Dy3+在Ba3La(BO3)3 中的光致发光

研究了Ba3La(BO3)3 基质中Dy3 的光致发光特性; 探讨了RE3 的电荷半径比(z/r)和Ce3 , Dy3 含量对Dy3 发光强度及发光颜色的影响; 分析了Ba3La(BO3)3 中Ce3 对Dy3 发光的敏化作用; 确定了Dy3 的 4F9/2→6H15/2及4F9/2→6H13/2跃迁发射的浓度猝灭机制均为电偶极-电四极相互作用.     

钙钛矿CH3NH3PbI3晶体的电化学

电化学方波伏安及循环伏安测量表明,钙钛矿CH₃NH₃PbI₃晶体在有机电解质中的氧化还原过程伴随着化学降解。该化学降解源于CH₃NH₃PbI₃晶体中铅离子的还原以及碘离子的氧化。通过电化学伏安法可以测定晶体的能带。     

[{(C5Me4R)Ru}3Ru(η3-As3)(μ3,η3-As3)(μ3-As)3], arsenreiche Vierkerncluster

The interaction of [(η⁵-C₅Me₄R)Ru(CO)₂]₂ (1a: R = Me, 1b: R = Et) with yellor arsenic, As₄, affords besides the pentaarsaruthenocenes [(η⁵-As₅)Ru(η⁵-C₅Me₄R)] (2a, 2b) the tetranuclear clusters [{(η⁵-C₅Me₄R)Ru}₃Ru(η³-As₃)(μ₃,η³-As₃)(μ₃-As)₃] (3a, 3b). The structure of 2b and 3b has been elucidated by X-ray analysis.     

Non-Isothermal Kinetics of the Decomposition Reaction of Cluster [Ag3WS3Br]（PPh3）3 and [Cu3WS3Br]（PPh3）3

The thermal behaviors of clusters [Ag3WS3Br](PPh3)3 and [Cu3WS3Br](PPh3)3 (PPh3=triphenyl phosphine) in a nitrogen atmosphere were studied under the non-isothermal conditions by simultaneous TG-DTG-DSC and EDS techniques. The results showed that the evolution of PPh3 generally proceeded before the release of the other moiety in one or two step-mode. The mechanisms, the kinetic and the thermodynamic parameters for decomposition of PPh3 of both clusters were determined and calculated by jointly using several methods, which showed that its evolution was controlled by Avrami-Erofeev equation. The results also showed that there was no new stable phase composed of W-Ag(Cu)-S-Br after release of organic moiety PPh3 and that CVD method was not applicable to their further processing.     

有关NdCl_3·3ROH-AlEt_3催化体系的活性

<正> 我们曾指出,在NdCl_3·3ROH-AlEt_3体系中,醇的作用在于它的给电子性将会降低稀土离子的正电性,从而减弱Nd-Cl键的离子性,同时引起晶格的变化,使之有利于烷基化作用的发生,导致活性提高。本实验采用一种简便的方法证实了这种作用的发生。 这个方法所根据的原理是一般Ziegler-Natta型催化组分的熟知反应形式:     

LaVO3和NdVO3的合成

以Ｖ２Ｏ３为起始原料，在氩气中合成了ＡＢＯ３型稀土钒化合物，对加热前通氩气的时间，Ｖ２Ｏ３∶Ｌａ２Ｏ３的配比等进行了探讨，得到了适宜的制备条件。首次报道了ＬｎＶＯ３（Ｌｎ＝Ｌａ，Ｎｄ）的热学性质，发现ＬａＶＯ３具有吸附二氧化碳的特性。     

KMgF3:Ce3+,Tb3+纳米粒子中Ce3+→Tb3+的发光及能量传递

利用微乳液方法,合成了铈、铽共掺杂的氟镁钾纳米粒子,研究了体系中Ce3+→Tb3+的发光特性以及它们之间的相互作用,结果表明KMgF3:Ce3+Tb3+纳米粒子中存在Ce3+→Tb3+的能量传递过程,即Ce3+可以将吸收的能量直接传递给Tb3+离子,使得Tb3+的绿色发光强度大为增加.     

