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71.
A fully optical remote detection system for propane gas was realized in real time by a near-infrared absorption method employing a 2-km long low-loss silica optical-fibre link in conjunction with an InGaAs light emitting diode at 1.68 μm. The detection sensitivity for propane gas in air, which was achieved to lower than 2 torr, i.e. nearly 12% of the lower explosion limit for propane, demonstrates the practical feasibility and reliability of this kind of fibre-optic remote gas sensor system with electrical and thermal safety. 相似文献
72.
Sunatsuki Y Ohta H Kojima M Ikuta Y Goto Y Matsumoto N Iijima S Akashi H Kaizaki S Dahan F Tuchagues JP 《Inorganic chemistry》2004,43(14):4154-4171
The [Fe(II)(H(3)L)](BF(4))(2).3H(2)O (1) complex was synthesized, where H(3)L (tris[[2-[(imidazole-4-yl)methylidene]amino]ethyl]amine) is a tripodal ligand obtained by condensation of tris(2-aminoethyl)amine and 4-formylimidazole (fim) in a 1:3 molar ratio. Starting from 1, a series of complexes, [Fe(II)(H(1.5)L)](BF(4))(0.5) (2) (=[Fe(II)(H(3)L)][Fe(II)(L)]BF(4)), [Fe(H(1.5)L)]BF(4) (3) (=[Fe(II)(H(3)L)][Fe(III)(L)](BF(4))(2)), [Fe(III)(H(3)L)](BF(4))(3).fim.H(2)O (4), and [Fe(III)(L)].2.5H(2)O (5), has been synthesized and characterized. The single-crystal X-ray structure of each complex has been determined. The Fe(II) compound, 2, and a mixed valence Fe(II)-Fe(III) compound, 3, involve formally hemi-deprotonated ligands, H(1.5)L. The structure of 3 consists of a homochiral two-dimensional assembled sheet, arising from the intermolecular hydrogen bonds between [Fe(II)(H(3)L)](2+) and [Fe(III)(L)](0) (3). All but 5 exhibit spin crossover between low-spin (LS) and high-spin (HS) states. This is a rare case where both Fe(II) and Fe(III) complexes containing the same ligand exhibit spin-crossover behavior. Magnetic susceptibility and M?ssbauer studies showed that 3 has three accessible electronic states: LS Fe(II)-LS Fe(III), HS Fe(II)-LS Fe(III), and HS Fe(II)-HS Fe(III). Compounds 1-3 show the light-induced excited spin-state trapping effect at the Fe(II) sites upon irradiation with green light. The solution magnetic properties, electronic spectra, and electrochemical properties of 1, 4, and 5 were also studied. 相似文献
73.
Goto M Yamamoto Y Sumimoto M Tsuruda N Kurosaki H 《Chemical & pharmaceutical bulletin》2003,51(10):1157-1162
Square-planar complexes with the formula [Pt(L(2))(L(1))](X)(2) x nH(2)O, where L(1) is S-2-aminomethylpyrrolidine (S-pyrda) or 2-aminomethylpiperidine (pipda) and L(2) is diammine (X=Cl), cyclobutane-1,1-dicarboxylato (cbdca) (X=none), 2,2'-bipyridine (bpy) (X=NO(3)), or 1,10-phenanthroline (phen) (X=Cl), were prepared and the nature of the coordination of L(1) was examined by (1)H-NMR spectroscopy and X-ray crystallography. These 2-aminomethylazacycloalkane derivatives form five-membered chelate rings condensed with an azacycloalkane ring in cis- or trans-configurations. The (1)H-NMR spectrum of complexes with S-pyrda as L(1) were consistent with cis-condensed rings in an S(N) conformation with any of L(2) group. However, (1)H-NMR spectra of the complexes with pipda as L(1) indicated trans-fused successive rings for the diammine and cbdca as L(2), but spectra for bpy and phen as L(2) were consistent with a conformation having cis-fused successive rings. X-Ray crystallography data for the two complexes with pipda as L(1) and cbdca (1) and bpy (2) as L(2) confirms the different coordination behavior in the solid state. 相似文献
74.
Y Fujita I Mori K Ikuta Y Nakahashi K Kato T Nakanishi 《Chemical & pharmaceutical bulletin》1989,37(9):2452-2455
A highly sensitive spectrophotometric determination of human serum albumin (HSA) with 3',4',5',6'-tetrachlorogallein (T.Cl.Gall)-Mo(VI) complex in a Triton X-100 + polyvinyl alcohol micellar medium is proposed. This method can be used to determine up to ca. 150 micrograms/10 ml of HSA from the optical absorbance at 640 nm, and is superior in sensitivity to the other extremely sensitive spectrophotometric methods. The great sensitivity of this method results from the use of third-derivative spectrophotometry. The binding parameters of T.Cl.Gall-Mo(VI) complex to HSA are n = 77.3 and K = 1.05 x 10(4) M-1 as determined from dual double-reciprocal plots. It is suggested that the colored complex in this system may be the association complex between [HSA]m+ and [MoVI(T.Cl.Gall)2]n- involving hydrophobic interaction between HSA and T.Cl.Gall. The proposed method should also be useful for the detection and determination of some peptides (e.g. low molecular weight peptides containing basic amino acids), as well as proteins. 相似文献
75.
