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111.
Eight benzotriazoles and (4-methoxy)benzotriazoles, mono- or di-substituted derivatives of 2,4-dihydroxyaceto(or benzo)phenone were synthesized by azo coupling of (4-methoxy)2-nitrobenzenediazonium chloride with 2,4-dihydroxyaceto(or benzo)phenone followed by reductive cyclization. Pure mono-substituted compounds were very difficult to prepare. Careful selection of thepH for the azo coupling and selection of the proper reagents for the reductive cyclization were essential. All compounds were characterized by their ultraviolet, infrared1H and13C NMR spectra and their elemental analysis. These compounds have both the 2(2-hydroxyphenyl)2H-benzotriazole unit and a 2-hydroxyaceto(or benzo)phenone unit in the same molecule and are effective and useful ultraviolet absorbers.Dedicated to Prof. Dr.K. Komarek, Vienna, on the occasion of his 60th birthday with best wishes. 相似文献
112.
Tatsuro Ouchi Hirotoshi Fujie Satoshi Jokei Yoshiomi Sakamoto Hidenori Chikashita Takeshi Inoi Otto Vogl 《Journal of polymer science. Part A, Polymer chemistry》1986,24(9):2059-2074
Acryloyl-type polymer fixing 1-β-carbonylethyl-5-fluorouracil residues through D -glucofuranoses via ester bonds was synthesized by means of polymerization of the corresponding monomer and polymer reaction. In order to provide the water-soluble objective polymer, the copolymerization of the acryloyl-type monomer with acrylamide was carried out. The extent of release of 5-FU residues from the copolymer was investigated in the enzyme or nonenzyme system in vitro. Furthermore, the antitumor activities of the water-insoluble homopolymer and water-soluble copolymer obtained were tested in vivo. 相似文献
113.
Pilar Jiménez Maria Victoria Roux JiŘi Kulhánek Otto Exner 《Structural chemistry》1996,7(5-6):375-381
The energy of combustion of 2,5-dimethoxybenzoic acid has been determined using a static bomb calorimeter. The vapor pressures of the compound have been measured over a 18 K temperature interval by the Knudsen effusion technique. Heat capacity measurements betweenT=270 K andT=338 K were carried out by DSC. From these experimental results the standard molar enthalpies of combustion, sublimation, and formation in the crystalline and gaseous state at the temperature 298.15 K have been derived. With this compound, the series of mono- and dimethoxy-benzoic acids have been completed. Theirf H
m
o
values were expressed by an additive relationship, taking into account the number of methoxy groups and the number of all 1,2 interactions: an accuracy of 3.3 kJ·mol–1 was achieved. In an alternative approach the substituent effect of the methoxy groups was evaluated within the framework of isodesmic reactions. The effect of disubstitution was referred to mono derivatives and the excess energy—the so-called buttressing effect—was evaluated (2–24 kJ· mol–1 for individual bis derivatives). These values were explained in terms of the conformation of the methoxy group around the Car-O bond. 相似文献
114.
Otto Vogl Jan Bartus Joseph R. Murdoch 《Monatshefte für Chemie / Chemical Monthly》1990,121(4):311-316
Summary We report techniques for measuring optical rotation of suspended solids, including dissymmetric molecular crystals (e.g. sodium chlorate and bromate), synthetic polymers, polypeptides and biopolymers. Examples include poly(triphenylmethyl methacrylate), poly-S-lactide, poly-L-hydroxyproline, hemocyanine, cellulose acetate andRNA. The results indicate that optical rotation measurements are sensitive to differences in secondary structure and can serve as a probe for structural differences between solid-state and solution.
Messung der optischen Rotation von Makromolekülen im Festzustand unter Verwendung von Pulversuspensionen
Zusammenfassung Es wird über eine Methode zur Messung der optischen Rotation von Festkörpern in Suspensionen berichtet, wobei dissymetrische Kristalle (z. B. Natriumchlorat und -bromat), synthetische Polymere, Polypeptide und Biopolymere behandelt werden. Die Beispiele umfassen Poly(triphenylmethylmethacrylat), Poly-S-lactid, Poly-L-hydroxyprolin, Hemocyanin, Celluloseacetat undRNA. Die Ergebnisse zeigen, daß die optischen Rotationen bezüglich Unterschiede in der Sekundärstruktur empfindlich sind und daß diese Messungen als ein Maß für Strukturunterschiede zwischen Festzustand und Lösung herangezogen werden können.相似文献
115.
M. Sc. Benjamin Scheibe Clemens Pietzonka M. Sc. Otto Mustonen Prof. Dr. Maarit Karppinen Prof. Dr. Antti J. Karttunen Prof. Dr. Mihail Atanasov Prof. Dr. Frank Neese Dr. Matthias Conrad Prof. Dr. Florian Kraus 《Angewandte Chemie (International ed. in English)》2018,57(11):2914-2918
The D2h‐symmetric dinuclear complex anion [U2F12]2? of pastel green Sr[U2F12] shows a hitherto unknown structural feature: The coordination polyhedra around the U atoms are edge‐linked monocapped trigonal prisms, the UV atoms are therefore seven‐coordinated. This leads to a U–U distance of 3.8913(6) Å. A weak UV–UV interaction is observed for the dinuclear [U2F12]2? complex and described by the antiferromagnetic exchange Jexp of circa ?29.9 cm?1. The crystalline compound can be easily prepared from SrF2 and β‐UF5 in anhydrous hydrogen fluoride (aHF) at room temperature. It was studied by means of single crystal X‐ray diffraction, IR, Raman and UV/VIS spectroscopy, magnetic measurements, and by molecular as well as by solid‐state quantum chemical calculations. 相似文献
116.
Otto M 《Fresenius' Journal of Analytical Chemistry》2001,369(7-8):738-740
The present situation of analytical chemistry teaching within a chemistry curriculum is exemplified by the reformed chemistry curriculum in Germany. This approach is contrasted with teaching analytical chemistry within a novel curriculum in natural sciences termed 'applied science'. The latter curriculum ensures a superior education in chemistry, physics, biology, mathematics and information science, thus gaining an integrated perspective of analytical chemistry. 相似文献
117.
Two different human mammary carcinoma cell lines were xenotransplanted into nude mice. Serum samples were obtained prior to and after transplantation and investigated by two-dimensional electrophoresis (2-DE). By comparison of these silver-stained patterns additional protein spots were detected resulting either from proteins secreted or shed by the tumor itself or from mouse proteins induced by the tumor or the transplantation procedure. One group of spots detectable in post-transplantation serum as well as in control serum after mock-transplantation but not in pretransplantation serum was microsequenced and identified as mouse beta-haptoglobin. The carbohydrate structures of beta-haptoglobin were characterized by two different immunochemical glycoprotein staining procedures to detect differential terminal glycan modifications. 相似文献
118.
Eichhorn C Scherer OJ Sögding T Wolmershäuser G 《Angewandte Chemie (International ed. in English)》2001,40(15):2859-2861
119.
M. Otto 《Analytical and bioanalytical chemistry》2001,369(7-8):738-740
The present situation of analytical chemistry teaching within a chemistry curriculum is exemplified by the reformed chemistry curriculum in Germany. This approach is contrasted with teaching analytical chemistry within a novel curriculum in natural sciences termed ‘applied science’. The latter curriculum ensures a superior education in chemistry, physics, biology, mathematics and information science, thus gaining an integrated perspective of analytical chemistry. 相似文献
120.