三氯化稀土的还原反应及产物的反应性能的研究

本文研究了NdCl_2·nTHF、SmCl_2·nTHF、YbCl_2·nTHF与环辛四烯在室温下的直接反应。发现NdCl_2·nTHF、SmCl_2·nTHF可以在室温下与C_8H_8直接反应，分别得到NdCl_3·nTHF、ClNdC_8H_8·2THF；SmCl_3·nTHF，ClSmC_8H_8·2THF。反应速度NdCl_2 > SmCl_2。YbCl_2·nTHF在室温下不与环辛四烯发生反应。产物LnCl_3·nTHF和ClLnC_8H_8·2THF (Ln = Nd, Sm)已得到水解色谱、质谱、元素分析、红外光谱等的证实。推测反应接下式进行：LnCl_2·nTHF + C_8H_8 → [THFCl_2LnC_8H_8LnCl_2THF] → LnCl_3·nTHF + ClLnC_8H_8·2THF我们近一步研究了NdCl_2·nTHF与K_2C_8H_8的交换反应。结果表明从这一体系中得不到二价钕的有机金属化合物，而是得到了KNd(C_8H_8)_2。首次研究了以2摩尔萘锂为还原剂还原无水三氯化钕的反应，得到了组成为NdClLin (n < 0.3)的还原产物。该产物不溶于四氢呋喃，对空气、水汽比NdCl_2更为敏感。推测钕主要以一价形式存在。还研究了萘钠与三氯化铽的还原反应。三氯化钕的还原产物不与LiCl 形成络合物，而三氯化铽的还原产物却与LiCl形成络全物而溶于THF。为了进一步了解三氯化钕还原产物的性质，研究了其与环辛四烯的反应，结果表明它们也可以在室温下直接反应，并且这一反应比NdCl_2与C_8H_8的反应快。从反应混合物中分出两种产物：ClNdC_8H_8·2THF和[LiNd(C_8H_8)_2·4THF]·2THF，并测定了这二种产物的晶体结构。ClNdC_8H_8·2THF的晶体结构表明它属于单斜晶系，P2_1/C空间群。晶胞参数为a = 11.819(3)A，b = 12.651(3)A，C = 13.478(3)A，β = 122.97(2)°。[LiNd(C_8H_8)_2·4THF的晶体结构表明它是单斜晶系，C_c空间群。晶胞参数：a = 17.858(7)A，b = 13.243(4)A，c = 18.085(6)A，β= 106.52(4)°。

茚基稀土铁双核配合物的合成

本文通过元素分析，红外光谱，垫失重，质谱，核磁共振以及电子能谱的测定，确认合成了下述两种新型的过程金属稀土有机配合物：<1> NdCl_3 + NaCaH_7 →~(THF) C_9H_7NdCl_2·nC_4H_8O C_9H_7NdCl_2 · nC_4H_8O + NaFeC_5H_5 (co)_2·mC_4H_8O →~(THF) Na[C_9H_7NdCl_2Fe(co)_2C_5H_5]·C_4H_8O <2> SmCl_3 + NaC_9H_7 →~(LiCl)_(THF) C_9H_7SmCl_2·(LiCl)_2·nC_4H_8O C_9H_7SmCl_2·(LiCl)_2·nC_9H_8O + NaFe(co)_2C_5H_5·mC_4H_8O → Li_2[(C_9H_7SmCl_3·Fe(co)_2C_5H_5]·C_4H_8O这些化合物可涂于四氢呋喃，氯仿，丙酮，三氯乙酸，吡喀算溶剂，不溶于四氯化碳，汽油，笨等涤剂。对水和空气敏感，同硝酸发生激烈的反应。化合物的红外光谱图中1010cm~(-1)，865cm~(-1)为茚基特征吸收峰，1045cm~(-1), 910cm~(-1)为四氢呋喃分子的特征吸收峰。化合物垫失重图中出现了脱去一个四氢呋喃分子和两个羰基的垫失重谱。本文制备配体GH_7LnCl_2nTHF过程中，合成了一类新型的离子型金属有机配合物。通过元素分析，热失重，红外光谱的测定，确定了合成的化合物组成为[Na[C_4H_8O)_6][(CGH_7)_3Ln)_2Cl] 2 LnCl_3 + 6 NaC_9H_7 →~(THF) [(CGH_7)_3Ln)_2Cl][Na(C_4H_8O)_6] Ln = Nd, Sm 并测得了其晶体结构，Nd[Sm]的晶胞参数为：a = 12.553[12.550](A) b = 12.696 [12.653] (A) c = 10.630 [10.608] (A) α = 97.37 [97.76] (°) β = 91.65 [91.83] (°) γ = 87.19 [86.76] (°) V = 1672.4 [1665.9] (°)此类化合物的晶胞体积有V_(Nd) > V_(Sm)现象，符合镧系收缩的规律。化合物热失重图中表明，有27.5%的失重，相当于失去了六个四氢呋喃分子。化合物的红外光谱图中，1015cm~(-1), 865cm~(-1)为茚基特征吸收峰1055cm~(-1), 910cm~(-1)为四氢呋喃分子的特征吸收峰。这些化合物溶于四氢呋喃，不溶于汽油。对水和空气敏感。

