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1.
The reaction of AgNO3 with [(“Bu4N2 i-MNT)]3 in CH3CN produces a new silver cluster anion [Ag4(i-MNT)4]4? ,3, a species having a tetrahedral arrangement of silver atoms bridged by fouri-MNT ligands which has been isolated and characterized by X-ray crystallography as [Bu4N]2[(PPh3)2]2 [Ag4(i-MNT)4],4. The reaction of two or three equivalents of Ag(PPh3)2NO3 with [BzEt3N]6[Ag6(i-MNT)6] in CH3CN produces two new clusters, [BzEt3N]4[Ag8(i-MNT)6(PPh3)4],6, and [BzEt3N]3[Ag4(i-MNT)6(PPh3)6], 7, having the common structural feature of an octahedral Ag6S12 core. The octanuclear Ag8 cluster also can be synthesized from the reaction of 4 and PPh3 in CH2Ck2 and compound 5 has been structurally characterized as [Bu4N]2[(PPh3)2N]2[Ag8(i-MNT)6(PPh3)4]. The31P{1H} NMR spectrum of 6 in CD3CN at ?43° shows two sets of two doublets. The corresponding chemical shift and coupling constant of each species is 9.32 ppm (354, 408.8 Hz) and 9.45 ppm (346.7, 401.7 Hz), respectively. Pertinent crystallographic data are as follows: Compound 4 crystallizes in the orthorhombic space group Cc2a, witha=18.668(3)A,b=36.793(4) A,c=17.836(3)A, Z=4, andV= 12250(3)A3. Compound 5 crystallizes in the triclinic space group P1, witha=16.506(3)A,b=17.280(3)A,c=19.144(4) A,x=98.485(14)°, β= 105.44(2)°.y=94.63(2),Z= 1, andV = 5164(2)A3. Compound6 crystallizes in the monoclinic space group C2/m, witha= 25.341(9)A,b= 25.289(9)A,c= 15.076(7)A, β= 107.19(5)°,Z=2, and V=9230(6)A3. Compound7 crystallizes in the monoclinic space group C2/c, witha=25.872(6)A,b=21.288(4) A,c=35,928(5), β=100.98(1)°,Z-4, andV=19426(6)A3.  相似文献   

2.
章慧 《大学化学》1996,11(2):49-52
结合对[Co(NH3)5Cl]^2)与[Co(NH3)6]^3+的颜色的比较,阐述配体场理论中有关电子组态、能级、轨道、配体场谱项及谱项间跃迁等基本概念及难点。即使不做严格的量子化学计算,从直观的物理模型、简单的分子轨道理论、群论方法及有关谱图中也能获得有用信息。  相似文献   

3.
The salts [RuII(L–L)3](CF3SO3)2 (L–L = bpy or phen) have been prepared in high yields via reactions of [RuII(DMF)6](CF3SO3)2 (DMF = N,N-dimethylformamide), generated in situ by reduction of [RuIII(DMF)6]-(CF3SO3)3, with an excess of bpy or phen at room temperature in DMF solutions.  相似文献   

4.
Complexes with antimony-containing anions, [Ph3MeP] + 2 [SbI5]2? (I), [Ph3MeP] + 2 [Sb3I12]3? (II), [Ph3MeP] + 3 [Sb3I12]3? · Me2C=O (III), and [Ph3MeP] + 3 [Sb2I9]3? (IV), were synthesized by reacting triphenylmethylphosphonium iodide with antimony iodide. The central atom in the cations of the complexes has a distorted tetrahedral coordination. In the trinuclear anions of complexes II and III, each of the terminal SbI3 groups is bound to the central Sb atom through two μ2- and one μ3 iodine bridges (SbSbSb angles are 103.0° and 102.2°, respectively). In the binuclear anion of complex IV, antimony atoms are linked with each other via three bridging iodine atoms.  相似文献   

