introduced chemoselectively by use of N,N-diisopropylethylamine or DBU as a base. A new deprotection method was developed by means of AlCl3–anisole system at room temperature.
CO Hydrogenation over TiO2-Supported Ultrafine Fe3O4 Particle Catalysts Prepared by a Colloid Chemical Method
Authors: Chang Byong-tae , Kim Sung-jin
Published: July 2006

The properties of TiO2 supports and the H2 reduction temperature of Fe3O4/TiO2 catalysts were found to play imortant roles in determining their activity and light olefin selectivity. For each catalyst, a good linear relationship was observed between the CO conversion and the light olefin selectivity. The sequence of the latter under identical conditions was JRC-TIO-5>TIO-3>TIO-4.
A Theorem on p-Densities in the Hückel Model of Linear Chains
Authors: Isihara Makoto
Published: July 2006

The hyperivial condition upon p-densities is applied to the simple Hiickel model of linear chains. The invariance of the modified p-density is derived in fully generalized form. Any bond order between nonadjacent sites is shown expressible in terms of two electron densities or two bond orders between adjacent sites.
Intercalation of Enzymes in γ-Titanium(IV) Phosphate
Authors: Kanzaki Yasushi , Abe Mitsuo
Published: July 2006

The intercalation of enzymes with molecular weights of 23000–240000 was examined for layered inorganic compounds. The intercalation of papain and catalase into γ-type titanium(IV) phosphate was achieved by coexisting pro-pylamine in an aqueous medium. The intercalation compound of papain was enzyme active for N-benzoyl-l-arginine ethyl ester and a catalase intercalation compound for H2O2 decomposition.
Synthesis of d-Altrose via d-Altrosan from Levoglucosenone
Authors: Matsumoto Katsuya , Ebata Takashi , Koseki Koshi , Kawakami Hiroshi , Matsushita Hajime
Published: July 2006

The stereoselective reduction and cis-dihydroxylation of levoglucosenone (1,6-anhydro-3,4-dideoxy-β-d-glycero-hex-3-enopyranos-2-ulose), gave d-altrosan (1,6-anhydro-β-d-altropyranose), which could be converted to d-altrose in high yield.
Emission Spectra of Fluorobenzenes by Controlled Electron Impact
Authors: Fukuzumi Takahiro , Nakashima Keiji , Ogawa Teiichiro
Published: July 2006

The fluorescence emission spectra of fluorobenzene, p-difluorobenzene and hexafluorobenzene excited in collisions with electrons were measured for the study of the dynamics of the exciting aromatic system. These spectra showed a band assignable to the S1→S0 transition of the parent molecule. The bands of fluorobenzene and p-difluorobenzene were intense and showed a pronounced vibrational structure and the intense vibrational transitions were optically allowed. Whereas, that of hexafluorobenzene was broad and weak and did not show any clear vibrational structure.
Combustion Reactions in Silane–Air Flames I. Flat Premixed Flames
Authors: Fukutani Seishiro , Uodome Yasuhiro , Kunioshi Nílson , Jinno Hiroshi
Published: July 2006

In this work the combustion mechanism of silane–air flames is elucidated through a simulation employing a detailed chemical scheme. Two different pathways for the consumption of silane were found: SiH4→SiH3→SiH2O→HSiO, which proceeds in low-temperature regions, and SiH4→SiH2→HSiO, occurring at high temperatures; this supports results previously reported in the literature. It was also found that some reactions occur over wide ranges of temperature and that the governing step for the whole silane combustion is the reaction of silane with hydroxyl radicals. A least square fitting to the burning velocities and adiabatic flame temperatures obtained for the four investigated mixtures, with equivalence ratios of 2.0, 1.43, 1.0, and 0.5, indicated that a mixture with equivalence ratio of about 1.2 would have the largest burning velocity and the highest flame temperature.
Combustion Reactions in Silane–Air Flames II. Counterflow Diffusion Flame
Authors: Fukutani Seishiro , Kunioshi Nílson , Uodome Yasuhiro , Jinno Hiroshi
Published: July 2006

A detailed chemical reaction scheme and a full set of governing equations for fluid dynamics were used to elucidate the chemical and physical phenomena involved in a silane–air counterflow diffusion flame, where the fuel and air issue from the lower and upper nozzles, respectively. It was found that a stagnation surface, where the axial velocities fall down to zero, is kept in a position slightly shifted to the upper side, dividing the system into two zones: the upper air side and the lower fuel side; after leaving the nozzle silane begins to dissociate itself into SiH2 and H2 when it reaches the region of rising temperature; oxygen penetrates into the fuel side by diffusion and reacts with H2 forming OH radicals and H atoms. The produced SiH2 is further dehydrogenated to SiO via HSiO; comparing with premixed flames, the diffusion flames have large local equivalence ratios, so that the combustion reactions in the latter flames occur through a different mechanism.
Spectrochemical Series for the Outersphere Coordination of Carboxylatocobaltate(III) Complexes with Solvent Molecules
Authors: Taura Toshiaki
Published: July 2006

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

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

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

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

(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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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.
Catalytic Functions of Artificial Enzyme Composed of Simple Vitamin B12 Model and Synthetic Bilayer Membrane
Authors: Murakami Yukito , Hisaeda Yoshio , Song Xi-Ming , Fan Sheng-Di , Ohno Teruhisa
Published: July 2006

