bluuebunny/crossref_metadata_2025_split huggingface dataset:
Crystal and Molecular Structure of [2-(2-Benzoxazolyl)phenolatotetrachloroplatinum]·[2-(2-Benzoxazolyl)phenol]·Ethanol, [PtCl4-(C13H8O2N)]·(C13H9O2N)·C2H5OH: Possibly a Stable New Pentavalent Platinum Complex
Authors: Furuhashi Akiko , Ono Isao , Ouchi Akira , Yamasaki Akira 
Published: July 2006

Abstract
The crystal and the molecular structures of the title complex were determined by means of the single-crystal X-ray diffraction method. The crystal of PtC28H23O5N2Cl4, F. W. 804.40, (black-violet in color) is monoclinic, with the space group of P21⁄a, a=18.293(4), b=9.682(2), c=15.797(3) Å, β=96.55(2)°, U=2779.6(9) Å3, Z=4, Dm=1.90, Dx=1.92 g cm−3, and μ (Mo Kα)=57.37 cm−1. The platinum atom is in a hexa-coordinated octahedral geometry, where one 2-(2-benzoxazolyl)phenolate (bxp−) ion is chelated with its N and phenolato O atoms. The bxp− ligand as well as the free Hbxp molecule are both approximately planar, and their planes are approximately in parallel: They are arranged alternately and are laid roughly along the a-axis. Although the overlappling areas of the neighboring rings are only 23 and 13% respectively of the whole ring area, the interplane distances are 3.42 and 3.49 Å.
Local Structure, Tg, and IR Transparency of Potassium Titanate Glasses and the Local Structure of Calcium Titanate Ceramics
Authors: Nishida Tetsuaki , Yamaguchi Yasuharu , Yamada Miho , Takashima Yoshimasa 
Published: July 2006

Abstract
The Mössbauer spectrum of xK2O·(95−x)TiO2·5Fe2O3 glasses (x=35–60), consisting of a paramagnetic doublet peak due to tetrahedral Fe3+, suggests that the Fe3+ is substituted for the tetrahedral Ti4+. The isomer shift (δ=0.20–0.23 mm s−1) and the quadrupole splitting (Δ=0.72–0.81 mm s−1) decrease linearly with the increasing K2O content. The glass transition temperature (Tg) decreases similarly as the Δ does, supporting the “Tg−Δ rule” discovered by Nishida et al., i.e., the Tg of oxide glasses is expressed by Tg=aΔ+b. (The slope “a” is 680 °C mm−1 s.) The IR absorption spectra show two peaks at 880 and 640 cm−1 corresponding to the Ti(Fe)O4 and TiO6 units, respectively. The relative absorption intensity of the Ti(Fe)O4 units becomes higher when the K2O content increases. The potassium titanate glasses (plate) show IR transparency, having the transmission edge of 5.4 μm. The Mössbauer spectrum of xCaO·(95−x)TiO2·5Fe2O3 ceramics (x=5–50) consists of two doublet peaks due to Fe3+ and Fe2+. Both the δ and Δ of the Fe3+ are constant irrespective of the CaO content, whereas the fraction (relative absorption area) of the Fe3+ decreases linearly from 94 to 75% when the CaO content is increased from 5 to 50 mol%.
Dynamic NMR as a Nondestructive Method for the Determination of Rates of Dissociation. XVIII. Factors Affecting the Rates of Dissociation of N–B Bond in the Coordinated Form of 9-[2-(Dialkylaminomethyl) phenyl]-9-borabicyclo[3.3.1] nonanes
Authors: Toyota Shinji , Oki Michinori 
Published: July 2006