5.
The unimolecular dissociation reactions of doubly charged ions were reported,which resulted from a tandem mass spectrometer and a reversed geometry double focusing mass spectrometer by electron impact.Mass analyzed ion kinetic energy spectrometry(MIKES) was used to obtain the kinetic energy releases in charge separation reactions of doubly charged ions.The intercharge distances between the two charges at transition states can be calculated from the kinetic energy releases.Transition structures of unimolecular dissociation reactions were infered from MIKES and MS/MS.  相似文献   

6.
银氨溶液中的溶质是[Ag(NH3)2]OH吗   总被引:2,自引:1,他引:1  
杨洪雷 《化学教育》2008,29(6):67-68
先从理论上证明了教材中所给的配制方法配制出来的银氨溶液中的溶质不是[Ag(NH3)2]OH而是[Ag(NH3)2]NO3,然后又利用对照实验对这一结论进行了实验验证。  相似文献   

7.
The oxidation of the [Fe(CO)4]2– dianion with Ag+ salts occurs through a particularinner-sphere mechanism, which involves an intermediate cascade of silver clusters stabilized by Fe(CO)4 ligands. The last detectable Ag-Fe cluster of the sequence is the [Ag13{-Fe(CO)4}8]3– trianion, which has been selectively obtained by using ca. 1.7 equivalents of Ag+ per mole of [Fe(CO)4]2–. The [Ag13{-Fe(CO)4}8]3–- trianion has been isolated in a crystalline state with several quaternary cations, and has been characterized by X-ray diffraction studies of its bis(triphenylphosphine)iminium salt. [N(PPh3)2]3 [Ag13{ 3-Fe(CO)4}8]·2(CH3)2CO, monoclinic, space group P21 (No.4),a = 16.284(2) Å,b =18.767(5) Å,c = 25.905(4) Å, = 90.46(1)°,V = 7916(3) Å3,Z = 2,R = 0.0324. The molecular structure of the anion consists of a centered cuboctahedron of silver atoms with the triangular faces capped by Fe(CO)4 units. Chemical reduction of ( Ag13{ 3-Fe(CO)4}8]3– affords the corresponding [Ag13{ 3-Fe(CO)4)8]4–, which in turn gives [Ag13{ 3-Fe(CO)4)8]5– and [Ag6{ 3-Fe(CO)4}4] upon further reduction. Electrochemical investigations confirm the reversibility of the [Ag13{ 3-Fe(CO)4}8]3–/4– redox change. Furthermore, in spite of some electrode poisoning effects, evidence of the existence of the [Ag13{ 3-Fe(CO)4}8]5– pentaanion was obtained. The yet structurally uncharacterized [Ag6{ 3-Fe(CO)4)4]2– dianion is quantitatively obtained by reaction of [Fe(CO)4]2– with ca. 1.5 equivalents of Ag+ or by addition of one equivalent of Ag+ to solutions of the [Ag5{Fe(CO)4}4]3– trianion. All attempts to isolate its quaternary salts as crystalline materials failed owing to formation of amorphous insoluble precipitates. The above series of 3-Fe(CO)4 octa-capped cuboctahedral Ag13 clusters can be envisioned as the Ag+ . Ag and Ag cryptates of the [Ag12{}3-Fe(CO)4}8]4– cryptand. respectively.Dedicated to Prof L. F. Dahl on his 65th birthday.  相似文献   

8.
在碱性介质中只有少数氧化剂如Ag(Ⅲ)及Cu(Ⅲ)仍有较强的氧化性,因此研究Ag(Ⅲ)、Cu(Ⅲ)络合物阴极还原的电极电势、电子转移数及还原机理,对于深入了解它们作为氧化剂时的氧化还原特性是有帮助的.本文用薄层光谱电化学方法测定了二过碘酸合银(Ⅲ)、络离子在不同pH条件下还原反应的E~0′和电子转移数(n),并由此推断阴极还原反应机理,还用同样方法研究了二过碘酸含铜(Ⅲ)络离子的阴极还原.  相似文献   

