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1.
Dialkylpropargyl(3-,-cyclohexenylpropargyl)amrnonium salts are cyclized in the presence of a base catalyst to give dialkyltetrahydrobenzlfliso-indoline salts in high yields. When the 3--cyclohexenylpropargyl and 3 phenylpropargyl groups are both present in the ammonium salt molecule, cyclization proceeds in more than one direction. Salts which contain both the 3-a-naphthylpropargyl and 3-alkenylpropargyl groups are also cyclized in two possible ways.Institute of Organic Chemistry, Republican Academy of Sciences, Armenia, Yerevan. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 328–332, March, 1996. Original article submitted September 30, 1995.  相似文献   

2.
《Polyhedron》2003,22(14-17):1777-1782
(PPh4)2[Mn12O12(O2CCHCl2)16(H2O)4] (3) has been prepared by the two-electron reduction of [Mn12O12(O2CCHCl2)16(H2O)4] (2) using iodide. Crystallization from CH2Cl2/hexanes yields a mixture of two crystal forms, 3·4CH2Cl2·H2O (3a) and 36CH2Cl2 (3b), which are triclinic and monoclinic, respectively. They are both trapped valence 2Mn(II), 6Mn(III), 4Mn(IV). DC magnetization data for dried, unsolvated 3 in 1.80–4.00 K and 10–70 kG ranges were fit to give S=10, D=−0.28 cm−1, g=2.00. Frequency-dependent out-of-phase (χM) signals in AC susceptibility studies on crystalline sample of 3a and 3b combined with DC relaxation decay data were fit to the Arrhenius equation to give an effective energy barrier of Ueff=18.5 and 30.3 K, respectively. Magnetization vs. DC field sweeps on single crystals of 3a and 3b gave hysteresis loops containing steps due to quantum tunneling of magnetization (QTM). The step separations yielded ∣D∣/g values of 0.087 and 0.14 cm−1, and consequently U=20 and 39 K (for g=2) for 3a and 3b, respectively, suggesting that the differences in Ueff are primarily caused by changes to D. This work demonstrates the sensitivity of the magnetic properties of [Mn12]2− single-molecule magnets to subtle differences in their environment.  相似文献   

3.
Strain measurement and quasiequilibrium thermogravimetry were used to study the dissociation processes of two clathrates, [Ni(MePy)4(NCS)2]·(MePy) and [Cu(MePy)4(NCS)2]·2/3(MePy), accompanied by the liberation of MePy into the gaseous phase. In the Ni clathrate dissociation process in the temperature range 298–368 K the liberated MePy was redistributed between the solid clathrate and gaseous phases; the MePy vapour pressure over the clathrate is a function of temperature and the guest contenty, which agrees with the presence in the MePy-[Ni(MePy)4(NCS)2] system of a wide range of -clathrate solutions, [Ni(MePy)4(NCS)2y(MePy). The same methods used to study the Cu clathrate dissociation resulted in conclusions different from those obtained for the dissociation process of the above clathrate: the process is described by the equation [Cu(MePy)4(NCS)2]·2/3(MePy)solid =[Cu(MePy)2(NCS)2]solid+22/3(MePy)gas; the temperature dependence of the Mepy vapour pressure over the solid sample does not depend on its composition, which points to the absence from the system of solid solutions based on the clathrate. Standard changes of the enthalpy, entropy, and isobaric-isothermal reaction potential for the temperature range 292–325 K are equal to 178.6±1.7 kJ (mole of clathrate)–1, 463±5.6 J (mole of clathrate)–1 K–1, and 40.4±2.4 kJ (mole of clathrate)–1, respectively.  相似文献   

4.
硫氰酸根的结构为N三C-S-,其两端的N原子和S原子分别有一对和三对孤对电子,因此,硫氰酸根可采用多种不同的配位模式与金属离子发生配位.硫氰酸根可作为单齿配体与一个金属离子配位,形成M-SCN或M-NCS的单核配合物,也可以作为桥联配体同时与两个、三个甚至四个金属离子配位形成多核配合物[1-3];另一方面,硫氰酸根是一个具有一定共轭性的偶极子,可传递磁相作用.因此,选择硫氰酸根作为桥联配体,将多个顺磁金属离子桥联形成一维、二维或三维结构的多核金属配合物分子,并研究它们的磁性已成为分子磁学的一个研究领域[4-6].本文仅报道标题配合物的合成与晶体结构.  相似文献   