伯胺N_(1923)与其它试剂对金属离子(Zn~(2+).Cd~(2+).RE~(3+))的萃取及协同萃取

胺类萃取剂具有其独特优点，特别是伯胺，因含有活泼氢，既能作为“阴离子交换剂”，又能与被萃的含氧金属络阴离了形成氢键而溶剂化，同时伯胺为一路易斯碱，可作为配体与某些金属离子形成配位键等，因而已广泛地用于金属离子的提纯与分离工业中。然而，1）为了寻找新的、更有效的萃取及协同萃取体系，以适应分析分离各种金属离子，改善金属离子的分离工艺；2）研究萃取和协同萃取的一般规律，探寻其内在规律性，充实完善萃取化学原理的内容；3）研究多元配合物的组成、结构和机理；4）系统地研究和比较不同结构胺类萃取剂与其它萃取剂对金属离子的萃取及协同萃取的相互作用，探讨多元配合物的形成条件等，因此，研究伯胺N_(1923)与其它萃取剂在不同酸度、不同条件，不同体系中对Zn(II)、Cd(II)、Re(III)的萃取及协同萃取具有一定意义。本文分别研究了伯胺N_(1923)与中性磷试剂对ZnCl_2、CdCl_2、Zn(SCN)_2的协同萃取；伯胺N_(1923)与HPMBP对RE（III）的协同萃取以及伯胺N_(1923)在不同介质中对Sc(III)的萃取机理等，并用得到了一些有意义的结果与结论。一、伯胺N_(1923)与中性磷萃取剂(TBP, DBBP)对Zn(II)、Cd(II)的协同萃取1. 伯胺N_(1923)与TBP、DBBP对ZnCl_2的协萃取 研究了伯胺N_(1923)与TBP、DBBP的正庚烷溶液从盐酸介质中对ZnCl_2的萃取机理，用斜率法、等摩尔系列法确定了协萃配合物组成为：(RNH_3Cl)_3·ZnCl_2·B、(RNH_3Cl)_2·ZnCl_2·B (B = TBP·DBBP)协萃反应为：ZnCl_2 + (RNH_3Cl)_3_((o)) + TBP_((o)) →~(K_(12)(TBP) (RNH_3Cl)_3·ZnCl_3·ZnCl_2·TBP_((o)) ZnCl_2+Z/3(RNH_3Cl)_(3(o)) + DBBP_((o)) → (RNH_3Cl)_2 · ZnCl_2·DBBP_((o))协萃配合物生成反应为：(RNH_3Cl)_3·ZnCl_(2(o)) + TBP_((o))→~(B_(12)(TBP) (RNH_3Cl)_3·ZnCl_2·TBP_((o)) (RNH_3Cl)_3·ZnCl_(2(o)) + DBBP_((o)) →~(B_(12)(DBBP) (RNH_3Cl)_2·ZnCl_2·DBBP_((o)) + RNH_3Cl_((o))同时发现，中性磷试剂对Zn(II)的协萃效应大小影响有下列关系：DBBP>TBP。并求得了协萃反应平衡常数和协萃配合物生成反应平衡常数。在研究溶剂对协同效应影响时发现，对芳香烃及其衍生物，分配比（D）与溶剂介电常数（ε）的关系为D_∝1/ε，而对芳香烃及其衍生物，分配比（D）与介电常数（ε）的关系为D_∝ε。讨论了温度对协萃反应的影响，对协萃配合物的IR、NMR谱也进行了研究。2.伯胺N_(1923)与TBP对Zn_(SCN)_2的协同萃取研究了伯胺N_(1923)与TBP的庚烷溶液从硝酸底液中对Zn(SCN)_2的萃取机理，用等摩尔系列法、斜率法确定了TBP和Zn(SCN)_2以及伯胺N_(1923)与TBP对Zn(SCN)_2的协萃配合物组成分别为：Zn(SCN)_2·3TBP. (RNH_3)_2Zn(SCN)_4·TBP,协谇反应为：Zn(SCN)_4~(2-) + (RNH_3NO_3)_(2(o)) + TBP_((o)) → (RNH_3)_2Zn(SCN)_4·TBP_((o)) + 2NO_3~-协萃配合物三种可能生成反应为(RNH_3)_2Zn(SCN)_(4(o)) + TBP_((o)) → ~(B'12) (RNH_3)_2Zn(SCN)_4·TBP_((o)) (a) (RNH_3NO_3)_(2(o)) + Zn(SCN)_2·3TBP_((o)) + 