9.
Zusammenfassung Die Absorptions- und Reflexionsspektren der Oktocyanokomplexe desMo(IV) undW(IV) sowie die Absorptionsspektren der Oktocyanotomplexe desMo(V) undW(V) werden mitgeteilt. Die Spektren werden unter Zugrundelegung der durch Raman- und IR-spektroskopische Untersuchungen gefordertenD 4d-Symmetrie dieser Verbindungen interpretiert. Die beobachteten Banden niedriger Intensität (log<3) werden Übergängen in einem Termsystem zugeordnet, das für die Konfigurationend 2 undd 1 und die SymmetrieD 4d berechnet worden ist. Banden hoher Intensität (log>3) werden auf Übergänge in antibindende Zustände zurückgeführt, an denen höherep-Zustände des Zentralions sowie Ligandenzustände beteiligt sind. Die erhaltenen Werte des Feldparameters stimmen mit ligandenfeldtheoretischen Erwartungen überein.
Absorption and reflection spectra of the octacyanides ofMo(IV) andW(IV) and the absorption spectra of the octacyanides ofMo(V) andW(V) are presented. The spectra are interpreted in terms of theD 4d symmetry of the compounds supported by investigations of Raman and infrared spectra. Bands of low intensity (log<3) correspond to transitions between levels obtained in the case of the configurationsd 2 andd 1 respectively, in a field ofD 4d symmetry. Bands of high intensity (log>3) are attributed to transitions into antibonding levels in which p-orbitals of the central ion and ligand orbitals participate. The values of the field parameter obtained are in accord with ligand field theory.

Résumé Les spectres d'absorption et de réflexion des complexes octocyanurés duMo(IV) et duW(IV) ainsi que les spectres d'absorption des mêmes complexes deMo(V) et de W(V) sont présentés. Les spectres sont interprétés en supposant la symétrieD 4d des molécules indiquée par des analyses des spectres Raman et infrarouges. Les bandes de faible intensité (log<3) sont attribuées à des transitions dans un système de niveaux, calculé pour les configurationsd 2 etd 1, respectivement, en symétrieD 4d. Des bandes de forte intensité (log>3) sont attribuées à des transitions vers des niveaux antiliants auxquels participent des fonctions élevéesp de l'ion central et des fonctions des groupes liés. Les valeurs obtenues pour le paramètre de champ sont en accord avec les prévisions de la théorie.
  相似文献   

10.
银硫二元团簇[Ag·(Ag2S)n] +(n=1,2)的从头算研究   总被引:7,自引:3,他引:4  
用abinitio分子轨道限制和密度泛函方法对团簇「Ag.(Ag2S)n」^+(n=1,2)的各种可能的几何构型分别进行了全优化,得到其稳定的几何构型和电子结构,并对这两种团簇可为硫敏化中主自由电子深陷阱的存在形式作出合理解释。  相似文献   

11.
采用共模板法以二乙胺和1,2-丙二胺为模板剂,合成了过渡金属取代的二维层状磷酸铝化合物[C4H11N]0.77[C4H1 2N]0.23[C3H12N2]2[Co0.2 3Al5.77P8O32][H3O]2(1).通过X射线衍射(XRD)、热重分析(TG)、元素分析(ICP-AES及CHN)、固体紫外-可见分析(Solid-UV-Vis)及扫描电子显微镜(SEM)等对化合物1进行了表征.该化合物属三斜晶系,P 1-空间群,晶胞参数a=0.95029(19)nm,b=1.2689(3)nm,c=1.2987(3)nm,α=118.70(3)°,β=97.64(3)°,γ=99.72(3)°,V=1.3117(5)nm3,Z=1.其无机骨架由铝(或钴)氧四面体(AlO4或CoO4)和磷氧四面体PO3(O)严格交替连接形成4,6,12-网层结构,无机层沿[001]方向堆砌成一维十二元环孔道.Co无序取代Al的位置,其Co/Al摩尔比约为1∶25.1.运用分子动力学模拟的方法,通过计算有机模板剂和无机骨架的相互作用,讨论了2种有机胺分子的共模板作用.  相似文献   

12.
The dianion [Ru10C(CO)24]2− in CH2Cl2 reacts with CO under ambient conditions to produce quantitative amounts of the species [Ru3(CO)12] and [Ru6C(CO)16]2−; the hydrido-anion [HRu10C(CO)24] reacts similarly to form [Ru6C(CO)16].  相似文献   