异戊二烯在Nd(naph)_3-Al(i-Bu)_3-Al_2(C_2H_5)_3Cl_3催化体系作用下聚合动力学

本文研究了异戊二烯在稀土催化剂作用下聚合动力学的一般规律。通过稳态处理及分段聚合证明,体系的活性中心数目基本稳定。聚合转化率低于50％时,聚合速率与单体浓度呈一级关系,同催化剂浓度为1.7级关系。聚合表观活化能为9.0千卡/克分子。聚合物的特性粘数随转化率增加而增大的事实,说明本体系具有某些“活性”聚合的特性。     

Fe3(CO)8(C6H5NC)(μ3-S)2的合成和晶体结构

The title compound Fe_3(CO)_8(C_6H_5NC)(μ_3-S)_2 (Ⅰ) was synthesized by the reaction of C_6H_5NCS with Fe_3(CO)_12 at room temperature. The crystal and molecular structure of the title compound were determined by single ctystal diffraction method. Crystal data: monoclinic, space group P2_1/C, a=12.718(4)Å, b=26.164(10) Å, c=l3.741(7) Å, β=117.18(2) °, V=4067(2) Å3, Z=8, Dc=1.825 g/cm3. The structure was solved by direct method and difference Fourier synthesis, and refined by full-matrix Least-squares with anisotropic thermal paramaters, using 1990 observed reflections [Ⅰ＞3σ(Ⅰ)].The final residual factor was R＝0.076, Rw＝0.082. The substituted ligand (C_6H_5NC)in Fe_3(CO)_8(C_6H_5NC)(μ_3-S)_2 is connected to the Fe(3) atom of the distorted tetragonal pyramid Fe_3S_2 framework.     

一些Ag+、Cu+簇的合成和结构研究

由于银,铜簇合物有助于催化理论的研究,近20年来,许多学者对它们的合成方法、成簇规律和结构特点进行了许多探索。本文报道了[Me_4N]_6[Ag_6[S_2C=C(CN)_2)_6]·H_2O(Ⅰ)、[Et_4N]_4[Cu_8(S_2C=C(CN)_2)_6](Ⅱ)和[Me_4N]_4[Cu_5Ag_3(S_2C=C(CN)_2)_6]·H_2O(Ⅲ)的化学合成,化合物(Ⅰ)和(Ⅱ)的晶体和分子结构,以及从化合物(Ⅲ)的ICP元素分析和红外光谱分析,探讨它的结构特征。     

AB INITIO STUDIES ON THE INTERACTION BETWEEN CH3OH AND H2CO

The interaction between CH₃OH and H₂CO has been studied by abinitio method (6-311G basis set).It has been found that there are twopossible complexes:(Ⅰ)H-bond Br?nsted complex CH₃OH...OCH₂(Ⅱ)Donorscceptor Lewis complex CH₃OH...CH₂P.HF/6-311G stabilization energiesfor complex(Ⅰ)and complex(Ⅱ)are 25.1 and 17.1 kJ/mol respectively.     

苯并氮杂冠醚化合物在氘代氯仿中的溶剂效应的动态1H NMR研究

本文讨论了样品浓度对苯并氮杂冠醚化合物-氘代氯仿溶液~1H NMR镨及~1H纵向弛豫时间的影响(稀释位移效应)。在实验基础上提出了苯并氮杂冠醚化合物在氯仿中的叔胺-叔铵盐交换作用机制。以此馐土讼∈臀灰菩в? 并得到巳止诿鸦衔锎邮灏返绞屣а蔚姆从ζ胶獬Ｊ齂_2和交换速率常数k, 另外, 本文还讨论了冠醚环中氮原子上取代基对稀释位移效应的影响,     

Structural,Photoluminescent and Theoretical Evidence for Ligand-unsupported Argentophilic Interactions in a Supramolecular Aggregate of [Ag2（Hida）（NH3）2]

A new neutral [Ag2（Hida）（NH3）2] molecule （1, H3ida = 1H-imidazole-4,5-dicarboxylic acid） has been synthesized and structurally characterized by single-crystal diffraction. Compound 1 crystallizes in monoclinic, space group C2/c with a = 18.3928（8）, b = 8.3299（5）, c = 13.682（7） A, β = 113.179（2）°, V = 1926.9（10）A^3, Z = 8 and Dc = 2.784 g·cm^-3. In the solid state, this disilver（I） compound can aggregate to furnish the energetically stable ligand-unsupported Ag^I-Ag^I interaction concomitant with significant photoluminescence changes in different aggregate states, and such argentophilicity interaction is also supported by molecular orbital calculations.     

