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1.
Reactions of ethylenediamine solutions of K4Bi5 with Ni(PPh3)2(CO)2 yielded four novel hetero-atomic Bi/Ni deltahedral clusters. Three of them, the 7-atom pentagonal bipyramidal [Bi3Ni4(CO)6]3-, the 8-atom dodecahedral [Bi4Ni4(CO)6]2-, and the Ni-centered or empty 12-atom icosahedral [Nix@[Bi6Ni6(CO)8]4-, are closo-species according to both electron count and shape. The centered icosahedral cluster resembles packing in intermetallic compounds and belongs to the emerging class of intermetalloid clusters. The shape of the fourth cluster, [Bi3Ni6(CO)9]3-, can be derived from the icosahedral Ni-centered [Ni@[Bi6Ni6(CO)8]4- by removal of three Bi- and one Ni-atoms of two neighboring triangular faces. The clusters were structurally characterized by single-crystal X-ray diffraction in compounds with potassium cations sequestered by 2,2,2-crypt or 18-crown-6 ether. They were also characterized in solution by electrospray mass spectrometry.  相似文献   

2.
We report the synthesis, characterization, and computational rationalization of the first trimetallic deltahedral Zintl ions. The novel nine-atom clusters were structurally characterized as dimers of [(Sn(6)Ge(2)Bi)(2)](4-) with Ge-Ge intercluster bonds. They are synthesized either by reacting bimetallic clusters (Sn(9-x)Ge(x))(4-) with BiPh(3) or by direct extraction from precursors with nominal composition "K(4)Ge(4)Sn(4)Bi".  相似文献   

3.
The type of the reactions of addition of exo-bonded groups to deltahedral Zintl ions such as Ge9(n-) has been established as addition of anionic nucleophiles. Various nucleophiles such as Ph2Bi-, Ph2Sb-, Ph- interact with the relatively low-lying LUMO of Ge9(2-) and/or the half filled HOMO of Ge9(3-) and bond to the clusters. The title anions, characterized in their (K-crypt) salts where crypt = 4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo-[8.8.8]-hexacosane, and the previously characterized [Ph2Sb-Ge9-SbPh2](2-) are made by a reaction of K4Ge9 with SbPh3 in ethylenediamine. [Ph-Ge9-SbPh2](2-) is the first ogranically functionalized deltahedral Zintl ion, i.e., a deltahedral ion with a direct carbon-cluster covalent bond, that can exists without the substituents as well. The Ge(9) clusters resemble tricapped trigonal prisms with one elongated edge (one of the three edges parallel to the pseudo 3-fold axis). The two substituents are always bonded to the vertexes of such an elongated edge. The same is true for the intercluster bond in [Ph2Sb-Ge9-Ge9-SbPh2)](4-).  相似文献   

4.
We report the surfactant-directed assembly of mesoporous metal/germanium-based semiconducting materials from coupling of anionic (Ge 9) (4-) clusters with various linking metal ions. The resulting materials feature a metal/Ge 9 framework perforated by regular arrays of mesoporous channels. The permanent mesoporosity of the materials NU-MGe-2 (M = Sb, In, Sn, Pb, Cd), determined by N 2 physisorption measurements, corresponds to high internal BET surface areas from 127 to 277 m (2)/g and total pore volumes from 0.15 to 0.26 cm (3)/g. The mesoporous structures exhibit energy gaps in the range of 1.48-1.70 eV as well as strong photoluminescence at room temperature with emission energies varying from 740 to 845 nm. The emission depends on pore wall thickness and framework composition. The photoemission intensity in the mesoporous intermetallic germanium-based frameworks can be selectively suppressed by adsorbing electron-acceptor species such as tetracyanoethylene molecules but remains unchanged when exposed to electron-donor species such as tetrathiafulvalene molecules.  相似文献   