Abstract
NMR spectra of the title compounds reveal that they exist in the intramolecularly N–B coordinated form. The NMR signals exhibited dynamic behaviors accompanied with the dissociation of the N–B bond and total line shape analyses of the exchanging nuclei afforded kinetic parameters for the topomerization. Entropies of activation are large and positive, typical for the dissociation of coordination bonds. Examination with the multiple probes shows that the nitrogen inversion requires additional energy after the N–B bond dissociation. The barrier for the topomerization is affected by N-alkyl groups due to their F-strain. The barrier height is reduced in nonpolar solvents and not influenced by nucleophilicity of solvents. These solvent effects are discussed in connection with polarity of the N–B bond and steric hindrance of the boron atom.
Dynamic NMR as a Nondestructive Method for the Determination of Rates of Dissociation. XIX. Sulfur Inversion in 9-[2-(Ethylthiomethyl)phenyl]-9-borabicyclo[3.3.1]nonane Proceeds via Dissociative Mechanism
Authors: Toyota Shinji , Oki Michinori 
Published: July 2006

Abstract
Kinetic parameters for sulfur inversion in the title compound were determined by the dynamic NMR method in CD2CL2 as follows: ΔH≠ 14.2±0.1 kcal mol−1, ΔS≠ 11.3±0.3 cal mol−1 K−1, ΔG233≠ 11.6 kcal mol−1. The large and positive entropy of activation suggests that the inversion takes place through dissociative mechanisms. Comparison of the rate constants obtained with multiple probes shows that the rotation about the Cph–B bond requires further energy after the dissociation of the S–B bond. The solvent effect on the sulfur inversion is small but distinct; the more polar a solvent, the higher the barrier to the inversion. Dynamic behaviors of a related compound are also discussed.
Nucleophilic Ring-Opening of Chlorooxiranes: A New Synthesis of α-Hydroxy α′-Substituted Ketones from Carbonyl Compounds and 1-Chloroalkyl p-Tolyl Sulfoxides
Authors: Satoh Tsuyoshi , Ogura Asako , Ikeda Youko , Yamakawa Koji 
Published: July 2006

Abstract
The addition of 1-chloroalkyl p-tolyl sulfoxides to carbonyl compounds gave adducts which were then converted to chlorooxiranes in two steps with good overall yields. The treatment of the chlorooxiranes with various nucleophiles gave α-hygroxy α′-substituted ketones or α-hydroxy ketones in good yields.
Nucleophilic Substitution Reactions between Diphosphonate and Orthophosphate Characterized by High-Performance Liquid Chromatography and 31P NMR Spectroscopy
Authors: Yoza Norimasa , Okamatsu Miki , Tokushige Noriko , Miyajima Tohru , Baba Yoshinobu 
Published: July 2006

Abstract
Inorganic diphosphonate with phosphorus of an oxidation number +3 was found to react with orthophosphate (oxidation number +5) at 50 °C to give phosphonylated compounds; dimeric isohypophosphate (oxidation numbers +3 and +5) and a novel trimeric compound (oxidation numbers +3 and +5). Orthophosphate ion is considered to act as a ligand with two or three nucleophilic sites that were phosphonylated stepwise by diphosphonate. Kinetic processes of the nucleophilic reactions were monitored by HPLC and 31P NMR. Two products, the dimer having one P–H bond and the trimer with two P–H bonds, were well-resolved by HPLC and their yields, based on orthophosphate applied, were 85% (dimer) and 3% (trimer) when a mixed solution of 0.5 M diphosphonate and 0.1 M orthophosphate was incubated at 50 °C for 21 h. A complicated 31P NMR spectrum that indicated a large coupling constant(JPH=650 Hz) and grew with incubation time is reasonably assigned to the unsymmetrical isohypophosphate composed of both a phosphate group and a phosphonate group. Apparent formation constants of the dimer and trimer were evaluated.
Intramolecular Energy Transfer in Covalently Linked Polypyridine Ruthenium(II)/Osmium(II) Binuclear Complexes. Ru(II)(bpy)2Mebpy– (CH2)n–MebpyOs(II)(bpy)2 (n=2, 3, 5, and 7)
Authors: Furue Masaoki , Yoshidzumi Toshiyuki , Kinoshita Shuichi , Kushida Takashi , Nozakura Shun-ichi , Kamachi Mikiharu 
Published: July 2006

