稀土冠醚络合物的研究

稀土冠醚配合物由于其有趣的稀土／冠醚配比和结构以及其在稀土萃取分离、光谱探针等方面应用的可能性，引起了人们极大的研究兴趣，在固体配合物合成、晶体结构、配合物稳定性、冠醚在稀土萃取分离中应用等方面展开了广泛的研究。但是，对于不同配比配合物的反应机理及本质的探讨尚注意不够；三元配合物的合成工作较少；冠醚对稀土元素萃取需要有大体积对阴离子存在，且萃取效率不高，分离因数低。所有这些表明，对稀土冠醚配合物的合成及其性质，有必要作进一步深入的研究。本论文以冠醚(2,2)及其衍生物以及18－冠－6作为配体，研究其稀土配合物的结构及性质，取得了一些有意义的结果。1．合成轻稀土La-Nd硝酸盐与冠醚(2,2)配合物并测定了它们的晶体结构。晶体属于三斜晶系，空间群PT。随着原子序数增加，晶胞体积减小。配合物中，中心离子位于冠醚环中心，三个硝酸根均以双齿形式配位，其中两个位于位阻较小的冠醚环一侧，另一个位于其对侧。中心离子的配位数为12。指出硝酸稀土冠醚(2,2)配合物存在着两种不同的结构: [Ln(NO_3)_3(2,2)I (Ln = La - Sm); [Ln(NO_3)_2(2,2)]NO_3 (Ln = Eu)。用“堆积原理”解释了这种结构差异的原因。2．原INDO法计算了配合物La(NO_3)_3(2,2)的净电荷分布、电子结构、键级。用XPS验证了净电荷分布计算结果。键级计算结果表明，镧与配位原子间的键具有一定程度的共价性。镧的5d轨道对共价成份的贡献最大，而4f轨道基本上不参与成键，镧与冠醚环上氮原子间具有较强的作用，从而提高了稀土冠醚(2,2)配合物的稳定性。3．合成了稀土苦味酸盐与冠醚(2,2)配合物。元素分析结果指出：La、Pr-Sm配合物为无水的1:1配合物，Eu-Lu配合物为含水配合物。用IR、NMR、TG研究了La、Pr-Sm四个配合物的性质。IR研究结果表明，冠醚环上C-O-C、C-N-C反对称伸缩振动频率在形成配合物后向低波数位移40 cm~(-1)左右。N－H伸缩振动频率向低波数位移并发生分裂，其中一个分裂峰位移达-130 cm~(-1)。配位后，苦味酸C－O伸缩振动频率向低波数位移约10 cm~(-1)，苯环上硝基面外摇摆振动发生分裂，表明苦味酸以酚氧原子及硝基氧原子参与配位。~1H NMR结果表明，配位后，冠醚环上质子向高场位移。4．合成了未见文献报道的十五个稀土－PMBP－18C6三元配合物。元素分析结果指出配合物组成为1:3:1，用IR、NMR、FAB－MS TG－DTA研究了配合物性质。IR结果指出：形成配合物后，冠醚C－O－C反对称伸缩振动频率位移较小，表明了稀土与冠醚间的作用较弱。FAB－MS中[Ln(PMBP)_2·18C6]~+谱峰丰度小于[Ln(PMBP)_2]~+，也反映了三元配合物中稀土与冠醚间的较弱的作用，表明三元配合物的稳定性不如二元配合物。选择La~(3+)、Lu~(3+)、Y~(3+)、Pr~(3+)、Eu~(3+)、Ho~(3+)的三元配合物进行了~1H NMR研究。对抗磁性离子La~(3+)、Lu~(3+)、Y~(3+)的配合物，与自由配体比较，各组质子均向高场位移。顺磁性离子Pr~(3+)、Eu~(3+)配合物中，PMBP苯环质子发生更大位移，同时谱峰宽化。冠醚环上质子及PMBP甲基质子共振峰消失。Ho~(3+)配合物由于强烈的宽化作用而没有出现质子核磁共振信号。5．研究冠醚(2,2)的两种衍生物对Pr~(3+)的萃取行为，结果表明，在没有大体积对阴离子存在下，冠醚对Pr(NO_3)_3能有较高的萃取率，这种现象尚未见文献报导。考察了冠醚浓度、稀土浓度等对萃取分配比的影响，随着冠醚浓度增加，萃取分配比增加，而稀土浓度增加时，萃取分配比下降。