An artificial enzyme was constructed with a combination of the single-walled vesicle of N,N-dihexadecyl-Nα-[6-(trimethylammonio)hexanoyl]-l-alaninamide bromide (N+C5Ala2C16) and a simple vitamin Bi12 model; (11-hydroxyimino-4,10-dipropyl-5,9-diazatrideca-4,9-dien-3-one oximato)cobalt, [Co(C2C3)(DO)(DOH)pn], or [N-(2-hydroxyiminocyclohexylidene)-N′-(cyclohexyliden-2-one oximato)-1,3-diaminopropane]cobalt, [Co(ch)(DO)(DOH)pn]. Carbon-skeleton rearrangement reactions of alkyl ligands bound to the cobalt complex were markedly favored in the single-walled vesicle, relative to the reactions in methanol and benzene, under anaerobic photolysis conditions at ordinary temperatures. The cobalt complex incorporated into the intramembrane domain is subjected to significant repression of its molecular motion and to desolvation as confirmed by fluorescence and fluorescence polarization measurements. The 1,2-migration of cyano and carboxylic ester groups involved in the alkyl ligands is plausibly enhanced by such effects.
Substituent Effect in o-Nitroperbenzoic Acid Oxidation of m- and p-Substituted Acetophenones
Authors: Token Katsuo , Hirano Kenji , Yokoyama Tai , Goto Katsumi
Published: July 2006

The Baeyer–Villiger reaction of m- and p-substituted acetophenones (substituents: H, p-MeO, p-t-Bu, p-i-Pr, p-Et, p-Me, p-Cl, p-Br, m-MeO, m-Me, m-Cl) with o-nitroperbenzoic acid was studied in chloroform at 30°C. The rate constants for the general acid catalysis were measured at several concentrations of o-nitrobenzoic acid which acted as an acid catalyst. The uncatalyzed and acid-catalyzed rate constants obtained afforded ρ values of −2.16 and −4.11 with σ, respectively. The results indicated that the rate-determining step is the migration of the phenyl group in the peroxy acid-carbonyl adduct for all the substituents studied, whether the reaction is acid-catalyzed or not, and that the acid catalyst intervenes only in the formation of the acid-ketone adduct in the initial state and not in the migration step. The variation of the leaving group abilities required the variation of the substituent constants applied, whereas the acid intervention in the addition step was reflected only in the variation of the ρ value, not in the substituent constants to be applied. The smaller resonance demand for o-nitroperbenzoic acid indicated that the structure of the transition state in the migration step was looser and that the position of the transition state was earlier than those for m-chloroperbenzoic acid.
Molecular Structures of Trichlorovinyl(p-tolyl)nickel(II) Complex, and Its Thermal and Photo Isomerization Products
Authors: Chen Jie , Kai Yasushi , Kasai Nobutami , Wada Masanori , Kumazoe Makoto
Published: July 2006

The molecular structure of the trichlorovinyl(p-tolyl)nickel(II) complex (trans-[Ni(CCl=CCl2)(C6H4Me-4)(PMe3)2] (1)), its thermal isomerization product (trans-[NiCl{C(C6H4Me-4)=CCl2}(PMe3)2] (2)) and one of its photolysis products (trans-[NiCl{CCl=CCl(C6H4Me-4)}(PMe3)2] (3)) have been determined by an X-ray diffraction method. Crystal data: 1; triclinic, space group P\bar1, a=8.768(1), b=9.347(1), c=13.029(2) Å, α=103.79(2), β=96.23(2), γ=86.90(3)°, V=1030.4(3) Å3, Z=2, Dc=1.393 g cm−3, 2; orthorhombic, space group P212121, a=13.884(2), b=14.505(3), c=10.272(2) Å, V=2068.6(6) Å3, Z=4, Dc=1.388 g cm−3, 3; triclinic, space group P\bar1, a=11.628(4), b=8.975(3), c=10.437(4) Å, α=102.91(3), β=99.45(3), γ=89.91(4)°, V=1046.6(7) Å3, Z=2, Dc=1.377 g cm−3. Molecules 2 and 3 were found to contain p-totly group on the α-carbon and β-carbon atoms of the vinyl ligand, respectively. Intersting structural deformations were found in 1.
Synthesis, Structure, and NMR Spectra of [Cu2(phen)2(μ-(C6H5)2PCH2P(C6H5)2)2](PF6)2 and Its Derivatives
Authors: Kitagawa Susumu , Maruyama Hideki , Wada Shigetoshi , Munakata Megumu , Nakamura Masaki , Masuda Hideki
Published: July 2006

The bis(diphenylphosphino)methane(dppm) compounds of copper(I), [Cu2(μ-dppm)2(biL)2](PF6)2 (biL=1,10-phenanthroline and its derivatives), have been synthesized and characterized by 1H and 31P NMR spectroscopy and X-ray crystallography. The molecules are found to contain a [Cu2(dppm)2]2+ framework with the two copper atoms bridged by two dppm ligands to give eight-membered C2P4C2 rings. This framework shows a staggered conformation subject to the coordination of additional ligands, biL. The coordination 1H and 31P shifts of the dppm are well-correlated with the basicity of the nitrogen donor atom of biL, sensitive to variations in the copper-ligand binding as well as their metal-to-ligand charge-transfer band. Crystallographic data of [Cu2(dppm)2(phen)2] are as follows, monoclinic space group P21⁄c, a=11.515(2) Å, b=27.922(4) Å, c=12.493(2) Å, β=107.68(1)°, U=3827(1) Å3, and Z=2.