5.
Two new salts, [2-NaMePy]2[Ni(i-mnt)2] (1) and [2-NaMe-4-MePy]2[Ni(i-mnt)2] (2) ([2-NaMePy]+ = 1-(2′-naphthylmethyl)pyridinium, [2-NaMe-4-MePy]+ = 1-(2′-naphthylmethyl)-4-methylpyridinium and i-mnt2? = iso-maleonitriledithiolate), have been prepared and characterized by elemental analyses, UV, IR, molar conductivity, and single crystal X-ray diffraction. The anions in 1 form a 1-D chain through short C ··· N interactions between the anions, while the cations in 2 stack a 1-D column via C–H ··· π and π ··· π stacking interactions between the cations. The effect of weak intramolecular interactions such as C–H ··· N, C–H ··· S, C–H ··· Ni hydrogen bonds, and π ··· π stacking interactions between the cations and the anions further generate a 3-D network structure. The change of the molecular topology of the countercation when the 4-substituted group in the pyridine ring is changed from H atom to CH3 group results in different crystal system, space group, and the stacking mode of the cations and anions of 1 and 2.  相似文献   

6.
CRYSTAL AND MOLECULAR STRUCTURE OF [K(C_(14)H_(20)O_5)_2]_2[Co(NCS)_4]   总被引:1,自引:0,他引:1  
<正> The title complex (Mr= 1442.6) crystallizes in the monoclinic, space group PC, with a =14.515(7),b =15.773(5), c =16.287(11)51,β=95.13(5)°,Z=2,V=3713.8A3,Dc=1.29 g·cm-3. The structure was solved by Patterson method and the final R=0.068. The potassium atom in the cation lies between the two planes of the oxygen atoms from two benzo-15-crown-5 molecules.  相似文献   

7.
《中国化学快报》2023,34(1):107207
To investigate the reactivity of homoatomic clusters [E9]4? (E = Si-Pb) and intermetalloid clusters [M@E9]q?, the reactions of the Zintl anions [Sn9]4? and [Ni@Sn9]4? with the CdMes2 (Mes = Mesitylene) in the presence of 2.2.2-crypt were carried out. Two new compounds [K(2.2.2-crypt)]6[(Sn9)Cd(Sn9)]·en (1) and [K(2.2.2-crypt)]6[(Ni@Sn9)Cd(Ni@Sn9)]·en (2) were afforded. Both 1 and 2 were characterized by single-crystal X-ray diffraction, energy dispersive X-ray (EDX), and electrospray ionization mass spectrometry (ESI-MS), and can be viewed as two [Sn9]4? or [Ni@Sn9]4? subunits bridged by Cd ion in an η3:η3 coordination mode. Quantum chemical calculations reveal the relationships between the geometries and electronic structures of clusters 2a, [Ni3Ge18]4? and [Cu4@Sn18]4?. Further electron localization technique (AdNDP method) was performed to explain chemical bonding patterns of 1a.  相似文献   

8.
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   

9.
The addition of PPh2H, PPhMeH, PPhH2, P(para-Tol)H2, PMesH2 and PH3 to the two-coordinate Ni0 N-heterocyclic carbene species [Ni(NHC)2] (NHC=IiPr2, IMe4, IEt2Me2) affords a series of mononuclear, terminal phosphido nickel complexes. Structural characterisation of nine of these compounds shows that they have unusual trans [H−Ni−PR2] or novel trans [R2P−Ni−PR2] geometries. The bis-phosphido complexes are more accessible when smaller NHCs (IMe4>IEt2Me2>IiPr2) and phosphines are employed. P−P activation of the diphosphines R2P−PR2 (R2=Ph2, PhMe) provides an alternative route to some of the [Ni(NHC)2(PR2)2] complexes. DFT calculations capture these trends with P−H bond activation proceeding from unconventional phosphine adducts in which the H substituent bridges the Ni−P bond. P−P bond activation from [Ni(NHC)2(Ph2P−PPh2)] adducts proceeds with computed barriers below 10 kcal mol−1. The ability of the [Ni(NHC)2] moiety to afford isolable terminal phosphido products reflects the stability of the Ni−NHC bond that prevents ligand dissociation and onward reaction.  相似文献   