稀土——冠醚配合物的合成、结构、性质及应用研究

近20年来，冠醚类化合物的络合选择性以及稀土——冠醚络合物在结构和性质上的特殊性一直吸引着人们的研究兴趣，研究稀土冠醚的配位作用，探讨冠醚在稀土分离，作为光谱探等方面的应用一直为人们所重视，并取得了丰富的研究资料，但由于稀土冠醚配位作用的复杂性，目前人们尚无法解释许多实验事实，因此，有必要进行配合物的深入研究，同时考虑到目前高纯稀土生产中，对少量的矸金属、矸土金属杂质仍无十分有效的分离方法，而冠醚对矸金属、矸土金属的配位能力大于稀土，利用冠醚有可能实现这一分离，为此我们完成了如下工作：研究了水合稀土硝酸盐与B12C4、Cy12C4和B15C5络合物的合成结构和性质。对于B12C4，轻重稀土均可得到稳定的无水络合物（1：1），对Pr、Cd、Lu的络合物的晶体结构分析表明，三者具有相同的结构特征。Cy12C4表现出了与B12C4相似的配位性能，它与轻重稀土均可得到稳定的无水络合物；对La、Eu、Lu络合物的晶体结构研究表明，La、Eu络合物中三个NO_3~-呈不对称排列，这在“伞型”结构的稀土硝酸盐络合物中尚无报道；对于B15C5，轻重稀土表现出了不同的配位能力，其中，轻稀土络合能力较强，可以得到无水的直接配位络合物R(NO_3)_3、B15C5(R=La-Gd)，但Sm和Gd络合物的稳定性已变差，晶体结构及红外数据表明，这些络合物具有相同的结构特征；重稀土与B15C5得到含水配恰 物；通过对典型含水重稀土络合物Yb(NO_3)_3、3H_2O、B15C5和的结构和性质研究，指出B15C5不参与中心离子配位是含水重稀土-B15C5络合物的结构特点。研究了La(NO_3)_3、L(L=16C5, Me_216C5)及Lu(NO_3)_3、3H_2O、16C6的合成结构和性质，分析了它们的结构特点。初步总结了水合稀土盐与冠醚的配位特点，分析了1：2冠醚直接配位型络合物难以形成的原因及影响冠醚与水配竞争的因素，总结了稀土——冠醚络合物的结构特征。用INDO法研究了Lu(NO_3)_3、B12C4及Lu(NO_3)_3、Cy12C4电子结构，比较了取代基苯环和单环已基对配体配位性能的影响。研究了DCC对HNO_3溶液中Ca和La的萃取，指出DCC对硝酸镧基本不萃取，对Ca萃取率可达20%。因而具有明显的分离作用。

中性芳烃烯土氯化铝配合物的合成结构及催化反应性能

本文以经铝粉活化的AlCl_3与无水氯化稀土在芳烃溶剂中反应，分离到了一系列含有不同芳烃配体的中性芳烃稀土氯化铝配合物。对这些配合物进行了元素分析和水解色谱分析，证实了配合物的组成。这是迄今为止继Cotton 报道的S_m(C_6Me_6)(AlCl_4)_3之后仅有的溶液中合成的芳烃配合物的例子。对配合物进行了红外、校磁共振谱的测定，发现配合物中配合体的特征吸收和化学位移与游函的配体一致，说明配合物中配体与中心金属函子的作用较弱。对典型的配合物进行了X－射线晶体结构测定。对含相同中心函子不同配体的配合物结构研究发现，在配体与中心金属函子的作用中，电子效应和空间效应同时反方向起作用，即电子效应加强配体与中心金属函子的作用，空间效应阻碍配体与中心金属离子作用。这两种作大约在二甲基苯为配体时达到平衡。其后，随着电子性的甲基增多，两种效应对配体与中心金属离子作用的影响相互抵消。同时对含有相同配体不同中心金属离子的配合物的结构研究中发现，中心金属离子对配合物的结构没有明显的影响，其键参数的差别主要来自离子半径的变化。对配合物的电子结构进行了研究。对S_m(CH_3C_6H_6)(AlCl_4)_3的INDO计算表明：1．配体甲苯环上电子云密度有所下降，并且邻、对位下降幅度较间位大、六个环上C原子电子云分布与游离和甲苯比较差别缩小。2．环上H原子的电子云密度降低，说明配位对环上H原子有一定的活化作用。3．中心离子的正电荷下降。中心稀土离子主要以5d、6s、6p参与成键。用L_a(C_6H_6)(AlCl_4)_3和Nd(C_6H_6)(AlCl_4)_3作催化剂研究了苯与已烯－1的烷基化反应，发现配合物的催化活性比相应的氯化稀土大，这可能是由于配合物的生成使Zn~(3+)在芳烃菏剂中可以均相存在，因而提高了催化剂的活性。另外发现，反应在较低产率即达到平衡，这可能是存在着已烯－1与苯在催化剂上的络合一释络平衡。