2SCN~-→~(β"12)→(RNH_3)Zn(SCN)_4βTBP_((o))+2TBP_((o))+2NO_3~- (b) (RNH_3NO_3)_(2(o)) + (RNH_3)_2Zn(SCN)_(4(o)) + 2SCN~- + Zn(SCN)_2.3TBP_((o)) →~(β"12)→R(RNH_3)_2Zn(SCN)_4.TBP_((o)) + 2NO_3~- + TBP_((o)) (c) 求得了协萃反应及生成反应的平衡常数，并由生成反应常数可知：β"'_(12) > β'_(12) > β"_(12)，即反应（c）对协萃配合物的生成贡献最大，其次反应（a），最小的是反应（b），同时还发现，不同阴离子对协萃效应影响有下列关系：SCN~- > Cl~_。并对协萃配合物的IR谱进行了研究，讨论了温度对协萃反应的影响。3. 伯胺N_(1923)与TBP、DBBP对Cd（II）的协同萃取研究了伯胺N_(1923)与TBP、DBBP的正庚烷溶液从盐酸介质中对Cd(II)的协同萃取，用等摩尔系列法、斜率法确定了协萃配合物组成为(RNH_3Cl)_2·CdCl_2·B，协萃反应及协萃配合物生成的反应分别为：CdCl_2 + 2/3 (RNH_3Cl)_(3(o)) + B_((o)) →~(K_(12)) → (RNH_3Cl)_2·CdCl_2·B_((o)) (RNH_3Cl_3)·CdCl_2_((o)) + B_((o)) →~(BR)(RNH_3Cl)_2·CdCl_2·B_((o)) + RNH_3Cl_((o))求得了协萃反应及生成反应平衡常数，计算了协萃反应的热力学函数值，结果还发现与Zn(II)协同萃取比较，协同效应大小有下列关系：Zn(II) > Cd(II)，由实验结果证实了“萃取效应大，则协萃效应小，反之，萃取效应小，则协同效应大”这一结论。并对协萃配合物的IR、NMR谱进行了研究。二. 伯胺N_(1923)与HPMBP对RE（III）的协同萃取研究了伯胺N_(1923)与HPMBP的二甲苯溶液在盐酸介质中对RE（III）的协萃机理（RE~(3+ = La~(3+), Pr~(3+), Eu~(3+), Gd~(3+), Tb~(3+), Er~(3+), Yb~(3+)和Y~(3+)）用斜率法及等摩尔系列法确定了协萃配合物组成为RNH_3Ln(PMBP)_4。求得了关于Pr(III)的协萃反应及生成反应的平衡常数值，协萃反应及生成反应分别为：Ln~(3+) + 4HPMBP_((o)) + RNH_3Cl_((o)) → RNH_3LN(PMBP)_(4(o)) + 4H~+ + Cl~- Ln(PMBP)_(3(o)) + RNH_3Cl_((o)) → RNH_3Ln(PMBP)_(4(o)) + H~+ + Cl~- 结果还发现协萃系数（R）随稀土元素的原子序数（Z）递变而出现“双峰效应”（未见文献报道），而且随RNH_3Cl浓度增加到某一一出现反协同效应。同时研究了关于Pr(III)协萃配合物的IR、NMR谱。三、伯胺N_(1923)在硝酸盐及硫氰酸盐混合介质中对Sc(III)的萃取研究了RNH_3NO_3在硝酸盐和硫氰酸盐混合介质中萃取Sc(III)的机理，结果发现，钪是以Sc(OH)_2~+形式萃入有机相的，且SCN~-, NO_3~-对RNH_3nO_3萃取Sc(III)具有协同效应，并且斜率法、连续变化法及PH值测定确定了萃取反应为：Sc(OH)_2~+ + SCN~- + 2(RNH_3NO_3)_(2((o)) → (RNH_3nO_3)_4.Sc(OH)_2SCN_((o)) Sc(OH)_2~+ + SCN~- + NO_3~- + (RNH_3NO_3)_(2(o)) → (RNH_3NO_3)_2.Sc(OH)(SCN)NO_3 + OH~-求得了反应的平衡常数及热力学函数值。

