氢谱在甾醇类化合物定量和纯度分析中的应用

用^1HNMR谱可定量确定繁茂膜海绵(Hymeniacidon perleve)中分离得到的结构类似的甾醇类化合物的含量，这种方法是对鉴定分析组成复杂而性质很相近的天然甾醇化合物的新思路。     

On the magnetic properties of Lithium Vanadium Bronzes LixV2O5

Magnetic susceptibility of V₂O₅ and of the α-, ?-, δ- and γ-Li_xV₂O₅ bronzes prepared either at high or at room temperature has been measured between liquid helium and ambient temperature. The results are representative of the localized character of the V⁴⁺ ion d-electron and, for high enough x-values, of the existence of antiferromagnetic interactions in a low dimensional system. The intrachain exchange integral J has been determined using the Bonner/Fischer model for Heisenberg chains with S = 1/2 spin. It is larger for the γ- than for the δ-phase. This result as well as the occurrence of long range ordering below T_N ≈ 130 K in the γ-phase may be ascribed to ordering of V⁴⁺ and V⁵⁺ ions in the former bronze and to the random distribution of V⁴⁺ ions in the latter one.     

磁疗手术胆结石的红外光谱观测

本文报道用Nicolet 170 SXFT-IR红外光谱仪观测磁疗手术胆结石、磁疗破碎排出胆结石及服中草药破碎胆结石的红外光谱,分析并比较了它们的光谱特征。     

Photolysis of a methanolic solution of benzyl acetate in low acoustic fields

The influence of low acoustic fields on the photolysis of benzyl acetate in solution was investigated. A change in the contributions of alternative photolysis mechanisms is caused by destruction of solvate shells.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 180–181, January, 1995.This study was financially supported by the Russian Foundation for Basic Research (Project No. 93-02-18102).     

2-芳基硫杂脯氨酸结构特征的研究

对12种2-芳基硫杂脯氨酸进行了红外光谱和核磁共振谱测定,对其中两个化合物作了质谱测定。结果表明,这类化合物固态时主要以两性离子形式存在;有较强的分子离子峰,是一类较稳定的化合物。它们还存在一对非对映异构体,芳环上的取代基对芳环电子云密度的影响较大,而对四氢噻唑环的影响较小。     

配位聚合物{[CoL][FeⅡFeⅢ(ox)3·1.5H2O]}∞的合成、波谱表征和磁学性质

A new Schiff base complex， CoL(ClO₄)·3H₂O (1) {L represents condensed from equal molar ratio of sali-cylaldehyde and diethylenetriamine} was synthesized and characterized. Further， a new coordination polymer， {[CoL][Fe^ⅡFe^Ⅲ(ox)₃·1.5H₂O]}_∞ (2)， was synthesized and characterized， where ox^2-=oxalate. The results of the IR and M?ssbauer spectra of 2 revealed that the coordination polymer exists 2-D layer structure in the solid state， and anions layer was formed by [^ⅡFe^Ⅲ(ox)₃]^- unit. The magnetic properties of 2 have been measured and the results indicate that there is magnetic ordering in the low temperature， which may arise from intermolecular ferromagnetic interactions or spin canted effects.     

配位聚合物{[MnL][FeⅡFeⅢ(ox)3·1.5H2O]}∞的合成及其磁学性质

合成和表征了一种新的Schiff碱配合物MnL(ClO4)*3H2O(1)(其中L为n(水杨醛)∶n(二乙撑三胺)=1∶1缩合而成的Schiff碱).1与FeSO4*7H2O和K3[Fe(ox)3]*3H2O(ox=oxalate)进一步反应,生成了双金属层状配位聚合物{[MnL][FeⅡFeⅢ(ox)3]*1.5H2O}∞(2).IR和Mssbauer谱测定结果表明,2具有二维层状结构,其阴离子层由[FeⅡFeⅢ(ox)3]-单元构成.变温磁化率(5K～100K)测试结果表明,2中的自旋载体之间存在反铁磁交换作用.5K时的磁滞现象表明2在低温时可能存在铁磁有序,这可能是亚铁磁或自旋倾斜造成的.     

Banana-shaped molecules peculiarly oriented in a magnetic field: (2)H NMR spectroscopy and quantum mechanical calculations.

The orientational properties of the banana-shaped liquid crystal 4-chloro-1,3-phenylenebis{4-[4'-(10-undecenyloxy)]benzoyloxy} benzoate (ClPbis11BB) are reported in the nematic phase under the effect of an external magnetic field. A new hypothesis, which states that the central ring of the aromatic core is oriented perpendicularly to the external magnetic field, is proposed. In support of this hypothesis, a series of studies based on (2)H NMR spectroscopy, both in the bulk and in solution, are discussed. (2)H NMR measurements on three selectively deuterium-labelled isotopomers are presented, together with DFT results from B3LYP/cc-pvDz calculations performed on the aromatic core. The rather flat shape of the investigated intramolecular energy surface allows for several different conformations to be populated, the computed magnetic susceptibilities of which are consistent with the proposed hypothesis of peculiar orientation of banana-shaped molecules. Moreover, the orientation of the magnetic susceptibility tensor is shown to be strongly dependent on the internal conformation of the banana-shaped molecules.     

一维链状锰(Ⅱ)三氮唑配合物的合成，结构与磁性质(英)

A novel one-dimensional chain manganese(Ⅱ) compound [Mn(trz)₂Cl][phthH], (trz=1,2,4-triazole, phthH=hydrogen phthalate), 1, was synthesized and structurally characterized. It crystallizes in monoclinic system, space group P2 /c with a=1.381 1(11) nm, b=0.815 5(7) nm, c=0.735 4(6) nm, β=94.667(15)°, V=0.825 5(12) nm³. It consists of one dimensional cationic manganese(Ⅱ) chain and uncoordinated hydrogen phthalate anions. The manganese(Ⅱ) ions are bridged with two 1,2,4-traizoles and one chloride anion along the cationic chain, in which the weak antiferromagnetic exchange occurs between manganese(Ⅱ) atoms. CCDC: 267461.     

双甘肽稀土配合物溶液结构的13C和1H NMR研究

~(13)C and ~1H NMR technique was used to study the interaction of Gly-Gly with heavy lanthanide cations Dy~(3+), Ho~(3+), Er~(3+), Tm~(3+) and Yb~(3+) in aqueous solution. The stability constants for the 1:1 and 1:2 complexes of Gly-Gly with Ho~(3+) and Yb~(3+) were determined from the titration curves of chemical shift versus concentration ratio of lanthanide to Gly-Gly. The solution structure of the Ln-Gly-Gly complex was analyzed based upon the ~(13)C and ~1H lanthanide-induced shifts and the results show that in the complex Gly-Gly is coordinated to the lanthanide ion through the carboxyl oxygens with the backbone of the ligand in an extended state.