13.
《Polyhedron》1999,18(26):3533-3544
[Tris(1,3-dithiole-2-thione-4,5-dithiolato)stannate]2−, [Q]2[Sn(C3S5)3], [tris(1,3-dithiole-2-one-4,5-dithiolato)stannate]2−, [Q]2[Sn(C3S4O)3], and [tris(1,3-dithiole-2-thione-4,5-diselenolato)stannate]2− [Q]2[Sn(C3S3Se2)3], complexes, have been synthesised and characterised. Crystal structure determinations of [Q]2[Sn(C3S5)3] (Q=1,4-dimethylpyridinium, monoclinic and orthorhombic forms; NMe4, NEt4, and PPh4) and [NEt4]2[Sn(C3S4O)3] revealed variations in the overall dianion structures. The geometry about tin in each case is essentially octahedral with the chelate bite angles in the range 80.7(5)–87.45(4)°: the range of Sn–S distances is 2.5207(18)–2.571(17) Å. A statistical analysis, carried out on the crystal structure data for the six complexes, indicated that the most critical factors in controlling the overall shape of the dianion were the distances of the Sn atom from the dithiolate ligand planes [Sn–OOP]. Interanionic S⋯S interactions, within the sum of the van der Waals’ radii for two S atoms, are affected by the size of the cation, Q; the secondary connectivity is 3-dimensional for the smallest cations, Q=1,4-dimethylpyridinium and NMe4, in chains for the somewhat larger cation, NEt4 and is absent for the still larger, PPh4 cation.  相似文献   

14.
吴丹  许美羡  林深 《应用化学》2006,23(9):1000-1005
Waugh结构的H12[MnMo9O32(KO)6]的合成、晶体结构及催化性能;多金属氧酸盐;晶体结构;催化活性;Waugh结构  相似文献   

15.
A new polynuclear silver complex with bridging diphorsphine ligand has been synthesized and characterized by :single cryatsl X-ray diffraction method The compound crystallizes in the triclinic space group P1 with a=1.27489, b=1.34715, c=1.47015 nm; α=59.747, β=63.949, γ=70.196°; V=1.9369 nm. The simplest formularis [Ag_4· dppe)_3(NO_3)_4], Mr=1874.79, D_c=1.607 g·cm~(-3), Dm=1.62 g·cm~(-3), μ(MoKa)=11.69 cm~(-1), F(OOO)=942. The structure was solved by conventional heavy-atom techniques and refined by full-matrix least squares to give discrepany indices of R=0.048 and RW=0.060(W=1/[σ(Fo)~2+(PWT*Fo)~2+QWT]-Fo) for 5052 reflections. An empirical absorption correction program DIFABS was performed.Silver atoms are linked by bridging ligands of dppe and nitrate, forming a network extending in space. Each structural unit contains two binuclear subunits, of which silver atoms are bridged by nitrates. The two subunits are connected by one dppe ligand. Silver atoms are not equivalent in subunit and one of the nitrates functions not only as a monodentate bridging ligand, but also as an asymmetric bidentate chelating lingand. All coordinate configurations of silver are shown as distorted tetrahedron.  相似文献   

16.
沈扬林  金俊玲  段光雄  谢云鹏  卢兴 《化学学报》2020,78(11):1255-1259
原子精确的纳米硫银团簇由于其迷人的结构特征和潜在的应用价值而受到研究者的广泛关注.本工作通过溶液自组装的方法合成了两个新型核壳结构的硫银团簇[Ag56S12tBuS)20(CF3CO212]·6CH3CN·8H2O(Ag56)和[Ag58S12-(tBuS)20(CF3CO214(CH3CN)6]·6CH3CN(Ag58).单晶XRD结构表征表明两个硫银团簇的内部均包裹着Ag14单元:Ag56中Ag14内核单元为常见菱形十二面体结构,而Ag58中Ag14内核单元为罕见的纺锤形结构.Ag14内核单元的异构引起了两个硫银团簇外壳结构和形貌的变化,相比于Ag56中12个Ag6环形结构单元相互连接形成的球状外壳,Ag58的外层银原子按照“Ag4-Ag8-Ag10-Ag10-Ag8-Ag4”层状分布的方式形成了纺锤形外壳.紫外-可见吸收光谱和荧光光谱研究表明,硫银团簇Ag56Ag58结构的差异对其能级以及荧光性质都会产生影响.本工作中两个新型硫银团簇的成功分离丰富了硫银团簇的研究体系和结构类型,并为进一步探究硫银团簇的形成过程和性质提供了新的思路.  相似文献   