5.
K3Sb7 and Ni(COD)2 react in the presence of 2,2,2-cryptand in ethylenediamine solutions ( approximately 1:8 Ni/Sb molar ratio) to give dark-brown crystals of the paramagnetic cluster anion [Ni5Sb17]4- as the [K(2,2,2-crypt)]+ salt. The cluster has a Ni(cyclo-Ni4Sb4) ring unit that sits inside a Sb13 bowl. The structure is similar to that of the previously reported [Pd7As16]4- ion containing a Pd(cyclo-Pd4As4) ring unit that sits inside a Pd2As12 bowl. Density functional theory and bond valence analyses suggest delocalized charge distributions and intermetallic-like properties.  相似文献   

6.
Reactions of nine-atom deltahedral clusters (Zintl ions) of germanium, Ge9n- (n = 2, 3, 4), with alkyl chlorides, RCl (R = tBu, nBu, sBu, tAm), yielded the corresponding dialkylated dimers of Ge9 clusters [R-Ge9-Ge9-R]4-. The tBu derivative with [K(2,2,2-crypt)]+ countercations was characterized in the solid state by single-crystal X-ray diffraction as [K(2,2,2-crypt)]4[tBu-Ge9-Ge9-tBu].7en (monoclinic, C2/c, a = 35.0914(10) A, b = 24.8161(6) A, and c = 16.8782(5) A, beta = 94.0136(17) degrees , V = 14662.0(7) A3, and Z = 4) and in solution by 1H and 13C NMR. All species were also characterized in solution by electrospray mass spectrometry in the negative-ion mode. These are the first main group deltahedral clusters functionalized with purely organic substituents.  相似文献   

7.
8.
Six new derivatized deltahedral Zintl ions have been synthesized by reactions between the known Zintl ions Ge(9) (n-) with the halides R(3)EX and/or the corresponding anions R(3)E(-) for E=Ge or Sn. This rational approach is based on our previous discovery that these derivatization reactions are based on nucleophilic addition to the clusters. All species were structurally characterized as their salts with potassium countercations sequestered in 2,2,2-crypt or [18]crown-6 ether. The tin-containing anions were characterized also in solutions by (119)Sn NMR spectroscopy. The reaction types for such substitutions and the structures of the new anions are discussed.  相似文献   

9.
Deltahedral nine-atom clusters of silicon, Si(9)(2-), were synthesized by mild oxidation of a liquid ammonia solution of K(12)Si(17) with Ph(3)GeCl in the presence of 18-crown-6 (1,4,7,10,13,16-hexaoxacyclooctadecane) or 2,2,2-crypt (4,7,13,16,21,24-hexaoxa-1,10-diazabicyclo[8.8.8]hexacosane). The clusters were structurally characterized in [K(18-crown-6)](2)Si(9).C(5)H(5)N (yellow; orthorhombic, Pnma; a = 14.013(1), b = 18.108 (1), c = 18.320 (1) A; Z = 4) crystallized from a pyridine solution of the product of the aforementioned reaction in liquid ammonia. Si(9)(2-) is the first unequivocally characterized nine-atom cluster of group 14 with a charge of 2-. In addition to pyridine, the product from the reaction in liquid ammonia is also soluble in DMF, and the Si(9)(2-) clusters were characterized by mass spectrometry in such a solution. The more reduced clusters Si(9)(3-) have also been crystallized from pyridine solution. Cyclic voltammetry in both pyridine and DMF solutions clearly shows the Si(9)(2-)/Si(9)(3-) redox couple as one-electron reversible process. The structural similarities and differences between Si(9)(3-) and Si(9)(2-) are discussed herein.  相似文献   

10.
Elusive for over 100 years, deltahedral Zintl ions of silicon are finally synthesized and structurally characterized. The two clusters reported here, Si93- and Si52-, are analogous to known clusters of the heavier members of this group: Ge, Sn, and Pb.  相似文献   