V2O5表面氧和晶格氧的热脱附性能

V_2O_5是一种重要的烃类选择氧化催化剂,ESR研究表明,在V_2O_5/SiO_2上存在有O~-,O~(2-)和O_3~-等物种。但是氧吸附物种的ESR研究迄今仍局限于较低温度,与实际催化反应条件尚存相当差距。用程序升温脱附(TPD)法研究,恰好能补其不足。但是关于V_2O_5表     

三核苯甲酸铁配合物[Fe3O(OBZ)6(H2O)3](NO3)(acetone)5(OBZ-=苯甲酸根)的结构和磁性

合成了三核苯甲酸铁配合物［Ｆｅ３Ｏ（ＯＢＺ）６（Ｈ２Ｏ）３］（ＮＯ３）（ａｃｅｔｏｎｅ）５。测定了其晶体结构，其中三个铁形成等边三角形结构。配合物的变温磁化率表明，分子内三个铁之间有弱的反应磁性交换作用，Ｊ＝－３３．１８ｃｍ＾－１。分子之间则有更弱的反铁磁性交换作用，ＺＪ＾＇＝－１．１４ｃｍ＾－１。     

簇合物配基置换反应的研究——Mo3S4(μ-dtp)(η2-dtp)2(η1-dtp)(bpy)的合成与晶体结构

应用X-射线单晶衍射方法, 测定2,2-联吡啶(bpy)和簇合物MO_3S_4(μ-dtp)(dtp)_3(H_2O)(Ⅰ)反应产物褰峁埂ａ果? 产物为Mo_3S_4(μ-dtp)(η~2-dtp)_2(η~1-dtp)(bpy)(Ⅱ), 即联吡啶置换了簇合物(Ⅰ)中的端基(H_2O)和端基(dtp)中的一啮。簇合物(Ⅱ)晶体属三斜晶系。晶胞参数为:a=1.3638(3); b=1.3983(3); c=1.4699(2) nm, a=95.57(2)°, β=91.87(2)°, γ=117.40(2)°; V=2.4676 nm; Z=2; D_C=1.767 g·cm~(-3)。晶体的空间群为P1。最终偏离因子R=0.069, R_w=0.076。本文结合过去对簇合物(Ⅰ)进行的四种不同类型的置换反应的研究, 进行了必要的讨论。并指出本文中的反应是松散本位促进的配基置换反应。     

超导体Ba2YCu3O6.92晶格中不同位置氧的热稳定性

Studies on high-T_c superconductor Ba_2YCu_3O_(6.92) using thermogravimetry, temperature programmed decomposition, oxygen isotopic exchange method are reported. There are six steps in the thermogavimetric graph of Ba_2YCu_3O_(6.92). At the first step, 0.40 oxygen atom per unit cell is released, the amount of which corresponds to that of the oxygen released from the CuO_4 square plane when the oxidation number of copper reduced from +3 to +2. This amount of oxygen plays a key role on the influence on the T_c of superconductor. At the is 0.45, corresponding to the amount of oxygen released from CuO_4 when the oxidation number of copper changed from +2 to +1. The oxygen atom released totally at the last three steps is 1.07 per unit cell, which correspondes to the oxygen released from CuO_5 square pyramid when the oxidation number of copper changed from +2 to +1. The first three steps are almost continuous, so in TPD curve there is only one peak at 514 ℃ with respect to the three steps in TG curve and the decomposition heat of this one is 171±8 kJ mol~(-1). Another peak which is over 900 ℃ on TPD curve is the result of the loss of oxygen from the last three steps in TG curve. The sample released oxygen can recover its supeconductivity after reabsorbing oxygen. Oxygen isotopic exchange method shows that the oxygen atoms of CuO_4 and CuO_5 groups can be interexchanged under certain temperature and indicates that there is some bonding between CuO_4 square plane and CuO_5 square pyramidal groups in the crystal lattice of Ba_2YCu_3O_(6.92).