Abstract
A novel series of polymethylene-linked heterobinuclear complexes of polypyridine ruthenium(II)/osmium(II) complex Ru(II)(bpy)2Mebpy–(CH2)n–MebpyOs(II)(bpy)2(bpy=2,2′-bipyridine and n=2, 3, 5, and 7), 1, was prepared. The photophysical behavior was examined in various solvents. The emission spectra of 1 (excitation wavelength: 455nm) showed a nearly complete quenching of RuII→π*(bpy) metal-to-ligand charge transfer (MLCT) emission and the enhancement of OsII→π*(bpy) MLCT emission. The luminescence lifetime measurements by a time-correlated single photon-counting method provided evidence that intramolecular energy transfer is a significant pathway for the observed emission quenching. The rate constants of the intramolecular energy transfer in ethanol are 5.3×108, 3.3×108, 1.3×108, and 1.0×108s−1 for 1(n=2, 3, 5, and 7), respectively. They were found to be proportional to the inverse sixth power on the center-to-center distance of the two complexes. The mechanism is discussed in terms of the Förster (a dipole-dipole interaction) mechanism.
Methanol Synthesis from CO2 and H2 over CuO–ZnO Catalysts Combined with Metal Oxides under 13 atm Pressure
Authors: Xu Zheng , Qian Zaihu , Mao Liqun , Tanabe Kozo , Hattori Hideshi 
Published: July 2006

Abstract
The synthesis of methanol from CO2 and H2 in a flow reactor was studied over CuO–ZnO catalysts combined with ZrO2, MgO, Al2O3, or Cr2O3 under a presssure of 13 atm. CuO–ZnO–Al2O3, CuO–ZnO–ZrO2, and CuO–ZnO–MgO showed higher activity and higher selectivity for methanol than did CuO–ZnO. The selectivity for methanol formation became higher as the reaction temperature was lower, or any of the H2/CO2 ratio, the pressure and the space velocity were higher. On the basis of analyses by XRD, XPS, and ultraviolet diffused reflectance spectroscopy, the active centers of CuO–ZnO–ZrO2 seem to be a Cu+–ZnO species stabilized by ZrO2.
Support Effect of Re Catalyst on Methanol Synthesis from CO2 and H2 under a Pressure of 5 atm
Authors: Xu Zheng , Qian Zaihu , Tanabe Kozo , Hattori Hideshi 
Published: July 2006

Abstract
Methanol synthesis by the reaction of CO2 with H2 over Re supported on ZrO2, CeO2, La2O3, and Al2O3 was studied under a pressure of 5 atm by the use of a flow reactor. Methanol was formed over Re/CeO2, Re/ZrO2, and Re/La2O3, but not over Re/Al2O3 and ZrO2 alone. On the basis of XPS analysis, the active state of Re was suggested to be Re0 for Re/ZrO2 and Re/CeO2. For Re/Al2O3, Re was incompletely reduced, resulting in no formation of methanol. Methanol synthesis was inferred to proceed via CO in the case of Re/ZrO2, and via the reaction of CO2 with surface OH in the case of Re/CeO2 by FT-IR analysis.
UV and DSC Analyses of Suspensions of Mixtures of Phosphatidylcholine and a Fatty Acid Having a Diene Group
Authors: Hasegawa Etsuo , Hatashita Masanori , Kimura Noboru , Tsuchida Eishun 
Published: July 2006

