一例含有八核钴簇的锗钨酸盐的合成、结构及性质

以K_8Na_2[A-α-Ge W_9O_(34)]·25H_2O,Co(NO_3)_2·6H_2O和K_2CO_3等为原料,利用常规水溶液法合成了一例基于三缺位Keggin型多金属氧簇{Ge W_9O_(34)}的高核过渡金属衍生物K_(10.5)Cs_4H_(1.5){[Co_8(OH)_6(H_2O)_2](CO_3)_3(Ge W_9O_(34))_2}·12H_2O(1),并通过红外光谱、元素分析、热重分析和X射线单晶衍射等分析手段对其进行了表征。化合物1含有一个V型的多酸阴离子簇{[Co_8(OH)_6(H_2O)_2](CO_3)_3(Ge W_9O_(34))_2}~(16-),该阴离子进一步通过K~+和Cs~+离子连接形成二维结构。磁学性质研究表明,化合物1中Co~(2+)离子之间主要为反铁磁性耦合。     

Combination of Lindqvist-type Tungstovanadates and Transition Metal Clusters under Hydrothermal Conditions

<正>Two novel organic-inorganic heteropolyoxometalate compounds [{Cu(1,10- phen)OH}_2]_2[V_2W_4O_19]·6H_2O (1) and [Co(1,10-phen)_3]_2[V_2W_4O_(19)]·5H_2O (2) (1,10-phen = 1,10- phenanthroline) were hydrothermally synthesized and characterized by elemental analysis, IR spectra and single-crystal X-ray diffraction. Compound 1 contains a di-V substituted classical Lindqvist-type polyanion [V_2W_4O_(19)]~(4-), two dinuclear copper cations [{Cu(1,10-phen)OH}_2]~(2+) and six water molecules of crystallization. Two dinuclear copper cations [{Cu(1,10-phen)OH}_2]~(2+) consist of four transition metal coordination cations {Cu(1,10-phen)}~(2+), bridged by four hydroxyl groups. Meanwhile, both two dinuclear cations are grafted on the Lindqvist polyanion [V_2W_4O_(19)]~(4-) through two terminal oxygen (O(9)) and two μ_2-oxygen (O(6)) atoms. Such an unusual linking fashion is unique in the polyoxometalate chemistry. The basic framework of 2 is similar to that of 1 and contains one Lindqvist-type polyanion [V_2W_4O_(19)]~(4-), two six-coordinated cobalt cations [Co(1,10-phen)_3]~(2+) and five free water molecules.     

由双帽Keggin型簇和钴配合物构筑而成的结构新颖的聚合物（英文）

利用水热合成法得到了有机-无机杂化的钴钼钒簇[Co(en)_2]_4H_4{Co(phen)_2(H_2O)]_2[Mo_9~(VI)V_6~(IV)O_(42)]}[Mo_9~(VI)V_6~(IV)O_(44)]·12H_2O(phen=1,10-邻菲罗啉,en=乙二胺),用元素分析、红外光谱、热分析、磁分析和单晶衍射对该化合物做了表征.该化合物的分子结构单元是由双帽Keggin型多阴离子[Mo_9~(VI)V_6~(IV)O_(42)]~(6-)(简称1)、类似结构的多阴离子[Mo_9~(VI)V_6~(IV)O_(44)]~(10-)(简称2)、过渡金属配合物(两个[Co(phen)_2(H_2O)]~(2+)阳离子和四个[Co(en)_2]~(2+)阳离子)、四个质子和十二个结晶水分子组成.     

基于[P_2W_(17)O_(61)]~(10-)构筑的一维双链稀土衍生物的结构、合成及表征

饱和Dawson型[P_2W_(18)O_(62)]~(6-)(简称为[P_2W_(18)])多酸阴离子以其稳定的化学性质、良好的结晶性能成为多酸化学领域中的重要研究对象.本文以K_6[α-P_2W_(18)O_(62)]·xH_2O、Ce(NO_3)_3·6H_2O为基本原料,通过常规水溶液加热回流法,成功地合成了一例结构单元类似2∶17型Dawson-稀土双系列结构的一维双链化合物{[Na_2[N(CH_3)_4]_8[Ce(CH_3COO)(H_2O)]_2[Ce(H_2O)_7](P_2W_(17)O_(61))]_2·23H_2O}_n(1).结构分析表明,化合物1属于三斜晶系,P-1空间群,晶胞参数为:a=1.327 97(15)nm,b=1.376 71(15)nm,c=3.121 1(3)nm.该化合物以单缺位[P_2W_(17)O_(61)]~(10-)(简称为[P_2W_(17)])为基本构筑单元,中心原子Ce不仅与[P_2W_(17)]通过氧桥直接相连,而且通过醋酸根与另外一个Ce-[P_2W_(17)]单元相连,并最终形成新颖的一维双链结构.此外,我们还通过红外光谱、元素分析、热失重分析、紫外-可见吸收光谱分析等方法,对化合物1进行了较全面的表征.     