环戊二烯基轻稀土氯化物的合成及其稳定性的研究

I LnCl_3-LiCl-THF配合物的研究深入地研究了氯化稀土和氯化锂于四氢呋喃溶液中，以不同的摩尔比，在不同条件下的反应。实验结果表明，反应速度随着稀土元素原子半径的减小，LiCl/LnCl_3摩尔比的增大，以及四氢呋喃用量的增加而加快。通过紫外质谱元素分析和X-射线单晶结构分析等证明，随着不同的LiCl/LnCl_3摩尔比和结晶条件的不同，可以得到不同组成的LnCl_3-LiCl-TNF配合物。对(LaCl)(THF)_2(μ_2-Cl)_4[Li(THF)_2]_2和(LaCl)DME(μ_3-Cl)(μ_2-Cl)_5(La·DME)Li(THF)_2晶体的结构分析表明，前者为单斜晶系，P21/C空间群。a=10.542(4), b=32.236(4), c=11.182(6)A °; β=113.50(3) °, V=3484.97 A °~3. Z=4, R=0.0471；后者为三斜晶系，PT空间群，晶胞参数是：a=11.123(3), b=16.564(5), c=8.653(3)A °;α=95.16(3), β=95.63(3), γ=74.71(3) °;V=1527.0A °~3。Z=2，R=0.0303。实验结果还表明，μ_2-和μ_3-氯桥键是LnCl_3-LiCl-THF类配合物中最基本、最重要的配位键，这种键是通过多重键的方式起着稳定分子结构的作用。当进行与有机配体的交换反应时，由于它们的特殊稳定性，能起到阻止轻稀土有机配合物歧化反应的作用。II环戊二烯基轻镧系氯化物的合成及其稳定性的研究对(G_5H_5)_3Ln·THF和LnCl_3·3LiCl-THF (Ln=La, Nd)溶液反应的研究表明，由于μ_2-氯桥键的作用，轻稀土环戊二烯基化合物中环戊二烯基的再分配反应，在0℃或室温下都能迅速进行。通过两者不同的摩尔比反应，经元素分析、红外光谱、~1H NMR和质谱鉴定，方便地合成了C_5H_5 LnCl_2·2LiCl·5THF和(C_5H_5)_2LnCl.LiCl·nTHF (Ln=La, Nd)等配合物。这一结果表明(C_5H_5)_2LnCl.LiCl·nTHF配合物不仅能稳定地存在于THF溶液中，而且能在一定条件下析出结晶。对(C_5H_5)_2LaCl.LiCl·4THF的晶体结构测定表明，该晶体属于正交晶系，Pc2m空间群。a=12.306(4), b=23.056(6), c=26.701(11)A°; V=7575.81A°~3;而(C_5H_5)_2LaCl·LiCl(DME)_2THF晶体则属于六方晶系，a=12.967(4), b=12.967(4), c=24.108(10)A°;V=3510 A°~3。通过(G_5H_5)_3Ln·THF与LnCl_3·3THF (Ln=La, Nd)的反应进一步研究了轻稀土环戊二烯基氯化物的稳定性。经元素分析，红外光谱和晶体结构分析表明合成了[(η~5-C_5H_5)_4La_3Cl_5·3THF]_2·9THF和(C_5H_5)_2 NdCl·THF配合物，前者属于三斜晶系，P1空间群。a=11.690(3), b=11.750(5), c=18.433(6)A°; α=98.75(3), β=95.62(3), γ=118.92(2)°; V=2147.06 A°~3. Z=1, R=0.099。对环戊二烯基轻稀土氯化物的稳定性进行了较详细地讨论。结果表明，THF的用量和化合物的溶解度是影响产物组成的决定因素。当THF的量不足以溶解所生成的产物时，就会歧化成溶解度最大((C_5H_5)_3Ln·THF)和最小(LnCl_3·nTHF)的两种组分。反之，环戊二烯基轻稀土化合物(Ln=La, Nd)中环戊二烯基的再分配反应就能顺利进行。经元素分析和结构测定，在((C_5H_5)_3Nd·THF)和NdCl_3·LiCl-THF溶液的反应体系中，偶然分离得到了[(η~5-C_5H_5)_4Nd_4(μ_4-o)(μ_2-Cl)_8] [Li(DMP)_2THF]_2这一不合常规的化合物，其晶体属于正交晶系，Pna2,空间群a=19.010(7), b=23.231(6), c=14.180(4); V=6261.91 A°~3。Z=4, R=0.054。说明在一定条件下,μ-氧桥键也起到了稳定分子结构的作用。推测了各类环戊二烯基轻稀土氯化物在THF中的合成反应机理,在LiCl存在的反应体系中Ln cl cl Li桥键能与环戊二烯基发生交换反应;在(C_5H_5)_3Ln·THF和LnCl_3·3THF的反应体系中,首先存在着LnCl_3分子之间的互相作用，因而易于形成双核或多核配合物。这类配合物以晶体形式析出时，易于发生结构上的变化，即化合物的结晶形态与溶液中的形态不一定相同。探索了环戊二烯基烯丙基稀土化合物新的合成方法。找到了真空加热脱水制备氯化稀土的最佳条件，其产物纯度在97%以上。通过加入Co_3O_4/Wo_3催化助燃剂的方法，提高了测定稀土有机化合物中碳含量的准确性。