Horikiri H Hirano N Tanaka Y Oishi J Hatakeyama H Kawamura K Nagase H 《Chemical & pharmaceutical bulletin》2004,52(6):664-669
Syntheses of 10-oxo, 10alpha-hydroxy, and 10beta-hydroxy derivatives of a potent kappa-opioid receptor selective agonist, TRK-820, are described. These derivatives were supposed to be potential degradation products in formulation of TRK-820 as a result of autoxidation. 10-Oxo-TRK-820 11 was derived from 10-oxo-4,5-epoxymorphinan 14 in 10 steps in 32% overall yield. Reduction of the 10-oxo group in 4,5-epoxymorphinan with NaBH(4) gave 10beta-hydroxy-4,5-epoxymorphinan, exclusively. A stepwise inversion method of the 10beta-hydroxy group to produce 10alpha-hydroxy-4,5-epoxymorphinan was established. By HPLC analyses, 10alpha-hydroxy-TRK-820 12 was confirmed to be one of the degradation products in developing formulation of TRK-820. 相似文献
76.
Haramura M Okamachi A Tsuzuki K Yogo K Ikuta M Kozono T Takanashi H Murayama E 《Chemical & pharmaceutical bulletin》2001,49(1):40-43
Motilin antagonist was designed and synthesized on the basis of the structure-activity relationship analysis of porcine motilin that we reported recently. The drug design was performed on a specific concept to reduce a flexibility of peptide conformation of porcine motilin partial peptide by its cyclization. The cyclic peptide was synthesized using Boc (tert-butyloxycarbonyl) solid phase methodology, followed by cyclization using the azide procedure, and tested for the binding activity to motilin receptor and smooth muscle contractile activity. The cyclic peptides 3, 4, and 5 showed antagonistic property on contraction assay (pA2 [the negative logarithm of molar concentration of antagonist causing a 2-hold shift to the right of the concentration-response curve for motilin]: 4.5, 4.34, and 4.04, respectively, in rabbit duodenum) and no contractile activity even at high concentration. 相似文献
77.
The structure of a novel 3,8-seco-bicyclic taxanoid metabolite, isolated from the methanol extract of seeds of the Chinese yew, Taxus mairei, was established as (11αH)-3,8-seco-taxa-3E,7E,12(18)-triene-2α,6α,9β-triol (1) on the basis of spectral analysis including 1H NMR, 13C NMR, HMQC, HMBC, NOESY and HR-FABMS. 相似文献
78.
Takashi Hayashita Norio Teramae Toshiharu Kuboyama Shigeo Nakamura Hiromasa Yamamoto Hiroshi Nakamura 《Journal of inclusion phenomena and macrocyclic chemistry》1998,32(2-3):251-265
Recent progress in chromoionophores based on (1) spherand and hemispherand, (2) cryptand, and (3) dibenzo-16-crown-5 and calix[4]crown which selectively respond to alkali metal ions in aqueous media is reviewed in relation to their molecular structure and photometric function. The design concept of the chromoionophores for colorimetry in aqueous media is discussed in the light of their acid dissociation and metal complex formation equilibria. 相似文献
79.
Kawamura K Horikiri H Hayakawa J Seki C Yoshizawa K Umeuchi H Nagase H 《Chemical & pharmaceutical bulletin》2004,52(6):670-674
Chemical syntheses of three kinds of potential metabolites of TRK-820, a potent kappa-opioid receptor agonist, were described. One of the potential metabolites 2, 17-N-dealkylated TRK-820, was synthesized starting from noroxycodone through 8 steps in 21% total yield. Glucuronidation of intermediate 10 and compound 1, the free base of TRK-820, was carried out stereoselectively to give 3-O-beta-D-glucuronides 15 and 16 in good yields, respectively. Syntheses of potential conjugated metabolites 3 and 4 were accomplished through 10 steps and 2 steps in 11% and 43% total yields, respectively. Among the potential metabolites of TRK-820, compounds 2 and 4 were identified as metabolites in human hepatocytes. The results of pharmacological studies of compounds 2, 3, and 4 are described. 相似文献
80.
Hiromasa Goto 《Journal of polymer science. Part A, Polymer chemistry》2007,45(11):2085-2090
The electrochemically driven control of the natural optical activity of polyanilines bearing chiral camphorsulfonic acid is reported. Aniline was polymerized in the presence of camphorsulfonic acid by oxidative electrochemical polymerization in water to afford polyanilines containing (+)- or (−)-camphorsulfonic acid. This research elucidated that the polymerization, with cyclic voltammetry scanning up to 1.1 V, produced consistent optically active polyanilines. The polyaniline films thus prepared showed intense and tunable optical activity based on electrochemical reduction/oxidation in a 0.1 M sulfuric acid aqueous solution. The circular dichroism and optical rotation angle of the polymer were tunable by the appropriate adjustment of an externally applied potential as a form of optical modulation. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 2085–2090, 2007 相似文献