11.
The reactions of appropriate ratios of K2TeO3 and [Mn2(CO)10)] in superheated methanol solutions lead to a series of novel cluster anions [Te4Mn3(CO)10] (1), [Te2Mn3(CO)9]2- (2), [Te2Mn3(CO)9]- (3), and [Te2Mn4(CO)12]2- (4). When cluster 1 is treated with [Mn2(CO)10]/KOH in methanol, paramagnetic cluster 2 is formed in moderate yield. Cluster 2 is oxidized by [Cu(MeCN)4]BF4 to give the closo-cluster [Te2Mn3(CO)9]- (3), while treatment of 2 with [Mn2(CO)10]/KOH affords the closo-cluster 4. IR spectroscopy showed that cluster 1 reacted with [Mn2(CO)10] to give cluster 4 via cluster 2. Clusters 1-4 were structurally characterized by spectroscopic methods or/and X-ray analyses. The core structure of 1 can be described as two [Mn(CO)3] groups doubly bridged by two Te2 fragments in a mu2-eta2 fashion. Both [Mn(CO)3] groups are further coordinated to one [Mn(CO)4] moiety. Cluster 2 is a 49 e- species with a square-pyramidal core geometry. While cluster 3 displays a trigonal-bipyramidal metal core, cluster 4 possesses an octahedral core geometry.  相似文献   

12.
13.
[PPh(4)][EI(4)] (E=As, Sb, Bi) salts were reacted with four and five equivalents of AgN(3) to form tetraazidopnictates and pentaazidopnictates of the type [PPh(4)][E(N(3))(4)] and [PPh(4)](2)[E(N(3))(5)], respectively. The synthesis of [PPh(4)][P(N(3))(4)] was also attempted from the reaction of P(N(3))(3) with [PPh(4)]N(3), but it yielded only the starting materials. Herein, we report the synthesis and structure elucidation of [PPh(4)][E(N(3))](4) (E=As, Sb) and pentaazidobismuthate, stabilized as the dimethyl sulfoxide (DMSO) anion adduct, [PPh(4)](2)[Bi(N(3))(5)(dmso)]. Successive anion formation along the series E(N(3))(3)+nN(3)(-) (n=1-3) and E(N(3))(5)+N(3)(-) was studied by density functional theory.  相似文献   

14.
For a long time, Zintl ions of Group 14 and 15 elements were considered to be remarkable species domiciled in solid-state chemistry that have unexpected stoichiometries and fascinating structures, but were of limited relevance. The revival of Zintl ions was heralded by the observation that these species, preformed in solid-state Zintl phases, can be extracted from the lattice of the solids and dissolved in appropriate solvents, and thus become available as reactants and building blocks in solution chemistry. The recent upsurge of research activity in this fast-growing field has now provided a rich plethora of new compounds, for example by substitution of these Zintl ions with organic groups and organometallic fragments, by oxidative coupling reactions leading to dimers, oligomers, or polymers, or by the inclusion of metal atoms under formation of endohedral cluster species and intermetalloid compounds; some of these species have good prospects in applications in materials science. This Review presents the enormous progress that has been made in Zintl ion chemistry with an emphasis on syntheses, properties, structures, and theoretical treatments.  相似文献   

15.
张建兴  黄德音 《有机化学》1996,16(2):157-159
异氰酸苯酯和N-[2-(4, 6-二甲基)-嘧啶基]-羟胺(5)反应生成1-[2-(4, 6-二甲基)-嘧啶基]-1-羟基-3-苯基脲(6)。化合物(6)在三乙胺存在下和氯甲酸乙酯反应生成2-[2-(4, 6-二甲基)-嘧啶基]-4-苯基-1, 2, 4-恶二唑烷-3, 5-二酮(1)。  相似文献   