西藏胡黄连和鸡矢藤的化学成分及黄芪多糖的提取工艺研究

本论文由四部分组成，前三部分为实验论文，第四部分为文献综述。第一、二部分分别报道了中药西藏胡黄连和鸡矢藤的化学成分研究结果。从两种药用植物中共分离和鉴定了32个化学成分，其中3个为新化合物。第三部分为黄芪多糖的提取工艺研究。第四部分概述了近年来植物多糖的研究进展。 第一章为西藏胡黄连化学成分研究。通过正、反相硅胶柱层析等分离方法从药用植物西藏胡黄连（Picrorhiza scrophulariiflora Pennell）的根茎中共分离纯化出7个化合物。运用MS、1H-NMR、13C-NMR、DEPT、HSQC和HMBC等现代谱学方法，结合理化分析对这些化合物的结构进行了分析鉴定。7个化合物中有两个是酚性的葡萄糖苷类成分：西藏胡黄连酚苷D (1)、4-O-β-D-(6-O-vanilloyl glucopyranosyl) vanillic acid (6)；四个苯乙基苷类化合物：plantamajoside (2)、plantainoside D (3)、西藏胡黄连苷A (4) 和西藏胡黄连苷F (5)；一个苯基小分子化合物：香豆酸甲酯 (7)。其中化合物1和5未见文献报道，确定为新化合物；化合物3为首次从该种植物中分到。 第二章为鸡矢藤化学成分研究。从鸡矢藤（Paederia scandense (Lour) Merrill）全草中分离出25个化合物，通过理化常数和波谱数据鉴定了它们的结构。25个化合物中包括一个蒽醌类成分：茜根定-1-甲醚 (1)；两个香豆素：异东莨菪香豆素 (2)和5-羟基-8-甲氧基吡喃香豆素 (3)；两个香豆素-木脂素化合物：臭矢菜素 B (4)和臭矢菜素 D (5)；一个木脂素：异落叶松树脂醇 (6)；两个黄酮：diadzein (7)和蒙花苷 (8)；三个三萜类化合物：齐墩果酸 (9)、乌苏酸 (10)和 3-O-β-D-吡喃葡萄糖基乌苏烷 (11)；三个甾体及其糖苷：b-谷甾醇 (12)、胡萝卜苷 (13)和(24R)-豆甾-4-烯-3-酮 (14)；六个小分子化合物：对羟基苯甲酸 (15)，咖啡酸 (16)，香豆酸 (17)，丁烯二酸 (18)，3,5-二甲氧基-4-羟基苯甲酸(19)，咖啡酸-4-O-β-D-吡喃葡萄糖苷(20)；五个环烯醚萜类化合物：鸡矢藤苷 (21)，鸡矢藤酸 (22)，鸡矢藤酸甲酯 (23)，saprosmoside E (24)和paederoside B (25)。其中化合物25未见文献报道，为新化合物。化合物1～8、11、14、15～20为首次从该化合物中分离得到。同时对鸡矢藤中环烯醚萜类化合物做了高效液相-串联质谱(HPLC-MSn)分析，探讨了这类化合物的质谱裂解规律。 第三章为黄芪多糖的提取工艺研究。首先确定了黄芪多糖含量的测定方法，并进行了方法学验证；其次探讨了黄芪中黄芪多糖的提取工艺，确定以酶法-Sevag法联用来去除黄芪多糖中的蛋白质，可使其提取物中黄芪多糖总含量达到70％以上。 第四章为近年来植物多糖的研究进展。主要包括植物多糖的提取纯化、多糖的定性定量检测方法、多糖的结构分析和多糖的药理活性。 This dissertation consists of four parts. The first and second parts reports the studies on the chemical constituents of medicinal plants of Picrorhiza Scrophulariiflora and Paederia scandens. The third part is about the extract technique of Astragalan Polysaccharide (APS). The last part reviews the progress of the studies on plant polysaccharides. 　 The first chapter is about the chemical constituents of P. Scrophulariiflora which is widely used as an important medicine to treat various immune-related diseases. A new phenyl glycoside, scrophenoside D (1) and a new phenylethyl glycoside, scroside F (5), together with five known compounds, plantamajoside (2), plantainoside D (3), scroside A (4), 4-O-β-D-(6-O-vanilloylglucopyranosyl) vanillic acid (6); and methyl-p-coumarate (7) were isolated from the stems of P. scrophulariiflora. Their structures were elucidated by spectroscopic and chemical methods. The second chapter is about the chemical constituents of medicinal herb of P. scandens. Twenty-five compounds were isolated and purified by normal and reversed phase silica gel column chromatography. By physicochemical properties and spectral analysis, their structures were identified as rubiadin-1-methylether (1), isoscopoletin (2), 5-hydroxyl-8-methoxyl-coumarin (3), cleomiscosin B (4), cleomiscosin D (5), isolariciresinol (6), diadzein (7), linarin (8), oleanolic acid (9), ursolic acid (10), 3-O-β-D-glucopyranosyloxyl-ursane (11), b-sitosterol (12), b-daucosterol (13), (24R)-stigmast-4-ene-3-one (14), p-hydroxyl-benzoic acid (15), caffic acid (16), coumaric acid (17), trans-butenedioic acid (18), 3,5-dimethoxyl-4-hydroxylbenzoic acid (19), caffeic acid 4-O-β-D-glucopyranoside (20), paederoside (21), paederosidic acid (22), paederosidic acid methyl ester (23), saprosmoside E (24), paederoside B (25). Among them, compound 25 is a new compound. Compounds 1～8、11、14、15～20 were isolated from this plant for the first time. Futhermore, we studied the HPLC-MSn analysis and investigation of fragmentation behavior of the sulfur-containing iridoid glucosides. The third chapter is about the extracting process of Astragalan Polysaccharide (APS). The method of the content determination is built. The optimum condition of extraction of polysaccharides from Radix Astragali is defined and the more effective way to remove protein is combined enzyme method with Sevag method, by which the content of polysaccharides extract can be up to 70%. The last part is a review of the research progress of the plant polysaccharides, which includes its extraction, isolation, purification, determination, structure analysis, and pharmacology.