10.
The cluster [Mo3S4(HNTA)3]2? reacts in acidic solution with LaCl3 to form a new hybrid layered compound La0.75Cl0.25[Mo3S4(HNTA)3]·18H2O (1) as crystals. Compound 1 has been structurally characterized by XRD, FTIR, TGA and elemental analysis. 1 crystallizes in the chiral P6(3) space group with a = 19.319(4) Å, c = 31.094(14) Å, V = 10,050(5) Å3 and Z = 8. The asymmetric unit contains four independent [Mo3S4(HNTA)3]2? anions. Three of them are directly connected to the La3+ cations through the carbonyl groups belonging to the coordinated carboxylates to give a 2D arrangement. The stacking of the 2D arrangements gives rise to the 3D network through hydrogen bonds between water molecules and the remaining hanging protonated carboxylate ligands. The resulting hexagonal network draws large channels (about 12 Å in diameter), filled by the fourth [Mo3S4(HNTA)3]2? unit, which appears uncoordinated and then could be viewed as a guest component.  相似文献   

11.
The [NpO2(DPPMO2)2Cl][NpO2Cl4] complex (where DPPMO2 = bis(diphenylphosphino)methanedioxide) contains the linear neptunyl group, {NpO2}2+, with two bidentate P=O donor ligands. Coordinating anion Cl? fills the fifth equatorial coordination site yielding a complex of general formula [NpO2(DPPMO2)2X]2[Y] (1) (where X = Cl? and Y = [NpO2Cl4]2?. Reaction between our newly prepared neptunium starting material [NpO2Cl2(thf)]n and phosphinimine ligand produced crystals of [Ph3PNH2]2[NpO2Cl4] (2). Compounds 1 and 2 have been structurally characterised.  相似文献   

12.
The crystal structure of the title compound has been determined from single crystal diffractometer data. The crystals are monoclinic, space group P21/c, a = 12.112(3), b = 7.217(2), c = 16.359(4), β = 111.96(10), Z = 4.1845 reflections were refined to a final R = 4.7%. The crystals contain water, NH4+ and [UO2(C3H2O4)2]n2n−1 ions. In the latter, one malonate group is bidentate and the second terdentate, giving chains parallel to b. Both ligands form six-membered rings with uranium. The uranyl UO distance (mean value) is 1.76 Å and the geometry around the uranium is approximately pentagonal bipyramidal.  相似文献   

13.
The reaction of pentaphenylantimony with mercury iodide affords the ionic complex [Ph4Sb] 2 + [Hg2I6]2?·Ph2Hg (I). The [Ph4Sb] 2 + [Hg2I6]2? (II) and [Ph4Sb] 2 + [Cd2I6]2? (III) complexes are synthesized from tetraphenylantimony iodide and mercury and cadmium iodides. The [Ph4Sb] 2 + [Hg4I10]2? complex (IV) is prepared from tetraphenylantimony 2,4-dimethylbenzenesulfonate and mercury iodide. According to the X-ray diffraction data, the Sb atom in the [Ph4Sb]+ cations of complex I has virtually ideal tetrahedral coordination (the CSbC angles are 108.09°–109.64°). In the central square fragment Hg2I2 of the [Hg2I6]2? anion, the Hg-Ibr bond lengths are 2.825 and 3.075 Å, and the terminal iodine atoms are more strongly bonded to the mercury atoms (Hg-Iterm 2.691 and 2.700 Å). The [Cd2I6]2? anion in complex III has a similar structure (the Cd-Ibridg and Cd-Iterm distances are 2.865, 2.872 and 2.723, 2.748 Å, respectively). The anions in complex IV are joined by I…Hg (3.651 Å) and I…I (4.058 Å) interactions into an infinite dimeric network.  相似文献   

14.
The structures of the mixed-ligand complexes Zn(4,4-Bipy){(n-C3H7)2NCS2}2 (I) and Zn2(4,4-Bipy){(n-C3H7)2NCS2}4 (II) were determined by single crystal X-ray diffractometry (CAD-4 diffractometer, MoK radiation, 2479 and 1616 Fhkl, R = 0.0550 and 0.0523). The crystals are monoclinic with cell parameters a = 16.560(2), b = 11.423(1), c = 15.319(2) , = 94.27(1)°, V = 2889.8(6) 3, Z = 4, space group P21/c (for I) and a = 8.515(1), b = 10.965(1), c = 27.816(3) , = 95.860(1)°, V = 2583.5(5) 3, Z = 2, space group P21/n (for II). The structure of I is composed of discrete mononuclear molecules; the structure of II consists of discrete centrosymmetric binuclear molecules. The coordination polyhedra of the Zn atoms (c.n. 5) are formed by four S atoms of the two cyclic bidentate dithiocarbamate ligands and the N atom of the 4,4-Bipy ligand, which is monodentate in I and bridging bidentate in II. Molecular packings and interactions in the structures are considered.  相似文献   