17.
一种新型偶氮杯[8]芳烃与Ag+的显色反应研究   总被引:2,自引:0,他引:2  
杯芳烃是继冠醚和环糊精之后的第三代主体分子,由于具有空腔可调节、构象可变换、并易于化学改性和修饰等特点,对其进行特定的结构修饰后,可作为离子和中性分子的分子识别。文献[10,11]报道5,17-(8-喹啉)偶氮基-25,26,27,28-四羟基杯[4]芳烃对Ni^2+有很高的选择性,  相似文献   

18.
采用Dmol3程序中密度泛函理论(DFT)的广义梯度方法GGA/BLYP和DND基组研究了银离子交换的丝光沸石([Ag]-AlMOR)结构及其对NOx分子吸附性能的影响, 获得吸附复合物的平衡几何结构参数、吸附能以及红外振动频率等数据. 结果表明, NOx分子与丝光沸石间的主要作用力为NOx分子中的氮(或氧)原子上的孤对电子和Ag+间的静电作用力. 吸附能数据表明, NOx分子以η1-N模式吸附在[Ag]-AlMOR分子筛中的结构更稳定; 在η1-N模式中, NOx分子吸附作用强度的次序为NO>NO2>N2O. 红外振动频率结果表明, 吸附态NOx分子中N—O和N—N键伸缩振动频率的位移趋势与N—O和N—N 键变化规律基本相一致. 另外, 对[Ag]-AlMOR分子筛的抗硫、抗水及抗氧化性能也进行了研究和分析.  相似文献   

19.
Electrochemical and photochemical properties of the tetrahedral cluster [Ru3Ir( 3-H)(CO)13] were studied in order to prove whether the previously established thermal conversion of this cluster into the hydrogenated derivative [Ru3Ir(-H)3(CO)12] also occurs by means of redox or photochemical activation. Two-electron reduction of [Ru3Ir( 3-H)(CO)13] results in the loss of CO and concomitant formation of the dianion [Ru3Ir( 3-H)(CO)12]2–. The latter reduction product is stable in CH2Cl2 at low temperatures but becomes partly protonated above 283K into the anion [Ru3Ir(-H)2(CO)12] by traces of water. The dianion [Ru3Ir( 3-H)(CO)12]2– is also the product of the electrochemical reduction of [Ru3Ir(-H)3(CO)12] accompanied by the loss of H2. Stepwise deprotonation of [Ru3Ir(-H)3(CO)12] with Et4NOH yields [Ru3Ir(-H)2(CO)12] and [Ru3Ir( 3-H)(CO)12]2–. Reverse protonation of the anionic clusters can be achieved, e.g., with trifluoromethylsulfonic acid. Thus, the electrochemical conversion of [Ru3Ir( 3-H)(CO)13] into [Ru3Ir(-H)3(CO)12] is feasible, demanding separate two-electron reduction and protonation steps. Irradiation into the visible absorption band of [Ru3Ir( 3-H)(CO)13] in hexane does not induce any significant photochemical conversion. Irradiation of this cluster in the presence of CO with irr>340nm, however, triggers its efficient photofragmentation into reactive unsaturated ruthenium and iridium carbonyl fragments. These fragments are either stabilised by dissolved CO or undergo reclusterification to give homonuclear clusters. Most importantly, in H2-saturated hexane, [Ru3Ir( 3-H)(CO)13] converts selectively into the [Ru3Ir(-H)3(CO)12] photoproduct. This conversion is particularly efficient at irr >340nm.  相似文献   

20.
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