A theoretical study on the nonlinear optical second-order properties of azobenzene series molecules

On the basis of AM1 and INDO/CI methods, we devise the program for the calculation of nonlinear second-order optical susceptibilities beta(ijk) and perform systematic theoretical studies on the nonlinear optical second-order properties of azobenzene series molecules, i. e. on the basis of [GRAPHICS] we induced different donors on the left side of phenyl ring, and different accepters on the right side of phenyl ring, and examined the rule of beta variation. The regularity summarized from the calculated results has been explained micromechanically. Finally, a molecule having a big nonlinear second-order optical susceptibility has been designed.

STUDY ON BONDING AND 4F ORBITAL EFFECT OF LANTHANIDE COMPOUNDS

The bonding and the 4f orbital effect of lanthanide elements at different valence state in their compounds have been studied by INDO method in this paper. The results obtained show that the bonding of lanthanide compounds is affected by many factors, such as valence state, ionic radius, ligand, coordinate number, space configuration etc. The strength of bonds composed of different ligands with lanthanide is distinctly different. The covalence of Ln-L bonds of lanthanide ions at high valence state in their compounds is larger than that at low valence state, The covalency at low coordinate number is larger than that at high coordinate number. Some lanthanide compounds with special configuration, besides sigma-bond, can form p(pi)-d(pi) dative bond with much overlap, which makes the Ln-L bond increase markedly. The effect of 4f orbitals on bonding is far less than that of 5d orbitals. The Ln 4f orbitals at 3 or 2 valence state may be considered to be essentially localized, while the contribution of 4f orbitals on bonding in 4 valent cerium compounds increases obviously, up to 1%.

苯基稀土钆配合物的成键性质研究

苯基稀土钆配合物具有Ln-Cσ键,由于这类配合物不稳定且分离困难,故其研究工作开展得很少~[1,2],其电子结构的研究尚未见报道.最近,我们合成了新型的苯基稀土配合物C_6H_5LnCl_2·nTHF(Ln=Pr、Sm、Gd,n=3,4)并测定了其晶体结构~[3],本文报道了苯基稀土钆配合物的电子结构和成键性质,并与中性苯稀土配合物的成键性质~[4]进行了比较.

稀土中性苯配合物的化学键及其配位活化

用INDO方法研究了稀土中性η~0-苯配合物的电子结构及其化学键的配位活化。计算结果表明,NdCl_3和AlCl_3通过Cl桥键联的配位作用降低了钕离子的Lewis酸性和Nd-Cl之间的电荷差及其键的极性,导致NdCl_3在苯中溶解度的增大,从而有利于苯分子跟钕离子的配位反应。苯跟钕离子的配位降低了其C-C和C-H键的强度,使苯环上的烷基化反应易于进行。

稀土双氧配合物的电子结构研究

用INDO方法(间略微分重叠法)研究了[Ce(CO_3)_3O_2]_2~(8-)上的电子结构和化学健。研究结果表明,[Ce(CO_3)_3O_2]_2~(8-)的HOMO主要由双氧离子(O_2~(2-))的反键π~*轨道组成,LUMO主要由四价铈的4f轨道组成。双氧离子通过σ配键和π配键与2个铈离子配位,配位后O—O键增强。与三价铈配合物比较,四价铈配合物中4f轨道对成键的贡献增大。

