Inclusion complexes of the natural product gossypol. Recognition by gossypol of halogeno methanes. Structure of the dichloromethane complex of gossypol and single crystal conservation after decomposition

The structures of gossypol complexes are extremely sensitive to the halogenomethane present as the guest; e.g. changing the number of Cl atoms in chloromethane derivatives changes the structure of the gossypol complex. The crystals of C₃₀H₃₀O₈·CH₂Cl₂ are monoclinic, space groupC2/c,a=21.320(4),b=19.199(6),c=15.765(2)Å, =113.05(2)^o,V=5916(2)ų,Z=8,D _x=1.35 g/cm³,T=295 K. The structure has been solved by direct methods and refined to the finalR value of 0.084 for 1828 reflections. In the structure H-bonded gossypol molecules form columns, generating channels in the structure which are filled by guest molecules. After decomposition (desolvation) monocrystals of the complexes are conserved without destruction, in which there are rather wide and empty channels though slightly smaller than in the complex. An attempt is made to explain some peculiarities of the behavior of the gossypol polymorph formed on the basis of its structure with empty channels. Supplementary data relevant to this article have been deposited with the British Library Publication No. SUP 82165 (17 pages).     

新型含葡萄糖基手性Salen配体及其Mn3+、Fe3+、Co2+、Cu3+配合物的合成与表征

A novel chiral Salen ligand with a glucose moiety was synthesized from the condensation of 1,2:5,6-di-O-isopropylidene-3-O-methylene-[5-(3-tert-butyl-2-hydroxy benzaldehyde)]-α-D-glucofuranose with (1R,2R)-1,2-diaminocyclohexane. Several chiral complexes of Mn³⁺, Fe³⁺, Co²⁺ and Cu²⁺ were prepared from this ligand. Both the ligand and the complexes were characterized by elemental analysis, NMR, IR, MS, and UV-Vis.     

9-羟基-芴-9-羧酸双核铜配合物[Cu(C_(14)H_8O_3)(C_9H_7N)(C_2H_5OH)]_2的合成、晶体结构及热稳定性研究

在自然界中,α-羟基羧酸广泛的存在于动植物体内,在羧酸循环、碳水化合物代谢和氨基酸的合成中起到重要的作用。Tapscott等详细总结了有关羟基羧酸及其金属配合物的合成化学[1]。芴的9位上2个氢原子被羟基和羧基取代可生成9-羟基-芴-9-羧酸(简称芴酸),它是α-羟基乙酸的衍生物,是一种具有生理活性的植物生长整形素,它能够延缓植株生长,影响植株根的向地性和茎的向光性[2]。由于芴酸含有羟基和羧基两种不同的氧配位原子,使其又可以作为一种潜在的构筑配合物的组织基元。目前有关芴酸与金属离子的合成与结构化学研究相对较少,仅见铜、镉的单…     

Development of the FTIR properties of nano-structure silica gel doped with different rare earth elements,prepared by sol-gel route

Structural characteristics of pure silica gel (silica-xerogel, SiO₂) and silica gel doped with some rare earth elements (REEs) such as, praseodymium Pr³⁺, and Europium Eu³⁺, Erbium Er³⁺ and Holmium Ho³⁺ ions, with different concentrations ranging from 1 up to 6%, in the form of monolith materials were prepared by sol-gel technique, Using tetra-ethoxysilane as precursor materials, which are of particular interest for sol-gel integrated optics applications. Some structural features of sol-gel derived monolith are analyzed, namely the structure of nano-particle momolith samples, based on X-ray diffraction (XRD) and Fourier Transform Infrared (FTIR). We show that the XRD spectra of α-crystobalite are obtained for the pure samples at 1100°C and even by doping with the four REEs ions.     

Manifestation of diamagnetic chemical shifts of proton NMR signals by an anisotropic shielding effect of nitrate anions

A remarkable upfield shift of the py_α protons of complexed 2,2′-bipyridine in [cis-Pd(bpy)(NO₃)₂] is observed which is considered to originate from the anisotropic influence of suitably positioned coordinated nitrate anions around the Pd(II) centre of the molecule. A typical complexation-induced downfield shift is observed for the NH₂ protons in [cis-Pd(en)(NO₃)₂] where ‘en’ stands for ethylenediamine.     

Mössbauer Spectroscopic Studies of Chlorostannate(II) Complexes in Frozen Aqueous Solutions

Mössbauer parameters of frozen aqueous solutions of Sn(ClO₄)₂ in 0.5 M HClO₄ did not change with the concentration of NaClO₄, so that it was used to keep the ionic strength at the desired level. When NaCl was added into Sn(ClO₄)₂ solutions, isomer shift did not change, but quadrupole splitting did. Therefore, stability constants were calculated from the quadrupole splitting data, which were in good agreement with the published values. The observed spectra could be resolved into components.     

在PVA存在下Os-SnCl_2-亮绿离子缔合体系的研究高纯镍中微量Os的测定

本文研究了Os-SnCl_2-PVA-亮绿离子缔合体系的显色反应,摩尔吸光系数ε_(434)为5.6×10~6L·mol~(-1)·cm~(-1),锇含量在0.1～0.7μg/25mL范围内遵守比耳定律,室温下显色后,吸光度在110min内稳定。研究了30种外来离子的影响,并进行了高纯镍中微量锇的测定。     

金属配合物高效液相色谱法测定人发和血清中锌,钴,铜的含量

选用8-羟基喹啉为配合剂，经柱前衍生后高效波相色谱法分离测定，建立了人发和血清中微量元素锌、钴、铜的含量测定方法，该法配合产物稳定性好，标准曲线的线性范围锌、铜均为0．8～4．0mg／L，钴为0．1～2．0mg／L，相关系数均0．999以上，批内、批间相对标准偏差均小于5％，加样回收率锌为（100．3±0.47）％，钴为（98．9±2．07）％，铜为（100.9±0．65）％。     

主体分子六次甲基四胺与客体分子二氯化六水合钴(Ⅱ)和结晶水包结物的研究

用X射线单晶衍射分析法研究主体分子六次甲基四胺与客体分子二氯化六水合钴（Ⅱ）和结晶水包结物晶体结构。其分子式为［（CH2）6N4］2·［（Co（H2O）6］Cl2·4H2O，Mr＝59038。晶体属三斜晶系，空间群为P1。晶胞参数：3341个衍射点，其中3148个独立衍射点，2754（F0＞6σ（F0））为可观察反射点。在晶胞内，客体分子和结晶水形成氢键：，客体分子与主体分子形成氢键晶胞之间形成氢键晶胞之内和晶胞之间主体分子和客体分子以及结晶水以氢键和范德华力相联系形成稳定的晶格。     

轻希土硫氰酸盐与2, 3, 11, 12, -四苯基-1, 4, 7, 10, 13, 16-六氧-2, 11-十八环二烯配合物的合成及XPS研究

合成了六种轻希土硫氰酸盐与标题不饱和冠醚的新固体配合物,进行了元素分析,摩尔电导率、DTA、UV、IR和XPS等表征.对Ln(NCS)₃·L和Ln(NCS)₃的XPS研究中,得到它们组成原子芯能级电子(Ln3d_5/2,Ols,Nls,S2p)的结合能信息;观察到除Y3d_5/2外Ln3d_5/2(Ln=La、Ce、Pr、Nd、和Sm)的伴峰结构,Ln3d_5/2结合能与原子序数呈线性关系,并推断类似化合物Pm³d_5/2结合能在1035eV附近.