16.
The reaction of the 3-substituted 4-aminopyrazolo[5, 1-c][1, 2, 4]triazines 1a-d with thiosemicarbazide hydrochloride in acetic acid gave new pyrazolo[5′,1′:3, 4][1, 2, 4]triazino[6, 5-f][1, 3, 4]thiadiazepines 3, 4 and 6 , which were converted into the 5-oxo derivatives 5 and 7 by hydrolysis in hydrochloric acid/acetic acid.  相似文献   

17.
Two K([2.2.2]crypt) salts of lanthanide-doped semimetal clusters were prepared, both of which contain at the same time two types of ternary intermetalloid anions, [Ln@Sn(7)Bi(7)](4-) and [Ln@Sn(4)Bi(9)](4-), in 0.70:0.30 (Ln = La) or 0.39:0.61 (Ln = Ce) ratios. The cluster shells represent nondeltahedral, fullerane-type arrangements of 14 or 13 main group metal atoms that embed the Ln(3+) cations. The assignment of formal +III oxidation states for the Ln sites was confirmed by means of magnetic measurements that reveal a diamagnetic La(III) compound and a paramagnetic Ce(III) analogue. Whereas the cluster anions with a 14-atomic main-group metal cage represent the second examples in addition to a related Eu(II) cluster published just recently, the 13-atomic cages exhibit a yet unprecedented enneahedral topology. In contrast to the larger cages, which accord to the Zintl-Klemm-Busmann electron number-structure correlation, the smaller clusters require a more profound interpretation of the bonding situation. Quantum chemical investigations served to shed light on these unusual complexes and showed significant narrowing of the HOMO-LUMO gap upon incorporation of Ce(3+) within the semimetal cages.  相似文献   

18.
电化学合成1, 4-双[2-(3, 4, 5-三甲氧基苯基)乙烯基]苯   总被引:5,自引:0,他引:5  
邱锡元 《有机化学》2000,20(3):348-351
1,4-双[2-(3,4,5-三甲氧基苯基]苯[简称HPV]采用有机电化学的方法合成,对合成的原理和方法进行研究和探讨,得到此化合物的三种异构体的淡黄色混合物,即含29.4%全顺式,44.7%顺-反式和25.9%全顺式。所得混合物熔点范围为103-155℃,总得率为92%。  相似文献   

19.
正如前文报道,l,3,4—噻二唑类杂环之所以有除草,植物生长调节,驱虫以及消炎等多种生物活性,无疑起因于噻唑母核。尽管母核上取代基不起主导作用,但它作为辅助基,在改善分子溶解性以及药效方面所产生的影响是不能忽略的。因而深入研究各种生物活性基团导入噻二唑环母核以制得多结构单元聚集于同一分子中的噻二唑新衍生物,对于开发多功能新药具有一定的理论意义和实际价值。  相似文献   

20.
Two novel 2D sheet-like complexes 1 and 2 have been prepared by reaction of p-sulfonatothiacalix[4]arene (TC4AS) with main-group metal ions (lead(II) or barium(II)) and 4,4'-bipyridine-N,N'-dioxide (4,4'-bpno). In both complexes 1 and 2, TC4AS molecules prefer 1,2-alternate conformation, forming 2D sheet-like layers in the presence of divalent ions and 4,4'-bpno ligand. The layers extend to 3D architectures via strong hydrogen bonding interactions. In addition, complexes 1 and 2 are thermally stable up to ca. 335 and 305 °C, respectively. It seems that the strong hydrogen bonds between the sheet-like layers impart the extraordinarily high degrees of stability to the structures. Further analysis indicates that complexes 1 and 2 are significantly different: (a) the divalent ions have different coordination environments due to the nature of the different ions; (b) TC4AS within complexes 1 and 2 connects to four Pb(II) or six Ba(II) ions, respectively; (c) 4,4'-bpno shows different connection modes; (d) in the solid state, complex 1 exhibits intense orange luminescence with triexponential decays, while complex 2 does not exhibit any obvious luminescence at cryogenic temperatures.  相似文献   

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