奇异核的实验研究

总结了兰州放射性束实验小组在兰州放射性次级束流线上近几年来利用产生的放射性束流 ,轰击Si或C等靶子 ,测量它的反应总截面 .并利用经验公式将这些结果归一到相同的能量和靶子 ,与其相邻的核相比较 ,发现了9C ,11Be ,14 Be ,8B ,14 B和12 N等核素的反应总截面值有奇异增大的现象 .利用微观的Glauber模型进行了计算 ,对有奇异结构的核采用核芯加价核子的密度分布形式 ,理论计算和实验结果符合得很好 ,可以给出奇异核的弥散的密度分布 .

The Main Path to C, N, O Elements in Big Bang Nucleosynthesis

The production of C, N, O elements in a standard big bang nucleosynthesis scenario is investigated. Using the up-to-date data of nuclear reactions in BBN, in particular the Li-8 (n, gamma) Li-9 which has been measured in China Institute of Atomic Energy, a full nucleosynthesis network calculation of BBN is carried out. Our calculation results show that the abundance of C-12 is increased for an order of magnitude after addition of the reaction chain Li-8(n, gamma) Li-9(alpha, n) B-12(beta) C-12, which was neglected in previous studies. We find that this sequence provides the main channel to convert the light elements into C, N, O in standard BBN.

