首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   96篇
  免费   0篇
化学   94篇
物理学   2篇
  2019年   3篇
  2017年   3篇
  2016年   3篇
  2015年   1篇
  2014年   3篇
  2013年   7篇
  2012年   7篇
  2011年   6篇
  2010年   4篇
  2009年   8篇
  2008年   6篇
  2007年   9篇
  2006年   5篇
  2005年   2篇
  2004年   7篇
  2003年   5篇
  2002年   4篇
  2001年   2篇
  2000年   3篇
  1999年   2篇
  1998年   1篇
  1997年   1篇
  1994年   1篇
  1991年   1篇
  1987年   1篇
  1983年   1篇
排序方式: 共有96条查询结果,搜索用时 250 毫秒
1.
Two isomers with empirical formula C6H6F9O9Tb are synthesized and their structures are studied. Isomerism was found to arise due to different positions of a proton. Crystals of two isomers are isostructural and form continuous series of solid solutions with C6H6F9O9Eu.  相似文献   
2.
Copper(II) compounds with the optically active diaminodioxime (H2L) derived from the monoterpenoid (+)-3-carene, Cu(H2L)(NO3)2 H2O (I), Cu(H2L)(ClO4)2 H2O (II), Cu(H2L)Br2 H2O (III), and Cu(H2L)SO40.5H2O (IV) with µeff equal to 1.81, 1.79, 1.71, and 1.8 µB, respectively, were prepared. Studies of the complexes by IR and EPR spectroscopy showed that I and II are mononuclear ionic complexes. Compound III apparently has polymeric structure (the CuN4Br2 coordination unit). According to EPR data, the Cu2+ ions in polycrystalline compounds III and IV undergo exchange interactions.Translated from Koordinatsionnaya Khimiya, Vol. 30, No. 12, 2004, pp. 897–900.Original Russian Text Copyright © 2004 by Larionov, Myachina, Sheludyakova, Boguslavskii, Tkachev, Bizyaev.  相似文献   
3.
The crystal structure of iron tris-acetylacetonate is re-determined. Crystal data at 293 K are: a = 15.4524(5) Å, b = 13.5876(4) Å, c = 16.5729(7) Å, Z = 8; at 150 K: a = 15.2541(4) Å, b = 13.4451(3) Å, c = 16.4256(5) Å, Z = 8. The structure is molecular and comprises isolated molecules. The coordination polyhderon of iron is an almost regular octahedron, Fe-O bond lengths are 1.977–2.003 Å (293 K) and 1.982–2.006 Å (150 K). In the crystalline state, the molecules are arranged in layers, and iron atoms are located on a plane yielding an almost regular trigonal net with the Fe...Fe separations of 7.558–8.103 Å (293 K) and 7.472–8.017 Å (150 K). The adjacent layer is positioned exactly over the first one with a Fe...Fe distance of 8.303 Å (293 K) and 8.236 Å (150 K).  相似文献   
4.
New optically active levorotatory compounds [Ni(HL1)]NO3 (I) and [Ni(HL2)]NO3H2O (II) containing the anions of chiral diaminodioximes, H2L1 and H2L2, derived from the terpenes ±-pinene and (+)-3-carene, respectively, were synthesized. Complexes I and II were studied by X-ray diffraction. The crystal structures of compounds are ionic, being composed of the [Ni(HL1)]+ or [Ni(HL2)]+ cations and the outer-sphere NO3 anions. The Ni2+ ion coordinates four N atoms of the tetradentate chelating ligand, the NiN4 coordination unit being shaped like a tetrahedrally distorted square. Compounds I and II are diamagnetic, which corresponds to a low-spin d8 configuration. The NMR spectra of compounds were recorded and analyzed.Translated from Koordinatsionnaya Khimiya, Vol. 30, No. 12, 2004, pp. 888–896.Original Russian Text Copyright © 2004 by Larionov, Myachina, Saveleva, Glinskaya, Klevtsova, Sheludyakova, Tkachev, Bizyaev.  相似文献   
5.
For the complexes (CH8N4)2[CuCl6], (C2H9N5)2[CuCl6] · 2H2O, and (CH8N4O)4[CuCl6]Cl4, where (CH8N4)2+, (C2H9N5)2+, and (CH8N4O)2+ are the aminoguanidinium, biguanidium, and carbohydrazidium cations, respectively, IR and Raman spectra were taken and analyzed in the region of Cu—Cl vibrations. Polarization measurements of the Raman spectra of (CH8N4O)4[CuCl6]Cl4 single crystals were performed with the purpose of assigning the vibrations to symmetry types. Vibration spectra were calculated for the hexachlorocuprate ion in the given series of compounds, and the spectra of the examined complexes were compared with spectra of the previously known compounds incorporating the hexachlorocuprate(II) ion.  相似文献   
6.
New complexes of Co(II), Ni(II), and Cu(II) with 1-(4-hydroxyphenyl)-1H-1,2,4-triazole (L) of the composition ML2(H2O)2(NO3)2 · nH2O (M = Co(II), n = 3; M = Ni(II), n = 0; M = Cu(II), n = 0) were synthesized and studied by photoelectron and IR spectroscopy, magnetochemistry, thermogravimetry, and X-ray powder diffraction analysis. The type of eff(T) relationship suggests that paramagnetic centers in the Co(II) chloride and Cu(II) nitrate and bromide complexes are involved in antiferromagnetic exchange interactions. The exchange energy values were estimated by the molecular field method.  相似文献   
7.
Russian Journal of Coordination Chemistry - Regularities of the thermolysis of acidic salts of unsaturated (maleic) [M(H2O)4(C4H3O4)2] and aromatic (ortho-phthalic) [M(H2O)6](C8H5O4)2 (M = Fe(II),...  相似文献   
8.
3-(2-Methoxyphenylamino)caran-4-one and 2-(2-methoxyphenylamino)pinan-3-one E-oximes obtained from appropriate natural terpenes were transformed into 1: 1 complexes with PdCl2. The structures of the complexes were examined by X-ray diffraction.  相似文献   
9.
Coordination compounds Pd2(H2L2)Cl4 (I), Cu2(H2L2)Cl4 (II), Pd2(H2L3)Cl4 (III), and Cu2(H2L3)Cl4 (IV), where H2L2 and H2L3 are chiral bis-α-aminooxime ligands consisting of (+)-3-carene or (+)-limonene fragments and 4,4′-methylenedianiline linker, were synthesized and examined by NMR, ESR, and IR spectroscopy. The structure of [Cu(i-PrOH)CL2(μ-H2L3)CuCL2·H2O] (V) was determined by X-ray analysis.  相似文献   
10.
The (EnH2)[AuCl4]2·2H2O (I) and (EnH2)2[AuCl4]Cl3 (II) (EnH 2 2+ is diprotonated ethylenediamine) complexes are produced and characterized by elemental and thermogravimetric analysis, X-ray diffraction, IR and Raman spectroscopy. For I, the crystals are monoclinic, crystallize in the space group P21/c: a = 7.5870(2) Å, b = 9.5665(2) Å, c = 11.4706(3) Å, β = 107.0480(10)°, V = 795.97(3) Å3, Z = 4. For II, the crystals are orthorhombic, crystallize in the space group Pnma: a = 12.7088(3) Å, b = 17.7435(5) Å, c = 7.4992(2) Å, V = 1691.06(8) Å3, Z = 8.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号