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71.
Anwar Usman Suchada Chantrapromma Hoong‐Kun Fun Bo‐Long Poh Chatchanok Karalai 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(3):o136-o138
In the title 1/2/2 adduct, C4H12N22+·2C6H3N2O5?·2H2O, the dication lies on a crystallographic inversion centre and the asymmetric unit also has one anion and one water molecule in general positions. The 2,4‐dinitrophenolate anions and the water molecules are linked by two O—H?O and two C—H?O hydrogen bonds to form molecular ribbons, which extend along the b direction. The piperazine dication acts as a donor for bifurcated N—H?O hydrogen bonds with the phenolate O atom and with the O atom of the o‐nitro group. Six symmetry‐related molecular ribbons are linked to a piperazine dication by N—H?O and C—H?O hydrogen bonds. 相似文献
72.
YANG Jia-Xianga ZHANG Zeb WU Jie-Yinga TIAN Yu-Penga c② DU Pengb LIU Qing-Liangb FUN Hoong Kund C. Suchadad a 《结构化学》2003,22(5):558-562
1 INTRODUCTION During the search of molecule-based materials with interesting properties such as catalysis, cla- thration etc., much attention has been focused on the synthesis of one-, two- and three-dimensional extended solids involving cadmium[1], as its d10 configuration permits a wide variety of geometries and coordination numbers. Rigid bridged ligands such as carboxylate groups are frequently used to construct these materials. Therefore, the coordi- nation chemistry of Cd(Ⅱ) ca… 相似文献
73.
A low temperature method, in which the progress of the oxidation of secondary diarylamines with DMDO at low temperatures is monitored by magnetic resonance spectroscopy (EPR and NMR) and magnetic studies by a Superconducting Quantum Interference Device (SQUID), is developed for preparation of the first m-phenylene based diarylnitroxide diradical. EPR spectroscopy and magnetic studies (SQUID) indicate that the diradical in the dichloromethane matrix predominantly adopts anticonformation ( 2A-anti) and possesses triplet ground state. Similar oxidation experiments for conformationally constrained aza[1 4]metacyclophane provide evidence for the formation of small amounts of the corresponding diarylnitroxide diradical. Both diarylnitroxide diradicals could only be detected at low temperatures (-80 degrees C and below). 相似文献
74.
Ying‐Hong Lu Hoong‐Kun Fun Suchada Chantrapromma Ibrahim Abdul Razak Zhen Shen Jing‐Lin Zuo Xiao‐Zeng You 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(8):911-913
The title dinuclear di‐μ‐oxo‐bis[(1,4,8,11‐tetraazacyclotetradecane‐κ4N)manganese(III,IV)] diperchlorate nitrate complex, [Mn2O2(C10H24N4)2](ClO4)2(NO3) or [(cyclam)MnO]2(ClO4)2(NO3), was self‐assembled by the reaction of Mn2+ with 1,4,8,11‐tetraazacyclotetradecane in aqueous media. The structure of this compound consists of a centrosymmetric binuclear [(cyclam)MnO]3+ unit, two perchlorate anions and one nitrate anion. While the low‐temperature electron paramagnetic resonance spectra show a typical 16‐line signal for a di‐μ‐oxo MnIII/MnIV dimer, the magnetic susceptibility studies also confirm a characteristic antiferromagnetic coupling between the electronic spins of the MnIV and MnIII ions. 相似文献
75.
Nawong Boonnak Chatchanok Karalai Suchada Chantrapromma Hoong-Kun Fun Kan Chantrapromma 《Tetrahedron》2009,65(15):3003-3013
Cochinchinones I-L (1-3 and 13) along with 11 known xanthones (4-12, 14, and 15) were isolated from the resin and green fruits of Cratoxylum cochinchinense. In addition, four new acetylated compounds (16-19) were derivatized from 7-geranyloxy-1,3-dihydroxyxanthone (14) and 3-geranyloxy-1,7-dihydroxyxanthone (15). All compounds were characterized on the basis of spectroscopic analyses. The structures of cochinchinone I (1), a monoacetate (18) and a dibrosylate (20), were also confirmed by X-ray diffraction analysis. The antibacterial and antifungal activities of selected compounds were evaluated as well. 相似文献
76.
Suchada Chantrapromma Ibrahim Abdul Razak Hoong-Kun Fun Chatchanok Karalai Hao Zhang Fu-Xin Xie Yu-Peng Tian Wen Ma Yin-Han Zhang Shi-Sheng Ni 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(3):289-290
The title compound, a novel 30-membered 2:2 macrocyclic thiocarbohydrazone, C34H32N8O4S2·3C5H5N, has been prepared and crystallographically characterized. The molecule of the compound is twisted. One dioxabutane group is boat-like in shape, whereas the other is highly disordered. The crystal structure is stabilized by inter- and intramolecular hydrogen bonds. 相似文献
77.
