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91.
Torsten Küppers Martin Köckerling Prof. Dr. Helge Willner Prof. Dr. 《无机化学与普通化学杂志》2007,633(2):280-284
The new tetracyanoborate K[B(CN)4]·CH3CN was synthesized by dissolution of the solvent‐free K[B(CN)4] in acetonitrile and subsequent careful crystallization. The crystal structure has been determined by single‐crystal X‐ray diffraction. It crystallizes in the orthorhombic space group P212121 with Z = 4. Some comparisons with related structures are made, and the vibrational spectrum is discussed. 相似文献
92.
Crystals of Ba5Fe5−xPtxClO13 and Ba5Co5−yPtyClO13 were prepared for x=1.31, 1.51, 1.57, 1.59 and y=0, 0.97 and 1.08 in a BaCl2 flux and investigated by X-ray diffraction methods. These compounds adopt a 10H perovskite structure built from the stacking of BaO3 and BaOCl layers in the sequence (BaO3)4(BaOCl) with space group P63/mmc. The cation sites within the trimeric unit of face-sharing octahedra are occupied by Co or Fe and Pt ions, while the tetrahedral sites formed between BaO3 and BaOCl layers are only occupied by Fe or Co. Moreover, oxygen stoichiometry indicates an average oxidation state for Co and Fe higher than +III, indicating the stabilization of Co4+ and Fe4+. 相似文献
93.
The structural and magnetic properties of a new ternary Ir-Mn-Ge phase, Mn3IrGe, as well as the solid solution Mn3Ir(Si1−xGex), 0?x?1, have been investigated by means of X-ray and neutron powder diffraction, magnetization measurements and first principles calculations. The crystal structure is cubic, of the AlAu4-type (an ordered form of the β-Mn structure), Z=4, space group P213, and the unit-cell dimension varies linearly with the silicon content. For all compositions, antiferromagnetic ordering is found below a critical temperature of about 225 K. The magnetic structure is noncollinear, as a result of frustrated magnetic interactions on a triangular network of Mn atoms, on which the moments rotate 120° around the triangle axes. The magnitude of the magnetic moment at 10 K is 3.39(4) μB for Mn3IrGe. The theoretical calculations reproduce with very good accuracy the magnitudes as well as the directions of the experimentally observed magnetic moments. 相似文献
94.
Hanns‐Dieter Amberger Lixin Zhang Hauke Reddmann Christos Apostolidis Olaf Walter 《无机化学与普通化学杂志》2006,632(15):2467-2470
Electronic Structures of Organometallic Compounds of f Elements. 64 Does the Zwitterionic Nature of the Triphenylphosphine Oxide Ligand Manifest itself in its Spectrochemical Properties? The triphenylphosphine oxide mono adducts of the moiety tris(η5‐cyclopentadienyl)lanthanide(III) (Ln(Cp)3; Ln = Pr ( 1 ), La ( 2 )) were synthesized and structurally characterized. The Ln–O distances of these compounds are noticeably shorter than those of the corresponding THF adducts. A crystal field (CF) analysis of the optical spectra of 1 leads to a low absolute value of the quadratic CF parameter which is comparable with those of [Pr(Cp)3(L)]? adducts with anionic bases but not with [Pr(Cp)3(MeTHF)]. Reasons for the latter finding are presented. 相似文献
95.
在许多重要的金属蛋白中,都存在ⅡB金属与半胱氨酸残基配位的活性中心M(Cys-S)_n.锌、镉、汞与含硫配体的配位化学作为M(Cys-S)_n中心的化学基础,三配位的[M(SR)_3]被认为是金属蛋白中ⅡB金属的一种配位形式.而近年来,Koch报道了平面三配位的锌、镉、汞的硫酚配合物[(n-Pr)_4N][Zn(SC_6HMe_4-2,3,5,6)_3]和[PPh_4][Cd(SC_6H_2Pr_3~i-2,3,6)_3]及[(n-Pr)_4N][Hg(SC_6H_2Pr_3~i-2,4,6)_3]的晶体结构.他们在实验中由于晶体迅速失去溶剂而未能测定以2,4,6-三异丙基硫酚为配体的锌配合物的晶体结构.最近我们合成了这个配合物,并测定了其晶体结构. 相似文献
96.
97.
Synthesis and Crystal Structure Determination of Lead(II) Oxide Halide Alcoholates with Different Connectivity of Pb4O4 Heterocubane‐like Subunits The reaction of red lead(II) oxide (Litharge) and lead(II) halide (Cl? and Br?) with diethylene glycole at a temperature of 180 °C leads to the isotypic compounds [Pb6(C4H8O3)O2Cl6] (1) and [Pb6(C4H8O3)O2Br6] (2) . In a similar synthesis with PbI2 as educt at temperature of 160 °C the two modifications β‐[Pb6(C4H8O3)O2I6] (3) and α‐[Pb6(C4H8O3)O2I6] (4) were found, whereas at a reaction temperature of 180 °C [Pb9(C2H4O2)(C4H8O3)O3I8] (5) was surprisingly obtained as product. The X‐ray diffraction data show that at a temperature of 180 °C a splitting of the ether took place. The cited compounds show cubane like subunits built by lead and oxygen atoms. These fragments are connected by alkoholate molecules. In 5 additionally an I6 octahedra centered by lead is observed. 相似文献
98.
One novel complex [Co(p-MBA)2(2,2'-bipy)(H2O)]·(H2O) has been synthesized by the reaction of p-methylbenzoic acid with 2,2'-bipyridine in the solvent mixture of water and methanol. It crystallizes in triclinic, space group P-1 with a=0.70479(14), b=1.1211(2), c=1.6718(3) nm, α=103.806(3), β=90.795(3), γ=104.207(3)°, V=1.2399(4) nm3, Mr=512.41, Dc=1.373 g/cm3, Z=2, F(000)=532, μ=0.733 mm-1, R=0.0432 and wR=0.0957. The crystal structural analysis shows that the cobalt atom is coordinated with three oxygen atoms from two p-methylbenzoic acids and one water molecule and two nitrogen atoms from one 2,2'-bipyridine,forming a distorted square-pyramidal coordination geometry. The cyclic voltammetry behavior of the complex is also reported. 相似文献
99.
研究了4-位苯基取代基旋转受阻和旋转自由的2,4,6-三苯基氧盐的光物理性质。实验结果表明,当4-位苯基取代基旋转受阻时,氧盐化合物在激发态时引起的分子内极化程度比4-位取代基旋转自由的氧盐化合物大,即在激发态时旋转受阻氧盐化合物发生的分子内电荷转移能力较强;4-位取代基旋转自由的化合物的荧光量子产率随溶剂粘度的增大而有所增大,但旋转受阻化合物在相同的条件下则出现相反的结果。实验结果还表明,4-位取代苯基旋转受阻对化合物的荧光发射不利。 相似文献
100.
从(-)-(1S,2R,4S)-5,6-二亚甲基双环[2.2.1]庚-2-醇(I)和(-)-(1S,2S,4S)-5,6-二亚甲基双环[2.2.1]庚-2-醇(Ⅱ)出发,合成了它们的醚类和取代苯甲酸酯类光学纯的衍生物。通过[α]D测定和构型分析,发现它们是含有3个手性碳(C1,C2和C4)的桥环化合物,其旋光性与构型的关系均符合可极化度多级圆球不对称性模型。 相似文献