Abstract
The aqueous suspensions of the mixtures of a phosphatidylcholine (1,2-Bis[(2E,4E)-2,4-octadecadienoyl]-sn-glycero-3-phosphocholine (1b) and 1,2-dioctadecanoyl-sn-glycero-3-phosphocholine (1a)) with a fatty acid ((2E,4E)-2,4-octadecadienoic acid and octadecanoic acid), having a diene chromophore were analyzed by DSC and UV measurements. The phase transition was dependent on the composition of the lipid mixtures. The UV spectral change of the diene chromophore of a fatty acid for the 1a mixtures corresponded well with the phase transition determined by DSC analyses, but not for the 1b mixtures.
Terminal Polar Substituent Effect on the Liquid Crystalline Properties of a Series of 4-Octyloxy-N-(4-substituted benzylidene)anilines
Authors: Miyajima Seiichi , Enomoto Takehiko , Kusanagi Tomohiro , Chiba Takehiko 
Published: July 2006

Abstract
Mesomorphic properties are studied on the title compounds where substituents are F, Cl, Br, I, NO2, and CN. Besides the known mesophases, nematic and smectic Ad, in CN and NO2 homologues, stable smectic A and B phases were observed in either of the Cl and Br derivatives. Metastable nematic and smectic A phases were found in F derivative. The effects of terminal polar substituents, stabilization of the smectic A phase by moderately polar substituents, and of the nematic phase by strongly polar substituents, were confirmed.
Synthesis and Characterization of Six-Membered Cyclometallated Complexes of 2-Bezylpyridine with Rhodium(III)
Authors: Hiraki Katsuma , Onishi Masayoshi , Kishino Hiroko 
Published: July 2006

Abstract
2-Benzylpyridine (Hpiph) is metallated with RhCl3·3H2O to give [{Rh(piph)Cl2(Hpiph)}2]·H2O [piph=2-(2-picolyl)phenyl] in which piph is coordinated at phenyl-1-C and picolyl-N atoms. This complex reacts with tertiary phosphines (PR3) such as PEt3, PEt2Ph, and PPh3 to yield [Rh(piph)Cl2(PR3)2].
Catalytic Behavior of Rhodium(I) Complexes in Hydrogermylation and Hydrosilylation of Phenylacetylene
Authors: Wada Fumio , Abe Seiji , Yonemaru Norio , Kikukawa Kiyoshi , Matsuda Tsutomu 
Published: July 2006

Abstract
Rhodium complexes, Rh(L)(C2H4)2 {L=(CH3C=O)2CH (acac), and (CF3C=O)2CH (hfa)}, catalyze hydrogermylation and hydrosilylation of phenylacetylene with Bu3GeH and R3SiH (R=Bu, Et), respectively, to produce Ph(R3M)C=CH2 (M=Ge, Si) selectively. Other rhodium complexes, that is, [RhCl(C2H4)2]2, Rh2Cl2(cod)2, Rh(tmhd)(C2H4)2 {tmhd=(t-BuC=O)2CH}, and Rh(dbm)(C2H4)2 {dbm=(PhC=O)2CH}, also catalyze these reactions, but with less regioselectivity.
Aggregates in Langmuir–Blodgett Films of Spiropyrans Having Hydroxyl or Hydroxymethyl Group
Authors: Miyata Akio , Unuma Yutaka , Higashigaki Yoshiyuki 
Published: July 2006

Abstract
The optical properties of monomolecular layers at an air–water interface and also of Langmuir–Blodgett (LB) films of several photochromic spiropyrans with a single hydrophobic long chain and either a hydroxyl or a hydroxymethyl group have been investigated. Changes in the optical spectra of these films were induced by either UV irradiation or heating. UV-visible, and IR absorption spectra showed that spiropyran SP145 formed J-aggregates and SP147 formed H-aggregates. The half-decay period of the J-aggregate to the spiropyran (SP) form was longer than that of the colored monomeric photomerocyanine (PMC) to the SP form. It was concluded that hydrogen bonding between neighboring colored PMC molecules via hydroxyl, hydroxymethyl, and nitro groups stabilizes the aggregate state.
Shock Tube Studies of the H2–O2–CO Reaction by Atomic Resonance Absorption Spectroscopy
Authors: Koike Tohru 
Published: July 2006