Synthesis, crystal structure, and thermal property of a novel supramolecular assembly: (NH42810424)(CHNO) O-[H(V)O(]2H)4(10)28(2), constructed from decavanadate and caffeine

A novel 3D supramolecular assembly constructed from decavanadate and caffeine building blocks, (NH4)(2)(C8H10N4O2)(4)[H4V10O28].2H(2)O (1), has been synthesized in aqueous solution and characterized by elemental analysis, IR, H-1 NMR, V-51 NMR, TG-DTA, and single crystal X-Ray diffraction. The compound 1 crystallizes in monoclinic system, space group P2(1)/n, a = 15.801(1) Angstrom, b = 12.914(1) Angstrom, c = 15.913(2) Angstrom, beta = 113.55degrees, V = 2976.4 (5) Angstrom(3), Z = 2, R = 0.0498 with 6818 reflections. Water molecules, ammonium ions, and caffeine act as "cement" linking the polyanions into 1D chain along the c-axis by hydrogen bonding. In compound 1, extensive hydrogen-bond contacts and strong pi-pi interactions lead to an ordered 3D supramolecular framework. TG-DTA curves indicate that the weight loss of the complex can be divided into three stages.

Synthesis, crystal structure, and magnetic properties of {[Cu(oxbe)]Mn(H2O)[Cu(oxbe)(DMF)]}(n)center dot nDMF center dot nH(2)O: From dissymmetrical mononuclear entities to a 3D heterometallic supramolecular coordination polymer

Self-assembly of the building block [Cu(oxbe)](-) with Mn(II) led to a novel coordination polymer {[Cu(oxbe)]Mn(H2O)(Cu(oxbe)(DMF)]}(n).nDMF.nH(2)O, where H(3)oxbe is a new dissymmetrical ligand N-benzoato-N'-(2-aminoethyl)-oxamido and DMF = dimethylformamide. The crystal forms in the triclinic system, space group P(1)over-bar, with a = 9.260(4) angstorm, b = 12.833(5) angstrom, c = 15.274(6) angstrom , alpha = 76.18(3)degrees, beta = 82.7(3)degrees, gamma = 82.31(3)degrees, and Z = 2. The crystal structure of the title complex reveals that the two-dimensional bimetallic layers are constructed of (CuMnII)-Mn-II-Cu-II chains linked together by carboxylate bridge and hydrogen bonds help to produce a novel three-dimensional channel-like structure. The magnetic susceptibility measurements (5-300 K) were analyzed by means of the Hamiltonian (H)over-cap = -2J(S)over-cap (Mn)((S)over-cap(Cu1) + (S)over-cap(Cu2)), leading to J = -17.4 cm(-1).

Synthesis and structural characterization of a new molecule-based complex constructed from dodecamolybdophosphoric acid and imidazole

A new compound, (CH5N2)(3)(PMo12O40CH4N23H2O)-C-.-H-. (1), was synthesized and structurally characterized by elemental analyses, IR spectra, UV spectra, NMR spectra and ESR spectra. This is, to our knowledge, the first example of an imidazole-polyoxometalate species. The compound was recrystallized from N,N-dimethylformamide (DMF), and then black block-like crystals of (C3H5N2)(4)((PMoMo11O40)-Mo-V-O-VI)(.)4C(3)H(7)NO(.) 2H(2)O (2), were obtained. It crystallizes in a triclinic space group P (1) over bar with n=12.423(3) Angstrom, b=12.666(3) Angstrom, c=13.341(3) Angstrom, alpha=70.56(3)degrees, beta=71.16(3)degrees, gamma=64.18(3)degrees, V= 1742.3(6) Angstrom(3), Z=1, R1 = 0.0585, wR2 = 0.1885. An X-ray crystallographic study showed that the crystal structure is constructed by electrostatic attractions and hydrogen bonds between a dodecamolybdophosphoric anion and an imidazole. The imidazole and DMF molecules occupy cavities in a polyoxometalate lattice ordered along a c-axis. The structure of (2) is similar to that of (1) from a comparison of both IR spectra and TGA Curves.

Synthesis and crystal structure of 3-methoxycarbonylethyltin tetrachlorides anion

The anion of MeO2CCH2CH2SnCl4 - was obtained by decomposing the yellow solution of MeO2CCH2CH2SnCl3.(2-OHC6H4CH=NC6H5) by standing for 15 days, which is the product of 3-methoxy-carbonylethyltin trichlorides with Schiff base (2-OHC6H4CH=NC6H5). The title compound was characterized by elemental analysis, IR. H-1 NMR,C-13 NMR and X-ray diffraction analysis. The crystal of the title compound belongs to orthorhombic system, space group P2cn, a=7.852(2), b=12.236(1),c=16.952(4)Adegrees, V=1628.7 Angstrom(3), Z=4, D-c=1.79g/cm(3) F(000)=860, mu=22.2cm(-1), R=0.0449, Rw=0.0382. The title compound exists as a discrete molecule, and the tin atom attains a distorted octahedral geometry via the coordination of intramolecular carbonyl oxygen and chloride ion. The coordination number of tin atom is 6.