一例基于Keggin型多酸阴离子的双加帽杂多铌酸盐的合成、结构及表征

在水热条件下,成功合成了一例基于Keggin型多酸阴离子的双加帽杂多铌酸盐[Ni(en)_3]_3[Ni(en)_2(H_2O)_2]_2H[VNb_(12)O_(40)(VO)_2]·10H_2O(1),并通过红外光谱、热重分析和X射线单晶衍射等方法对该化合物进行了表征.X射线单晶衍射分析表明,化合物1属于正交晶系,Pna2(1)空间群,晶胞参数a=3.051 7(3)nm,b=1.561 0(1)nm,c=2.271 9(3)nm,V=10.823(3)nm~3.化合物1包含1个Keggin型聚阴离子[VNb_(12)O_(40)(VO)_2]~(11-)和3个镍配离子.在阴离子结构中,中心钒原子被12个铌原子包围形成经典Keggin型结构的[VNb_(12)O_(40)]~(15-)阴离子,另外两个{VO}基团分别加帽于[VNb_(12)O_(40)]~(15-)阴离子的两端.     

基于自组装生成[Bi_2W_(21)O_(70)(OH)_3]~(11-)配体的双核Ce(Ⅳ)配合物合成、结构及电化学性质

使用[β-B-BiW_9O_(33)]~(9-)作为基本建筑单元,成功合成了多酸做配体的双核Ce(Ⅳ)配合物(Na_6H_(10){Ce(H_2O)_3(μ_2-OH)[Bi_2W_(21)O_(70)(OH)_3]}_2·40H_2O),通过元素分析、X-射线单晶衍射、XRD、IR和TG表征技术确定了其组成和结构.两核Ce(Ⅳ)离子配合物是通过2个μ_2-OH~-连接构成的,每个Ce(Ⅳ)离子除了与2个μ_2-OH~-配位外,还与3个H_2O以及[Bi_2W_(21)O_(70)(OH)_3]~(11-)中4个缺位O原子配位,形成三帽三棱柱.[Bi_2W_(21)O_(70)(OH)_3]~(11-)多酸阴离子是通过3个W(Ⅵ)连接形成新的多酸阴离子物种,在缺位结构上留有一个空位恰好与Ce(Ⅳ)离子配位.通过对配合物的电化学分析发现,与硝酸铈铵对比,配合物中Ce(Ⅳ/Ⅲ)的阳极峰电势由0.857减小至0.772V,表明多酸阴离子配体有稳定Ce(Ⅳ)的作用.     

一种硒桥连的四核锰取代的类Dawson硒钨酸盐

在水溶液中合成了一种新型硒桥连的四核锰取代的类Dawson硒钨酸盐[H_2N(CH_3)_2]_4 KH_7[Mn_4(H_2O)_6(SeO)_2(Se_2W_(12)O_(46))_2]·45H_2O (1),并通过红外光谱,热重分析和X射线单晶衍射对其结构进行了表征.1中二聚的[Mn_4(H_2O)_6(SeO)_2(Se_2W_(12)O_(46))_2]~(12-)阴离子由两个六缺位类Dawson的[Se_2W_(12)O_(46)]~(12-)片段通过两个[Mn(H_2O)_2(SeO)]~(4+)和两个[Mn(H_2O)_2]~(2+)离子连接而成.值得注意的是两种不同配位方式的锰原子在连接两个[Se_2W_(12)O_(46)]~(12-)片段时发挥着重要的作用.一类Mn~(2+)离子和Se~(4+)离子结合作为桥占据[Se_2W_(12)O_(46)]~(12-)片段的"极位",另一类Mn~(2+)离子占据了"赤道位".此外,对其磁性进行了研究.     