Abstract
The atomic resonance absorptions of O- and H-atoms in the reaction of shock-heated H2/O2/CO/Ar(1/1/1/97 and 0.2/1/1/97.8) mixtures were observed over a relatively low temperature range from 1000 to 1400 K. The induction times, determined from the absorptions, were investigated by means of computer modeling which included a sensitivity test. The rate constant for the important initiation reaction, CO+O2=CO2+O, was evaluated to be k13=1013.1±0.6exp (−196.9±14.9kJ⁄RT) cm3 mol−1 s−1, which may supplement the lack of reported rate constants in the low-temperature region.
Formations of OH(X2II, A2Σ+) in the Reaction of NH(3Σ−) with NO in Incident Shock Waves
Authors: Yokoyama Keiichi , Sakane Yasuo , Fueno Takayuki 
Published: July 2006

Abstract
Gaseous mixtures of HNCO and NO diluted in Ar were heated by incident shock waves to about 3500 K to investigate the bimolecular reaction of NH(3Σ−) with NO. Ultraviolet emissions from the excited NH(A3II) and OH(A2Σ+) were monitored to determine the rate constants for the ground-state reaction NH(3Σ−)+NO→N2+OH(X2II). The branching ratio defined as the rate constant for the formation of OH relative to that for the NH(3Σ−) decay was found to be 0.32±0.07 at the shock-wave temperature adopted. An intense spike of chemiluminescence due to OH(A2Σ+→X2II) was observed, a finding which indicates a possible participation of the channel NH(3Σ−)+NO→N2+OH(A2Σ+) at high temperatures.
Titanium(III) Chloride Mediated Reduction of 1-Nitro-2-phenylethenes
Authors: Sera Akira , Fukumoto Shoji , Tamura Masako , Takabatake Kiyoshi , Yamada Hiroaki , Itoh Kuniaki 
Published: July 2006

Abstract
The reaction of 1-nitro-2-phenylethenes (β-nitrostyrenes) with aqueous titanium(III) chloride afforded substituted pyrroles in addition to the expected reduction products, oximes and carbonyl compounds. 2-Substituted 1-nitro-2-phenylethenes yielded divinylamine derivatives instead of pyrroles. The reaction mechanism has been rationalized by taking account of the electron transfer from titanium(III) species to the nitro olefins, followed by protonation, dimerization, cyclization, and/or hydrolysis.
Complex Formation of Gelatin and Chondroitin Sulfate and the Effects on H+ Ion Binding
Authors: Yonese Masakatsu , Yano Mikio , Kishimoto Hiroshi 
Published: July 2006

Abstract
Soluble and insoluble complex formations of gelatin and chondroitin 6-sulfate (Chs-C) were studied by measuring their viscosities and transmittances; the effects of complex formations on H+ ion binding were studied by pH titrations. Soluble complexes were formed electrostatically with low ionic strengths; the compositions of the complexes varied with pH from those of solutions. The weight fraction of Chs-C of the saturated soluble complex was found to be 0.294 at pH=5.1. The composition of the insoluble complexes increased in the fraction of Chs-C with decreasing pH. The compositions were found to agree with the theoretical predictions obtained from the condition of electroneutrality. Furthermore, from pH titrations of mixed solutions comprising gelatin and Chs-C, the apparent dissociation constants, pKa of the carboxylic groups of both polymers were obtained. They were found to increase due to soluble complex formation; soluble complex formation depresses the dissociation of H+ ions due to a shielding of the positively charged amino groups of gelatin.
Electronic Spectra of Phenanthrolinediones, Phenanthrolinones, Bipyridinediones, and Amino-Substituted Phenanthrolines
Authors: Yamada Masaki , Kimura Miki , Nishizawa Mineyasu , Kuroda Shigeyasu , Shimao Ichiro 
Published: July 2006