Passapol Ngamukot Thiraporn Charoenraks Orawon Chailapakul Shoji Motomizu Suchada Chuanuwatanakul 《Analytical sciences》2006,22(1):111-116
An electrooxidation and a cost-effective flow-based analysis of malachite green (MG) and leucomalachite green (LMG) were investigated at a boron-doped diamond thin-film (BDD) electrode. Cyclic voltammetry as a function of the pH of the supporting electrolyte solution was studied. Comparison experiments were performed with a glassy carbon electrode. A well-defined cyclic voltammogram, providing the highest peak current, was obtained when using phosphate buffer at pH 2. The potential sweep-rate dependence of MG and LMG oxidation (peak currents for 1 mM MG and LMG linearly proportional to v 1/2, within the range of 0.01 to 0.3 V/s) indicates that the oxidation current is a diffusion-controlled process on the BDD surface. In addition, hydrodynamic voltammetry and amperometric detection using the BDD electrode combined with a flow injection analysis system was also studied. A homemade flow cell was used, and the results were compared with a commercial flow cell. A detection potential of 0.85 V was selected when using a commercial flow cell, at which MG and LMG exhibited the highest signal-to-background ratios. For the homemade flow cell, a detection potential of 1.1 V was chosen because MG and LMG exhibited a steady response. The flow analysis results showed linear concentration ranges of 1-100 microM and 4-80 microM for MG and LMG, respectively. The detection limit for both compounds was 50 nM. 相似文献
78.
Seik Weng Ng Suchada Chantrapromma Ibrahim Abdul Razak Hoong-Kun Fun 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(3):291-292
The triclinic cell of the title compound contains 2C12H24N+·2C6H5O2S− ion pairs that are linked by four hydrogen bonds [N⃛O = 2.728 (3) and 2.758 (3) Å] across a centre of inversion. 相似文献
79.
Anwar Usman Ibrahim Abdul Razak Suchada Chantrapromma Hoong‐Kun Fun Tarun K. Sarkar Sankar Basak Gur Dayal Nigam 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(9):1116-1117
In the title compound, C16H19ClN2O4, the pyridine ring is nearly planar, the piperidine ring is non‐planar and the cyclohexane ring adopts a screw‐boat conformation. The carboxylate group makes a dihedral angle of 80.9 (2)° with the least‐squares plane through the cyclohexane ring. 相似文献
80.
Suchada Chanprateep Ketsunee Buasri Aumtiga Muangwong Phonpisit Utiswannakul 《Polymer Degradation and Stability》2010,95(10):2003-2012
Poly(3-hydroxybutyrate), PHB, and poly(3-hydroxybutyrate-co-4-hydroxybutyrate), P(3HB-co-4HB), consisting of 0-94% mole fraction of 4HB content, were produced in high content by Cupriavidus necator strain A-04. The carbon sources used for PHB production included sugars made locally in Thailand: refined sugarcane, brown sugarcane, rock sugar, toddy palm sugar and coconut palm sugar. The switching of the ratios of carbon to nitrogen, together with the ratios of fructose to 1,4-butanediol, were applied to P(3HB-co-4HB) production in fed-batch cultures. Optimal P(3HB-co-4HB) production was achieved with 112 g biomass and 73 g P(3HB-co-4HB) with 38% mole fraction of 4HB content. Next, P(3HB-co-4HB) with a 0, 5, 24, 38 and 64% mole fraction of 4HB content were purified and prepared as plastic films. The mechanical properties and biocompatibility of these films were tested and compared with commercial PHB, polystyrene (PS) and polyvinylchloride (PVC) prepared without additives. The results demonstrated that PHB had thermal and mechanical properties similar to those of commercial PHB. The P(3HB-co-4HB) polymers possessed melting temperature and glass transition temperature values higher than those reported previously. The mechanical properties were compared with those of PS and PVC. The in vitro biocompatibility was assessed using L929, human dermal fibroblast and Saos-2 human osteosarcoma cells. The cytotoxicity results and scanning electron micrographs showed that P(3HB-co-4HB) films have good surface characteristics and can promote cell attachment, proliferation and differentiation. Combined with their good mechanical properties, P(3HB-co-4HB) polymers possess potential usefulness for biomaterial applications in artificial skin tissue support and orthopedic support. 相似文献