有机-无机杂化的钼砷酸盐的水热合成和性质

通过水热法合成了由As-Mo-O簇和Cu~I有机单元构筑而成的钼砷酸盐{[Cu~I(2, 2′-bipy)_2]_3[As(OH)Mo_4O_(14)(OH)]·2H_2O}_(2 )(1)(bipy=bipyridine),并用元素分析、红外光谱和X射线单晶衍射对其进行了定性.1属于单斜晶系,P2(1)/c空间群.1中的多阴离子[As(OH)Mo_4O_(14)(OH)]~(3-)是有四个交替的共面的和共边的{MoO_6}八面体组成,在这些八面体上有一个{AsO_2(OH)}单元.     

九钨三锰硅酸钾异构体的合成及其转移氧原子的性质

Hill~[1],Finke~[2]和Neumann~[3]曾分别报道[Pw_(11)O_(39)M]~(n-)、[P_2W_(17)O_(61)M]~(n-)和[SiW_(11)O_(39)Ru]~(5-)具有催化烯烃环氧化反应的性质,三取代的Keggin杂多阴离子有相似的性质.本文首次报道α-和β-K_6H_4[SiW_9O_(37)Mn_3(H_2O)_3]·xH_2O的合成及其转移氧原子的性质,为研究杂多酸盐的催化提供了一个新的含锰杂多阴离子.     

A New 1-D Organic-inorganic Hybrid Polyoxotungstate Constructed from Sandwich-type Polyanions and Copper~Ⅱ-organoamine Complexes

A new organic-inorganic hybrid sandwich-type polyoxotungstate [Cu(dien)-(H_2O)_2]_2[{Cu(dien)(H_2O)}_3{Cu_(4.5)W_(0.5)(B-α-Sb W_9O_(33))_2}](OH)4·7H_2O(1, dien = diethylenetriamine) has been hydrothermally synthesized and structurally characterized by elemental analyses, IR spectroscopy, TG analysis, and single-crystal X-ray diffraction analysis. Crystal data for 1: monoclinic, C2/c, a = 31.527(3), b = 13.9309(13), c = 24.297(2) ?, β = 1108.269(2)o, V = 10133.2(17) ?3, Dc = 4.024 g/cm3 and Z = 4. X-ray crystallographic study shows that the molecular structure of 1contains an infrequent penta-nuclearity {Cu4.5W0.5} cluster sandwiched polyanion [{Cu4.5W0.5(B-α-Sb W9O33)2}]6-, on which three [Cu(dien)(H_2O)]~(2+) complexes decorated as pendants. Interestingly, two [Cu(dien)(H_2O)]2+ pendants linked the two neighboring sandwich-type polyanions via double Cu-μ_2-O-W bridges, resulting in a 1-D chain. The magnetic measurements show compound 1exhibits obvious antiferromagnetic interactions.     

炔雌醚-6-酮-(O-羧甲基)肟和炔雌醇-6-酮-(O-羧甲基)肟的合成

为了研究长效口服避孕药复方炔雌醚的作用机理,我们采用放射免疫测定法,测定服药者血中炔雌醚(17α-乙炔雌二醇-3-环戊醚)及其代谢产物炔雌醇(17α-乙炔雌二醇)的浓度,以观察它们的动态变化规律.甾体化合物的分子量较小,本身没有抗原性,所以须先制备半抗原,然后再与大分子载体,如牛血清白蛋白结合,方能使动物免疫而产生抗血清.目前甾体雌激素的半抗原多采用6-(O-羧甲基)肟衍生物.通常先用铬酐-乙酸氧化雌激素,引入6-酮基,再制成肟衍生物.但是铬酐-乙酸的氧化产物甚为复杂,得率亦低.     

Facile Syntheses of (6S)-6-Fluoroshikimic Acid and (6R)-6-Hydroxyshikimic Acid

ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｓｈｉｋｉｍａｔｅｐａｔｈｗａｙｉｓａｎｉｍｐｏｒｔａｎｔｂｉｏｓｙｎ ｔｈｅｔｉｃｓｅｑｕｅｎｃｅｉｎ ｐｌａｎｔｓ ,ｆｕｎｇｉａｎｄｍｉｃｒｏｏｒｇａｎｉｓｍｓｆｏｒｔｈｅｃｏｎｖｅｒｓｉｏｎｏｆｃａｒｂｏｈｙｄｒａｔｅｓｔｏｔｈｅａｒｏｍａｔｉｃａｍｉｎｏａｃｉｄｓ (Ｌ ｐｈｅｎｙｌａｌａｎｉｎｅ ,Ｌ ｔｙｒｏｓｉｎｅａｎｄＬ ｔｒｙｐｔｏｐｈａｎ)ａｎｄｐｒｅｃｕｒｓｏｒｓｔｏｔｈｅｆｏｌａｔｅｃｏｅｎｚｙｍｅｓ ,ａｌｋａｌｏｉｄｓａｎｄｖｉｔａｍｉｎｓ[1] .Ａｓ…     