Abstract
The electronic spectra of three types of 1,10-phenanthroline derivatives having different π-conjugated systems, phenanthrolinedione, phenanthrolinone, and the parent phenanthroline, showed characteristic patterns easily distinguished from each other. Analogous spectral patterns were noted in amino-substituted 1,10-phenanthrolines, and the protonated structures of these compounds were characterized on the basis of such spectral features.
Palladium-Catalyzed Vinylation of Haloazulenes and Halotropolones with Olefins. Utility of the Heck Reaction in the Conjugated Carbon Chain Preparation
Authors: Horino Hiroshi , Asao Toyonobu , Inoue Naoto 
Published: July 2006

Abstract
The reactions of 3-iodotropolone with styrenes (styrene, p-methoxystyrene, and 2-vinylpyridine), methyl acrylate, and allylic compounds (methyl 3-butenoate, 3-butenenitrile, 1-allyl-3,4-dimethoxybenzene, and 1-allyl-3,4-methylenedioxybenzene) were carried out, according to the modified Heck’s procedure, to give 3-styryl-, 3-(2-carboxyvinyl)-, and 3-(3-substituted 1-propenyl)tropolones, respectively. Similarly, 4-bromo- or 5-bromotropolone was made to react with these olefins to yield 4-styryltropolone or the corresponding 5-(2-substituted vinyl)- and 5-(3-substituted 1-propenyl)tropolones. Substitution of 2-chlorotropone by styrenes produced 2-styryltropones. Extension of the vinylation to 2-amino-6-bromoazulenes, ethyl 3-bromo-1-azulenecarboxylate, and diethyl 2-chloro-1,3-azulenedicarboxylate resulted in a similar substitution.
Syntheses, Crystal Structures, and Antitumor Activities of Dinuclear Platinum(II) Complexes, Di-μ-sulfoacetato-bis[(diamine)platinum(II)] Trihydrate
Authors: Miyamoto T Ken , Ichida Hikaru 
Published: July 2006

Abstract
A series of new dinuclear platinum(II) complexes have been prepared from the reaction of [PtL2(OH)2] with sulfoacetic acid: [PtL2(slac)]2·3H2O, where slac=sulfoacetate dianion; L2=1,2-diaminocyclohexane (1a–1c) or 1,2-diaminoethane (2) and L=isopropylamine (3) or ammine (4). They have di-μ-carboxylato bridged dinuclear zwitterionic structures in crystals. Among them, complexes (1a–1c) show significant antitumor activities against mice ieukemia L1210.
Raman Phonon Spectroscopic Study of Phase Transition in 4-Cyanopyridine Crystal
Authors: Chakrabarti Subhasis , Misra Tridibendra Marayan , Sarma Mahesh Kumar , Medhi Kanak Chandra 
Published: July 2006

Abstract
Raman phonon spectroscopy in the 10–170 cm−1 range has been used to study phase transition in 4-cyanopyridine crystal. At 77 K, ten distinct phonon modes and an internal mode are observed whereas at 300 K the spectrum shows only six phonon bands and an internal mode. The temperature dependence of spectral pattern and phonon band width suggest that the crystal goes through a phase transition around 120 K. Experimental result suggests that the phase transition is discontinuous with a small structural change.
Crystalline 1 : 1 Inclusion Complexes between a Roof-Shaped Diamide Host and Methanol or Propionic Acid. Crystal Structures and Modes of Interaction
Authors: Csöregh Ingeborg , Finge Stephan , Weber Edwin 
Published: July 2006

