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971.
With the B3LYP calculation method of density functional theory(DFT)and the 6-31G* basis set,full optimization calculation was made for phenoxathiin10-oxide(PTO)and 135 polybromine phenoxathiin 10-oxides(PBPTOs)with the Gaussian 03 program and molar heat capacity in constant volume(CVθ)value of each molecule in the standard state was obtained.The relation between CVθ and the substitution position and number of bromine atom(NPBS)was studied,and the results indicated good correlation(R2 = 1.000)between CVθ and NPBS of PBPTO compounds.Based on the output file of Gaussian 03 program,molar heat capacity at constant pressure(Cp,m)of PBPTO compounds from 200 to 1,000 K was calculated with the statistical thermodynamics program,and the correlation equation between Cp,m and temperature(T,T-1 and T-2)was obtained with the least-squares method,and the correlation coefficient of the correlation equation(R2)was 1.000.In addition,based on the partition function of each molecule calculated by vibration analysis,the relative rate constant of formation of each molecule was calculated. 相似文献
972.
Antimony distribution and mobility in rivers around the world's largest antimony mine of Xikuangshan, Hunan Province, China 总被引:6,自引:0,他引:6
Mining and smelting activities of the world largest Antimony (Sb) mine which is located at Xikuangshan area of Hunan Province, China, constitute important sources of Sb pollution throughout the rivers in or around the mine. Water samples show high levels of Sb (2-6384 µg/l) relative to the average concentration of the world rivers (1 µg/l) and it occurs mainly in oxidized form. Sb has a higher affinity for the particulate phase than for the aqueous phase. Its contents in sediments decreased along with the distance from the mine (from 7316 to 57 mg/kg) and had good correlation relationships (p < 0.001) with porewaters. In addition to the major pools in the Fe-Mn oxide (22.2-66.4%) and residual fractions (5.66-53.5%), Sb was relatively abundant in strongly adsorbed fraction. Laboratory experiments of the contaminated sediments show that with increasing amounts of Sb in the sediment, an increasing amount of Sb was leached and went into solution. Although Sb(V) was the predominant form, the release of Sb(III) in oxic conditions was also observed during laboratory experiments. And the amount of Sb released into solution was higher in anaerobic conditions than in oxygenated water. 相似文献
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978.
5,10,15,20—四(对—乙酯苯基)卟啉LB膜的结构 总被引:1,自引:0,他引:1
对卟啉类化合物LB膜的结构、电性质和气敏性的研究已见报道。本文利用膜天平和UV-Vis分光光度计研究了标题化合物在气-液界面上的成膜特性、分子间相互作用和LB膜的结构。5,10,15,20-四(对-乙酯苯基)卟啉(TPEPP)由5,10,15,20-四(对-氰苯基)卟啉和乙醇酯化得到。元素分析测定值与计算值相符。λ(CHCl_3,nm):421,515,550,590,645;ν(KBr压 相似文献
979.
Two mononuclear metal-organic complexes, [Co(Hmpdc)2(H2O)4]·4H2O 1 and [Ni(Hfmpdc)2(H2O)4]·6H2O 2, were prepared from 2,6-dimethylpyridine-3,5-dicarboxylic acid (Hzmpdc) and 4-furyl-2,6-dimethylpyridine-3,5-dicarboxylic acid (H2fmpdc) with M(NO3)2 salts, respectively, and characterized by single-crystal X-ray diffraction, elemental analyses, IR spectroscopy, and photoluminescent measurement. Complex 1 crystallizes in triclinic, space group P1 with a = 7.634(5), b = 8.695(5), c = 10.757(6)A, α = 69.647(7), β = 69.957(8), γ = 83.733(7)°, V = 628.9(7)A^3, Dc = 1. 561 g/cm^3,μ(MoKa) = 0.763 mm^-1, F(000) = 309, Z = 1, the final R = 0.0553 and wR = 0.1469 for 1909 observed reflections (Ⅰ 〉 2σ(Ⅰ)). Complex 2 crystallizes in monoclinic, space group P21/n with a = 9.5934(16), b = 12.422(2), c = 14.826(3) A, β = 105.201(2)°, V = 1705.0(5)A3, Dc = 1. 479 g/cm^3,μ(MoKa) = 0.655 mm^-1, F(000) = 796, Z = 2, the final R= 0.0351 and wR = 0.0889 for 2387 obsevved reflections (Ⅰ 〉 2σ(Ⅰ)). In the crystal structures of 1 and 2, diverse supramolecular motifs from 1-D chains/ladders to 3-D networks are constructed from corresponding distinct [M^Ⅱ(H2O)8] ion clusters as the second building units, respectively. The solid state compounds of 1 and 2 show similar photoluminescent spectra with emission maximum at ca. 相似文献
980.
通过水热方法合成了一种新颖的异金属金属-异烟酸无机-有机杂化体[Zn0.5(H2O)]{(Hg2Cl5)[Er(C6NO2H4)3(H2O)2]}(HgCl2)·0.5CH3OH·0.5H2O (1)并对其进行了单晶X-射线衍射结构表征。该化合物是首例4f-3d-5d多金属-异烟酸配合物。化合物1属于单斜晶系C2/c空间群,每个单胞中有8个分子,晶体学参数为:a = 34.165(4) Å,b = 9.4692(8) Å,c = 24.575(3) Å,β = 115.090(5)°,V = 7200(1) Å3,C18.50H21Cl7ErHg3N3O10Zn0.50,Mr = 1495.25,Dc = 2.759 g/cm3,T = 293(2) K,μ(MoKα) = 15.954 mm-1,F(000) = 5400, R1/wR2 = 0.0561/0.0909,共有6468个独立衍射点,其中[I > 2σ(I)]的有3157个。该化合物具有新颖的二维{(Hg2Cl5)[Er(C6NO2H4)3(H2O)2]}层状结构,由Hg2Cl5–连接[Er(C6NO2H4)3(H2O)2]链形成。该二维层和氯化汞及结晶水之间通过氢键形成三维结构,甲醇分子和水合锌离子位于该三维结构的空隙中。对化合物1的磁性测试显示该化合物具有反铁磁作用。 相似文献