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951.
Liang Oyang Hao-Ling Sun Xin-Yi Wang Jun-Ran Li Dao-Bo Nie Wen-Fu Fu Song Gao Kai-Bei Yu 《Journal of Molecular Structure》2005,740(1-3):175-180
Ternary terbium complexes with p-aminobenzoic acid (HL), [TbL3(DMSO)(H2O)]2 (1), [TbL3(DMF)(H2O)]2 (2) and [TbL3(Bpy)(H2O)]2·2H2O (3) (DMSO=dimethyl sulfoxide, DMF=N, N- dimethylformamide, Bpy=2, 2′- bipyridyl) have been synthesized, and their crystal structures determined. The luminescence properties of these complexes, including both the emission quantum yield and the fluorescence lifetime, have been investigated. The effect of a second ligand on the crystal structure and luminescence property of the ternary terbium p-aminobenzoic acid complexes, and the relationship between luminescence properties and crystal structure, including coordination mode of the L− ligand and the characteristics of a second ligand, are discussed. 相似文献
952.
1 INTRODUCTION Coordination chemistry has been playing an important role in nonlinear optical (NLO) materi- als [1~3] in recent years. It has been found that tetrahedral or square pyramidal molecular configurations are useful for designing transparent second-harmonic generation (SHG) materials from coordination compounds[4]. It has also been reported that the pyridyl-based metal complexes can exhibit SHG effects[5]. Recently, we have successfully synthesized a new coordination compoun… 相似文献
953.
J. Lédé 《Journal of Thermal Analysis and Calorimetry》1996,46(1):67-84
This paper deals with models describing the thermal and chemical behaviour of solid particles undergoing fast endothermic reactions under the influence of an external heat flux. The heat source temperature is supposed to be constant, to increase with time, or to deliver a simple thermal flash. It is shown that the pyrolysis conditions (reaction temperature, conversion, etc.) depend on the chemical characteristics of the reaction and also to a large extent on the external heating conditions. Relationships are proposed to take into account these parameters. The results are applied to the thermal decomposition of NaHCO3. The pyrolysis of cellulose is finally chosen in order to show how these operating parameters can also affect the selectivity of a more complex reaction. 相似文献
954.
类立方烷型金属原子簇化合物M_4E_4(M为过渡金属,E为硫属元素)的研究长期以来受到重视,其主要原因有二:(1)一些类立方烷型金属原子簇(如Fe_4S_4及Fe-Mo-S原子簇)在生物体系(如固氮酶、铁氧还蛋白)中有重要意义;(2)由于可以方便地对M或E作系列性的改变,因而M_4E_4成为研究原子簇化合物的电子结构及检测各种有关的理论假设的重要模型化合物。 相似文献
955.
Guang-Ming Yang Peng Cheng Dai-Zheng Liao Zong-Hui Jiang Shi-Ping Yan Geng-Lin Wang Xin-Kan Yao Hong-Gen Wang 《Journal of Cluster Science》1998,9(4):465-471
The preparation, magnetic properties, and crystal structure of [(salen)Cu]4[(salen)Fe(H2O)2]2(ClO4)2 via hydrogen bonding are described [salen=N,N-ethylenebis (salicylideneiminate)]. Crystals are triclinic, of space group
, with cell constants a=12.853(3), b=13.921(3), c=14.251(3) Å, =68.68(3)°, =87.86(3)°, =86.82(3)°, and Z=1. The structure was solved and refined to R=0.064 and R=0.068. The structure comprises the hexanuclear units which result from the linking of four mononuclear fragments [(salen)Cu] and two mononuclear fragment [(salen)Fe(H2O)]+, through Cu -O H -O -Fe -O -H O -Cu hydrogen bonds of coordinating H2O. In this complex, FeIII ions are in almost square-planar surroundings. The temperature dependences of the magnetic susceptibilities of the complex have been studied in the 4.2–300 K range, indicating the presence of an antiferromagnetic interactions between metal ions. 相似文献
956.
For the first time the isomerization of 1,3,2-diazaphospholidine-2-sclenide dervatives in refluxing benzene in the presence of trace water was observed. The structures of isomerized products were determined by IR, ^1H NMR,^31P NMR, elemental analysis and X-ray crystallography. The mechanism of isomerization was also proposed. 相似文献
957.
958.
A. Amengual 《Journal of Thermal Analysis and Calorimetry》1994,41(6):1557-1569
The development of a temperature control system based on semiconductor thermobatteries has been used in a set of devices for studying the martensitic transformation. The devices range from a simple stage for an optical microscope to a more elaborated system as a differential scanning calorimeter [1]. Here the attention is placed in this last system. The general problems of the temperature scanning calorimetry are reviewed from the signal theory point of view and the solutions applied to our system discussed. Some measurements are shown as an example of its application. 相似文献
959.
两种结构钼磷酸的催化氧化行为 总被引:11,自引:0,他引:11
考察了Dawson与Keggin结构钼磷酸的催化氧化行为,并与结构特性进行了关联,结果发现,Dawson结构的杂多酸对氧化脱氢及插入氧反应均有更高的活性。 相似文献
960.
D. N. Dybtsev I. E. Sokolov E. V. Peresypkina V. P. Fedin 《Russian Chemical Bulletin》2007,56(2):225-230
Two new scaffold-like metal-organic coordination polymers, [Zn2ndc2bpe]·DMF and [Zn2ndc2dedpbp] ·4DMF (ndc is 2,6-naphthalenedicarboxylate, bpe is trans-bis(4-pyridyl)ethylene, and dedpbp is 4,4′-diethynyl-4″,4′″-dipyridylbiphenyl), were synthesized by heating stoichiometric
amounts of zinc(II) nitrate, H2ndc, and bpe or dedpbp in DMF. The structures of the polymers were established by X-ray diffraction. Coordination of linear
dicarboxylate ligands to zinc cations gives rise to planar square-grid networks, and additional coordination of the bifunctional
nitrogen-containing ligands results in the formation of scaffold-like triply interpenetrating structures with a primitive
cubic topology.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 219–223, February, 2007. 相似文献