Abstract
The crystal structures of two inclusion complexes between anti-N-N′-di-t-butyl-9,10-dihydro-9,10-ethanoanthracene-11,12-dicarboxamide host and methanol [a=11.8893(4), b=18.0943(7), c=12.6322(4) Å, β=108.47(3)°, P21⁄c, Z=4] or propionic acid [a=11.4580(8), b=11.7614(9), c=12.4675(8) Å, α=95.37(3), β=109.70(3), γ=113.26(3)°, P\bar1, Z=2] as guests have been studied by X-ray diffraction. Closed loops of different sizes, formed via hydrogen-bond interactions between host and guest or between the hosts only, characterize both structures. The crystals with the propionic acid guest consist of hydrogen-bonded host : guest associates with 2 : 2 stoichiometry, while the methanol inclusion gives rise to infinite hydrogen-bonded chains.
Molecular Structure and Carbonylation of Ethyl(benzenethiolato)-palladium(II) Complex, trans-PdEt(SPh)(PMe3)2
Authors: Osakada Kohtaro , Ozawa Youichi , Yamamoto Akio 
Published: July 2006

Abstract
X-Ray crystallography of ethylpalladium thiolato complex, trans-PdEt(SPh)(PMe3)2, shows the detailed features of the Pd–C and Pd–S bonding. Reaction of the complex with CO at 5 atm gives S-phenyl thiopropionate. The NMR spectrum of the reaction mixture under 1 atm of CO shows the presence of trans-Pd(COEt)(SPh)(PMe3)2 formed through CO insertion into the Pd–C bond.
Urea Sensitive Field Effect Transistors Based on Dithio Group-Containing Langmuir–Blodgett Membranes
Authors: Lee Shouryu , Anzai Jun-ichi , Osa Tetsuo 
Published: July 2006

Abstract
2-(Octadecyldithio)pyridine (1) and 5-(octadecyldithio)-2-nitrobenzoic acid (2) were synthesized in order to prepare Langmuir–Blodgett (LB) membranes which possess reactive dithio groups on the surface for further modification with enzymes. The monolayer membrane, composed of 1 or 2, was deposited successfully on an ion-sensitive field effect transistor, and the membrane surface was modified with urease covalently by a thiol–disulfide exchange reaction. The LB membrane-based sensor 2 showed a better potentiometric response to urea than that of the membrane-based sensor 1. The results are discussed on the basis of the reactivity of the dithio groups to urease at the membrane surface.
Thermally Irreversible Photochromic Systems. Photoreaction of Diarylethene Derivatives with Imidazo[1,2-a]pyridine Rings
Authors: Nakayama Yasuhide , Hayashi Koichiro , Irie Masahiro 
Published: July 2006

Abstract
A non-symmetrical diarylethene with imidazo[1,2-a]pyridine ring on one end and thiophene ring on the other end, 1,2-dicyano-1-(2-methylimidazo[1,2-a]pyridin-3-y1)-2-(2,4,5-trimetyl-3-thieny1)ethene 2Z underwent a hexatriene-cyclohexadiene type reversible ring-closure reaction by photoirradiation, while an only Z–E isomerization was observed for a symmetrical diarylenthene with two imidazo[1,2-a]pyridine rings, 1,2-dicyano-1,2-bis(2-methylimidazo[1,2-a]pyridin-3-yl)ethene 1Z. The ring-closure reaction was not discerned. The photogenerated closed-ring form 2C had the absorption band at 535 nm, which is 23 nm longer wavelengths than that of the corresponding dithienylethene, and kept the absorption intensity constant for more than 24 h at 80 °C. The quantum yield close to unity was observed for the photochemical ring-opening reaction of 2C with 546 nm light.
Partition Coefficient of 21H,23H-Porphine and Its Metal(II) Complexes between Heptane and Nonaqueous Polar Solvents
Authors: Wakui Yoshito , Imura Hisanori , Suzuki Nobuo 
Published: July 2006

Abstract
The partition coefficients of 21H,23H-porphine (H2por) and its copper(II) (Cu(por)) and zinc(II) (Zn(por)) complexes were determined in nonaqueous two-phase systems. A linear free-energy relationship was observed between the partition coefficients of H2por and Cu(por). The partition coefficient of Zn(por) was suppressed by coordination bonding with the polar solvent molecules.