镧系元素混价配合物的电子结构 Ⅰ.三价铈和四价铈的成键研究

不久以前,本文的作者之一在试图合成C_9H_7CeCl_3时,得到了非预期产物[Ce(THF)_5Cl_2]~+[Ce(THF)Cl_5]~-(THF=四氢呋喃)的单晶,并测定了其晶体结构,该混价配合物的分子由合Ce(Ⅲ)的配阳离子和含Ce(Ⅳ)的配阴离子组成,它的培养成功为研究铜系元素4f轨道的成键作用及对比镧系离子价态变化对其成键的影响提供了一个极好的机会。本文用INDO方法研究了铈离子混价配合物的电子结构和成键性质。

硝酸镧与冠醚(2,2)配合物的晶体及电子结构研究

用X-射线单晶衍射法测定了硝酸镧与冠醚(2,2)配合物的晶体结构,发现其具有与报道的Eu(NO_3)_3(2,2)配合物不同的配位方式.晶体属于三斜晶系,空间群P(?),晶胞参数为a=10.312(2)(?);b=12.745(3)(?);c=8.917(2)(?);α=103.79(2)°;β=112.73(2)°;γ=83.68(2)°;V=1049.5(5)(?)~3;F(000)=587.88;Z=2.结构用重原子法解出;R值为0.0292.用INDO法计算了配合物的净电荷分布,电子结构、键级.结果表明,镧与配位原子间的键具有一定程度的共价性.镧的5d轨道对共价性的贡献最大,而4f轨道基本上不参与成键.La-N比La-O(醚)间存在较强的作用,增大了配合物的稳定性.

ELECTRONIC-STRUCTURE AND CHEMICAL BONDING OF EUROPIUM NITRATE COMPLEX WITH AZACROWN (2, 2)

The electronic structure and bond character of europium nitrate complex with azacrown (2, 2)(1, 7, 10, 16-tetraoxa-4, 13-diazacyclooctadecane), [Eu(NO_3)_2(2, 2)] NO_3, have been studied by means of XPS and INDO method. The data of electronic binding energies and charge distribution of atoms in the complex showed that chemical shift of less electronegative nitrogen N1s binding energy was larger than that of more electronegative oxygen O1s binding energy in coordinating atoms, and that charge transfer from N...

稀土氨基酸配合物的电子结构与化学键性质

本文用INDO方法研究了稀土甘氨酸配合物([Er(H_2O)_4(NH_3CH_2COO)_2]_2~(6+))的电子结构和化学键性质。配合物的HOMO由甘氨酸羧基氧O_2p轨道组成,LUMO由羧基的π*(C-O)轨道组成。在配位过程中随L→Ln电荷转移,四个桥联甘氨酸和八个配位水分子分别转移2.59和1.86个电子到铒离子上,与配合物中铒离子带0.77个正电荷结果吻合。转移至5d轨道的电荷最多。配合物具有一定的共价性。对配键有主要贡献的是5d轨道。

硝酸铕与含氮冠醚配合物的电子结构和化学键

本文用XPS和INDO方法研究了硝酸铕与含氮冠醚配合物[Eu(NO_3)_2(2,2)]NO_3的电子结构。结合能和电荷分布数据指出,在配位原子中,电负性低的氮原子Nls结合能的化学位移比电负性高的氧原子Ols的大。在配合物中,氮原子转移至中心金属离子上的电荷比氧原子转移的多。铕与含氮冠醚配合物的化学键具有一定程度的共价性,电负性低的氮原子与铕的配位键(N→Eu)的共价性比电负性高的氧原子的配位键(O→Eu)的大。

Mesozoic-Cenozoic tectonic evolution of the Zhuanghai area, Bohai-Bay Basin, east China: the application of balanced cross-sections

The technique of balancing cross-sections, an important method for studying the tectonic history of sedimentary basins, has many applications. It enables one to compile charts for petroleum exploration and development, and growth sections of ancient structures can be restored so that the structural growth history can be studied. In order to study tectonic evolution in the Zhuanghai area of the Bohai-Bay basin, we selected two seismic profiles and compiled two structural growth sections. Based on the two balanced cross-sections, the evolution can be divided into four phases: the Triassic-Middle Jurassic phase, Late Jurassic - Cretaceous phase, Palaeogene extension phase, and Late Palaeogene-to-present phase. The whole area was uplifted during the Triassic-Middle Jurassic phase because of intense extrusion stress related to the Indo-China movement. During the Late Jurassic and Early Cretaceous, intense extension occurred in east China, and the whole area rifted, leading to the deposition of a thick sedimentary sequence. In the Late Cretaceous, the area suffered uplift and compression associated with the sinistral strike slip of the Tanlu fault. In the Palaeogene, a rifting basin developed in the area. Finally, it became stable and was placed in its present position by dextral strike-slip motion. In addition, some problems associated with compiling balanced cross-sections are discussed.