15.
In this work, the largest heterometallic supertetrahedral clusters, [Zn6Ge16]4− and [Cd6Ge16]4−, were directly self-assembled through highly-charged [Ge4]4− units and transition metal cations, in which 3-center–2-electron σ bonding in Ge2Zn or Ge2Cd triangles plays a vital role in the stabilization of the whole structure. The cluster structures have an open framework with a large central cavity of diameter 4.6 Å for Zn and 5.0 Å for Cd, respectively. Time-dependent HRESI-MS spectra show that the larger clusters grow from smaller components with a single [Ge4]4− and ZnMes2 units. Calculations performed at the DFT level indicate a very large HOMO–LUMO energy gap in [M6Ge16]4− (2.22 eV), suggesting high kinetic stability that may offer opportunities in materials science. These observations offer a new strategy for the assembly of heterometallic clusters with high symmetry.  相似文献   

16.
[FeII(SPh)4]2− (1) and [FeII(SePh)4]2− (2) exhibit high catalytic activity in the oxidation of benzoin with p-benzoquinone or air and of p-substituted benzhydrol with air under mild conditions (1 atm, 25 °C). p-Substitution of benzhydrols shows a trend in the oxidation rate: 4-Cl>H>4-OMe. Furthermore, the observed isotope effect of kH/kD = 4.0 (catalyzed by [Fe(Sph)4]2− (1)) and 3.3 (catalyzed by [Fe(SePh)4]2− (2)) in the p-benzoquinone oxidation of benzoin indicates that the methine hydrogen of benzoin and benzhydrol is released as a proton in the rate-determining step.  相似文献   

17.
硫氰酸根的结构为N≡C-S-,其两端的N原子和S原子分别有一对和三对孤对电子,因此,硫氰酸根可采用多种不同的配位模式与金属离子发生配位。硫氰酸根可作为单齿配体与一个金属离子配位,形成M-SCN或M-NCS的单核配合物,也可以作为桥联配体同时与两个、三个甚至四个金属离子配位形成多核配合物犤1~3犦;另一方面,硫氰酸根是一个具有一定共轭性的偶极子,可传递磁相作用。因此,选择硫氰酸根作为桥联配体,将多个顺磁金属离子桥联形成一维、二维或三维结构的多核金属配合物分子,并研究它们的磁性已成为分子磁学的一个研究领域…  相似文献   

18.
由于在电学、磁学、光学、吸附、离子交换和催化等领域具有潜在的应用价值,具有开放骨架结构的金属磷酸盐的合成一直受到人们的广泛关注。在这些磷酸盐微孔化合物中,磷酸锌晶体是拓扑结构最为丰富的一种犤1犦。自从Stucky等犤2犦报道具有SOD、Li-ABW、FAU等已知结构磷酸锌的合成以来,已经有近百种具有0-D犤3,4犦,1-D犤5,6犦,2-D犤7~9犦,3-D犤10~13犦结构的磷酸锌被成功地合成出来。其中令人瞩目的是具有螺旋孔道的手性磷酸锌犤14犦以及具有二十四元环孔道的两种微孔磷酸锌化合物犤15,16犦的合成。这些化合物大多是采用水热技术以有…  相似文献   

19.
Russian Journal of Organic Chemistry -  相似文献   

20.
The dependence of the rate constants for the oxidation of [Co(en)2amS]2+ (amS=–SCH2CH2NH2 2– by IO4– on solvent composition has been established for aqueous mixtures of MeOH, i-PrOH, t-BuOH, urea (U), ethylene carbonate (EC), acetonitrile (AN), dimethyl formamide (DMF) and acetone (Me2CO). Addition of aprotic cosolvents leads to marked decrease in the reaction rate in comparison to monohydroxylic alcohols. Alcohols inhibit the reaction rate in order MeOH < i-PrOH < t-BuOH. The change in solvation on going from the initial to the transition state are discussed in terms of the Gibbs transfer function, Gt0.  相似文献   

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