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61.
A series of novel two-dimensional (2D) and three-dimensional (3D) praseodymium coordination polymers, namely, {[Pr3(PDA)4(HPDA)(H2O)8] x 8H2O}n (2), {[Pr2(PDA)3(H2O)3] x H2O}n (3), {[Pr(PDA)(H2O)4] x ClO4}n (4), and { [Pr2(PDA)2(H2O)5SO4] x 2H2O}n (5) (PDA = pyridine-2,6-dicarboxylic anion), was designed and synthesized under hydrothermal conditions. Complexes 1-3 (chainlike polymer, {[Pr(PDA)(HPDA)(H2O)2] x 4H2O}n (1) was also obtained independently by us, although it has been reported recently by Ghosh et al.) were fabricated successfully by simply tuning the Pr/PDA ratio and exhibited various and intriguing topological structures from a 1D chain to a 3D network. While the synthetic strategy of 5 was triggered and further performed only after 1 was structurally characterized. The complexes were characterized by X-ray single-crystal determination, spectroscopic, and variable-temperature magnetic susceptibility analyses. In complex 2 an unusual nanosized square motif as a building block constructed by eight Pr ions was further assembled into a highly ordered 2D grid compound. In complex 3 the decanuclear Pr metal-based structure as a repeat unit interpenetrated to form a novel 3D polymer. Complex 4 was a 3D network polymer fabricated through a hexanuclear Pr ring as a building block, and ClO4- anions as guests were trapped in the cavity. In complex 5 six Pr atoms, two SO4(2-) anions, and carboxylic oxygen bridges constructed an intriguing rectangle structure as a repeat unit in the grid to form a 2D coordination polymer in which the unique bi-bidentate coordination mode of SO4(2-) anion was observed. 相似文献
62.
Jie Chen Rong Ji Dai Bin Tong Sheng Yuan Xiao Wei Wei Meng 《中国化学快报》2007,18(1):10-12
The reduction of 4-nitrophenol catalyzed by nitroreductase in the presence of NADH was investigated in this paper.4-Amino- phenol and 4-bydroxylamino-phenol were found in the reductive products.The relationship between reaction time and the reductive ratio were studied.The similar reducing ratios of 4-nitrophenol were obtained under aerobic and anaerobic conditions.The results indicated that an oxygen-insensitive reaction was proceeded in the reduction of 4-nitrophenol and nitroreductase was an oxygen- insensitive enzyme.The reductive products of 4-nitrophenol were determined by HPLC and MS. 相似文献
63.
Growth of porous single-crystal Cr2O3 in a 3-D mesopore system 总被引:1,自引:0,他引:1
Jiao K Zhang B Yue B Ren Y Liu S Yan S Dickinson C Zhou W He H 《Chemical communications (Cambridge, England)》2005,(45):5618-5620
Single-crystal Cr2O3 with regular mesopores has been synthesized using mesoporous silica KIT-6 as a template and characterized by using XRD, HRTEM and nitrogen adsorption/desorption. 相似文献
64.
We report herein an efficient catalytic epoxidation reaction for the synthesis of epoxyketone (tert-butyl ((S)-4-methyl-1-((R)-2-methyloxiran-2-yl)-1-oxopentan-2-yl)carbamate), which is an important synthetic intermediate of carfilzomib. 相似文献
65.
Tee Lee Theng Zaharuddin Ahmad Che Abd Rahim Mohamed 《Journal of Radioanalytical and Nuclear Chemistry》2004,262(2):485-488
Polonium-210 has been measured in the soft parts of Anadara granosa purchased at Kuala Selangor, West Coast of Malaysia in August 2001, April 2002 and September 2002. It is shown that 210Po is non-uniformly distributed within cockles of various sizes (i.e., 2.5, 3.0, 3.5 and 4.0 cm of shell length) and the concentration
of 210Po in the soft parts of cockle was significantly different (p<0.05) due to sampling date. The highest value was observed in the smallest cockle with a shell length of 2.5 cm (411.6±26.16
Bq/g dry wt.). It is clear that there is an allometric relationship between 210Po activity concentration and individual cockle weight. This may reflect on the differences of metabolic rate and growth age
of cockles. The mean activity concentration of 210Po measured in Kuala Selangor filtered water were 1.75±0.17, 0.79±0.08 and 1.13±0.20 Bq/kg for August 2001, April 2002 and
September 2002, respectively. The yield concentration factors for 210Po in the soft parts of cockles varies from 27.3. 103 to 106.9. 103.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
66.
合成了导电性TCNQ盐Cu(pn)2(TCNQ)n(n=2和3,pn=1,2-丙二胺,TCNQ=7,7,8,8-四氰基对苯二醌二甲烷)。红外光谱、电子光谱和X-光电子能谱研究表明TCNQ盐中存在TCNQ°和TCNQ-,TCNQ°与TCNQ-之间发生了部分电子转移,致使铜呈混合价态。它们的粉末室温电导率为1.1×10-5~2.4×10-6ohm-1cm-1。 相似文献
67.
Dispersion of MoO3, NiO, ZnO on rutile TiO2 with low specific surface area was studied with Mercury Porosimeter, SEM, XPS and Ammonia Extraction method. The dispersion thresholds of MoO3, NiO, ZnO on three rutile TiO2 carriers were obtained with XPS, and com-pared with those on anatase TiO2 with high specific surf are area. Ammonia Extraction method was used to identify the surface oxide species interarting with support surface in different strength and it was found that the proportions of oxides that can not be extracted by ammonia extraction are different for MoO3, NiO and ZnO which are supported on rutile TiO2. 相似文献
68.
Kayed A. Abu Safieh Ahmad M. Abu Mahthieh Mustafa M. El-Abadelah Mikdad T. Ayoub Wolfgang Voelter 《Monatshefte für Chemie / Chemical Monthly》2007,21(9):157-160
A novel method for the synthesis of a new series of 5-substituted 1,3-dimethyl pyrazolo[4,3-e][1,2,4]triazines is described. The new synthetic strategy is based on the classical Bischler 1,2,4-benzotriazine synthesis. This approach involves the preparation of 5-hydrazinopyrazole from 5-chloro-1,3-dimethyl-4-nitropyrazole
followed by acylation and nitro group reduction to form the corresponding 4-amino-3-(acylhydrazino)pyrazoles. Intramolecular
oxidative cyclization of the latter derivatives, using polyphosphoric acid, produced the respective target pyrazolotriazines. 相似文献
69.
Discharge performance of K2FeO4 electrode under different conditions was studied by the constant electric current discharge method. The electrochemical characteristics of K2FeO4 electrode were investigated for the first time by means of cyclic voltammetry. The results show that the K2FeO4 electrode made at moderate pressure (20MPa) and discharged at lower current has better discharge performance. It is also found that K2FeO4 electrode is significantly rechargeable. 相似文献
70.