渤海湾盆地前第三系构造演化与煤成气成藏研究

The disequilibrium between supply and demand the east part of North China accelerated natural gas exploration in Bohai bay basin. Exploration practice showed that coal-derived gas is important resource. In searching of big to middle scaled coal derived gas field, and realize successive gas supply, the paper carried out integrated study on structural evolution of Pre-Tertiary and evaluation of reservoir forming condition of coal-derived gas. Study work of the paper was based on the following condition: available achievement in this field at present, good understanding of multiphase of tectonic movement. Study work was focused on geological evolution, source rock evaluation and dissection key factors controlling reservoir forming. Based on analysis of seismic data, drilling data, tectonic style of Pre-Tertiary was subdivided, with different tectonic style representing different tectonic process. By means of state of the art, such as analysis of balanced cross section, and erosion restoration, the paper reestablished tectonic history and analyzed basin property during different tectonic phase. Dynamic mechanism for tectonic movement and influence of tectonic evolution on tectonic style were discussed. Study made it clear that tectonic movement is intensive since Mesozoic including 2 phase of compressional movement (at the end of Indo-China movement, and Yanshan movement), 2 phase of extensional movement (middle Yanshan movement, and Himalayan movement), 2 phase of strike slip movement, as well as 2 phase of reversal movement (early Yanshan movement, and early Himalayan movement). As a result, three tectonic provinces with different remnant of strata and different tectonic style took shape. Based on afore mentioned study, the paper pointed out that evolution of Bohai bay basin experienced the following steps: basin of rift valley type (Pt2+3)-craton basin at passive continental margin (∈1－2)-craton basin at active continental margin (∈3- O)-convergent craton basin (C-T1+2)-intracontinental basin (J＋K). Superposition of basins in different stage was discussed. Aimed at tectonic feature of multiple phases, the paper put forward concept model of superposition of tectonic unit, and analyzed its significance on reservoir forming. On basis of the difference among 3 tectonic movements in Mesozoic and Cenozoic, superposition of tectonic unit was classified into the following 3 categories and 6 types: continuous subsidence type (I), subsidence in Mesozoic and uplift for erosion in Cenozoic (II1), repeated subsidence and uplift in Mesozoic and subsidence in Cenozoic (II2), repeated subsidence and uplift in Mesozoic and uplift for erosion in Cenozoic (II3), uplift for erosion in Mesozoic and subsidence in Cenozoic (II4), and continuous uplift (III). Take the organic facies analysis as link, the paper established relationship between sedimentary environment and organic facies, as well as organic facies and organic matter abundance. Combined information of sedimentary environment and logging data, the paper estimated distribution of organic matter abundance. Combined with simulation of secondary hydrocarbon generation, dynamic mechanism of hydrocarbon generation, and thermal history, the paper made static and dynamic evaluation of effective source rock, i.e. Taiyuan formation and Shanxi formation. It is also pointed out that superposition of tectonic unit of type II2, type II4, and type I were the most favorable hydrocarbon generation units. Based on dissection of typical primary coal-derived gas reservoir, including reservoir forming condition and reservoir forming process, the paper pointed out key factors controlling reservoir forming for Carboniferous and Permian System: a. remnant thickness and source rock property were precondition; b. secondary hydrocarbon generation during Himalayan period was key factor; c. tectonic evolution history controlling thermal evolution of source rock was main factor that determine reservoir forming; d. inherited positive structural unit was favorable accumulation direction; e. fault activity and regional caprock determined hydrocarbon accumulation horizon. In the end, the paper established reservoir forming model for different superposition of tectonic units, and pointed out promising exploration belts with 11 of the first class, 5 of the second class and 6 of the third class.