3-(四氯化锡)-丙酸甲酯阴离子的合成及晶体结构

在用酯基锡MeO2CCH2CH2SnCl3合成配合物MeO2CCH2CH2SnCl3·(2-OHC6H4CH=NC6H5)时,其配合物的甲苯溶液放置培养单晶时(放置十天以上)会发生分解生成配合物MeO2CCH2CH2SnCl4—·H+。研究了标题化合物的合成反应,用元素分析、IR、NMR对配合物进行了表征,并测定了晶体结构。为正交晶系,空间群为P2cn, a=7.852(2), b=12.236(1), c=16.952(4) ? V=1628.7?, Z=4, Dc=1.79g/cm3, F(000)= 860,m=22.2cm—1(Mo),R=0.0449, Rw=0.0382。标题化合物的空间构型为畸变的八面体构型,中心锡原子的配位数为6。

Synthesis of bis [bis (tert-butylcyclopentadienyl) neodymium chloride] and structural trend of bis[bis(tertbutylcyclopentadienyl) lanthanide chloride]

The reaction of NdCl3 with 2 equiv. of Na-(BuC5H4)-C-t in THF(tetrahydrofuran) gives blue crystals [((BUC5H4)-C-t)(2)NdCl](2), C36H52Cl2Nd2(M-r = 844.11) Which crystallizes in the triclinic system with space group . The crystal data are a=11.978 (1), b=12.671(4), c=12.706(2)Angstrom, alpha=105.47(2), beta=99.38(1)? gamma=93.15 (2)degrees, V=1825 (3) Angstrom(3), Z = 2 , D-c = 1.53g/cm(3), F(000) = 450 , T = 298K , lambda(MoK alpha) = 0.71069 Angstrom, , mu = 14.97cm(-1). Final R = 0.0390, R-w = 0.0376 for 4329 reflections with I greater than or equal to 3 sigma(I-o). The molecule has a dimer structure with two certrosymmetrical chlorine bridges. The structural trend of these analogous complexes is discussed.

Hydrothermal synthesis and crystal structure of sandwich-like heteropolymolybdophosphates

Sandwich-like heteropoly molybdochromophosphates of supermolecular compound [NH3(CH2)(6)NH3](2)H-3{Cr[Mo6O15(HPO4)(H2PO4)(3)](2)}. 4H(2)O has been hydrothermally synthesized and the single crystal structure has been determined by X-ray diffraction. The crystal data are has follows: triclinic, space group P (1) over bar a=12.156(2), b=12.809(3), c=13.530(3) Angstrom, alpha=102.46(3)degrees, beta=93.67(3)degrees, gamma=93.46(3)degrees, V=2046.9(7) Angstrom(3), Z=1, M-r=2768.69, D-c=2.246 g/cm(-3), F(000)=1337, mu=2.162 mm(-1). The structure has been refined to R=0.0666 and wR=0.1745 by full-matrix least-squares method. The title compound is composed of 1, 6-diaminohexane, water molecules, and {Cr[Mo6O15(HPO4)(H2PO4)(3)](2)}(7-) anion which consists of six oxygen atoms from two [Mo6P4] units with a sandwich-like transition metal atom Cr located at the center of symmetry.

Synthesis and crystal structure of a polymeric erbium(III)-sodium(I) coordination complex of picolinic acid N-oxide

A new Er(III)-Na(I) coordination polymer of stoichiometry [NaEr2L5(H2O)(6)(NO3)](NO3). 3.5H(2)O (HL = picolinic acid N-oxide) has been synthesized and characterized by single-crystal X-ray analysis. Crystals are triclinic, P (1) over bar with a = 9.823(2), b = 12.453(2), c = 20.643(4) Angstrom; alpha = 98.49(3), beta = 101.40(3), gamma = 108.69(3)degrees; V = 2284(1) Angstrom(3); Z = 2. Of the two independent eight-coordinate erbium(III) ions in this complex, one is surrounded by four bidentate chelating L ligands, and the other by one bidentate chelating L ligand, four aqua ligands and two anti-carboxylate oxygen atoms from two neighboring [ErL4] units. The sodium(I) ion is in a distorted octahedral environment, being coordinated by a unidentate nitrate anion, three aqua ligands and two anti-carboxylate oxygen atoms from two adjacent [ErL4] units. The complex is built from zigzag chains of syn-anti carboxylate-bridged erbium(III) moieties directed in the a direction, which are cross-linked pairwise by aqua-bridged dimeric sodium(I) units. The resulting composite polymeric chains are further connected by hydrogen bonds to form a three-dimensional network.