P6（D6h）和P12（D6h的从头算研究

利用Ｇａｕｓｓｉａｎ－９２从头算程序，在６－３１Ｇ￣＊基组下优化Ｐ_６（Ｄ_６ｈ）分子和Ｐ_（１２）（Ｄ_（６ｈ））原子簇，并进行了振动频率的计算．得到２Ｐ_６（Ｄ_（６ｈ））→Ｐ_（１２）（Ｄ_（６ｈ））总能量的相对值，即△Ｅ＝Ｅ_Ｐ_（１２_（Ｄ_（６ｈ））－２ＥＰ_６（Ｄ_（６ｈ））＝－１．１９７ｅＶ．　Ｐ_（１２）（Ｄ_（６ｈ））原子簇较２Ｐ_６（Ｄ_（６ｈ））分子在热力学上更为稳定。基组下，Ｈｐ＝ＨＰ优化的Ｐ＝Ｐ双键键长为０．２００５ｎｍ，Ｈ２Ｐ─ＰＨ２优化的Ｐ─Ｐ单键键长为０．２２１４ｎｍ，显然，Ｐ６（Ｄ６ｈ）分子中的键长比优化双键长０．００９１ｎｍ，比优化单键短０．０１１８ｎｍ，对于Ｐ６（Ｄ６ｈ）分子而言，其键长介于单、双键之间且相等。Ｐ６分子前线轨道的第３９条分子轨道形式估算为：联系人及第一作者：冯健男，男，２５岁，博士研究生。     

6-Azauracilribosid (6-Azur) in Blutserum

Ohne Zusammenfassung     

Reassessment of the electronic absorption spectra of Cr(η6-C6H6)2, Cr(CO)6 and Cr(η6-C6H6)(CO)3

The UV absorption bands between approximately 330 and 200 nm have been assigned to Rydberg transitions for the d⁶ complexes Cr(η⁶-C₆H₆)₂, Cr(CO)₆ and Cr(η⁶-C₆H₆)(CO)₃     

Experimental and theoretical evidence for U(C6H6) and Th(C6H6) complexes

The vibrational spectra of UBz and ThBz have been measured in solid argon. Complementary quantum chemical calculations have allowed the assignments of the vibrational spectra. According to the calculations, AcBz are stable molecules, as well as other species like BzAcBz and BzAc2Bz. Experimentally, there is no evidence for the sandwich compounds BzAcBz and BzAc2Bz due to the limitations in the reagent concentrations.     

Stereocontrolled synthesis of (5+5), (5+6) and (6+6) 3-spiropseudonucleosides

3-Spiropseudonucleosides, in which the heterocyclic base is a five-membered (oxazolidine, imidazolidine, thiohydantoin) or six-membered (perhydrooxazine) heterocycle, have been prepared starting from a hexofuranos-3-ulose. The method leads to good yields and is completely stereoselective. The key intermediate is a sugar iso(thio)cyanate.     

The S(6) Point Group Conformers of the Hexamethylchalcogens: Me(6)S, Me(6)Se, Me(6)Te

The synthesis of Me(6)Te in 1990 stimulated the exploration of hexamethylchalcogen potential energy surfaces. This earlier ab initio work focused only on the D(3) conformers, but it has been noted that the pseudooctahedral X(CH(3))(6) compounds show either D(3) or S(6) symmetry. Here are reported the results of an ab initio molecular orbital study of the hexamethylchalcogens confined to S(6) symmetry. Stationary points were found for each of the three hexamethylchalcogens studied and were shown to be minima for the two larger hexamethylchalcogens. Each of the S(6) stationary points found was energetically higher lying than the earlier reported D(3) counterpart. These energy differences are discussed in terms of nuclear repulsion and molecular orbital bonding considerations.     

Low-dimensional hybrid copper halides with novel D6R Cu(6)I(6) cores

Two low-dimensional hybrid copper halides, (2,2'-bipy)Cu(3)I(3) (1) and (2,2'-bipy)Cu(4)I(4) (2) (2,2'-bipy = 2,2'-bipyridine), with novel D6R (double six-membered rings) Cu(6)I(6) cores were synthesized by hydro(solvo)thermal reactions and characterized by single-crystal X-ray diffraction.