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1.
The chemoselectivities in the (π4s + π2s) cycloaddition reactions of tetraphenylcyclopentadienone (TPCD) with ethyl- and 1,1-dimethylallene have been determined and are compared with those observed for reaction with maleic anhydride.  相似文献   

2.
An oxidant promoted 1,3‐dipolar cycloaddition of benzimidazolium ylides to alkenes was developed for the preparation of 4H‐pyrrolo[1,2‐a]benzimidazole derivatives in moderate yields under mild conditions. In the presence of a suitable oxidant, the most commercially available “normal” alkenes, instead of alkynes or “abnormal” alkenes, could be used as dipolarophiles successfully. Moreover, CrO3/Et3N has been proved to be a more effective dehydrogenating reagent than MnO2 or tetrakispyridine cobalt (II) dichromate (TPCD) in this procedure.  相似文献   

3.
Two new complexes of imidazole alcohols, 4-hydroxymethylimidazole (4-CH2OHim) and 4-hydroxymethyl-5-methylimidazole (4-CH2OH-5-CH3im), with cobalt(II) of formula [CoL2(H2O)2](NO3)2 were obtained. These compounds were described through single X-ray diffraction studies, spectroscopic (Ir. Far-IR, UV-Vis-NIR) and magnetic measurements. In the present complexes imidazole ligands are bidentate coordinating the heterocyclic ring through pyridine-like nitrogen and the oxygen atom of the hydroxymethyl group (chromophore CoN2O4). The shape of Co(II) coordination polyhedra is that of a distorted octahedron, with the equatorial plane defined by the 4-CH2OHim (or 4-CH2OH-5-CH3im) bidentate ligands and two water molecules occupying axial positions (i.e. trans to each other). Formation of successive cobalt(II) complexes with 4-CH2OH-5-CH3im in aqueous solution was followed quantitatively by potentiometry.  相似文献   

4.
Cu4O12 Groups Built of Square Planar CuO4 Polygones in the Barium Vanadyl Oxocuprate(II) Phosphate Ba(VO)Cu4(PO4)4 Single crystals of Ba(VO)Cu4(PO4)4 have been prepared by solid state reactions just below the melting points of the reaction mixtures of BaP2O6, Cu3(PO4)2, CuO, V2O5 and V2O3 in evacuated closed quartz glas tubes. The compound crystallizes with tetragonal symmetry, Space group D? P4212, a = 9.560(2), c = 7.160(2) Å, Z = 2. Special and new features of the crystal structure are to each other isolated Cu4O12 and (VO)(PO4)4 groups. The crystal chemistry of the Cu4O12 groups is discussed with respect to other compounds containing out of plane connected square planar MO4 polygones.  相似文献   

5.
Synthesis and Crystal Structure of K2(HSO4)(H2PO4), K4(HSO4)3(H2PO4), and Na(HSO4)(H3PO4) Mixed hydrogen sulfate phosphates K2(HSO4)(H2PO4), K4(HSO4)3(H2PO4) and Na(HSO4)(H3PO4) were synthesized and characterized by X‐ray single crystal analysis. In case of K2(HSO4)(H2PO4) neutron powder diffraction was used additionally. For this compound an unknown supercell was found. According to X‐ray crystal structure analysis, the compounds have the following crystal data: K2(HSO4)(H2PO4) (T = 298 K), monoclinic, space group P 21/c, a = 11.150(4) Å, b = 7.371(2) Å, c = 9.436(3) Å, β = 92.29(3)°, V = 774.9(4) Å3, Z = 4, R1 = 0.039; K4(HSO4)3(H2PO4) (T = 298 K), triclinic, space group P 1, a = 7.217(8) Å, b = 7.521(9) Å, c = 7.574(8) Å, α = 71.52(1)°, β = 88.28(1)°, γ = 86.20(1)°, V = 389.1(8)Å3, Z = 1, R1 = 0.031; Na(HSO4)(H3PO4) (T = 298 K), monoclinic, space group P 21, a = 5.449(1) Å, b = 6.832(1) Å, c = 8.718(2) Å, β = 95.88(3)°, V = 322.8(1) Å3, Z = 2, R1 = 0,032. The metal atoms are coordinated by 8 or 9 oxygen atoms. The structure of K2(HSO4)(H2PO4) is characterized by hydrogen bonded chains of mixed HnS/PO4 tetrahedra. In the structure of K4(HSO4)3(H2PO4), there are dimers of HnS/PO4 tetrahedra, which are further connected to chains. Additional HSO4 tetrahedra are linked to these chains. In the structure of Na(HSO4)(H3PO4) the HSO4 tetrahedra and H3PO4 molecules form layers by hydrogen bonds.  相似文献   

6.
IR and Raman spectra of Te(OH)6.2NH4H2AsO4.(NH4)2HAsO4 (compound I) and Te(OH)6.2(NH4)2HAsO4 (compound II) are recorded and analysed. The symmetry of different groups and the vibrational interaction between them are discussed. The observed spectra suggest the existence of HAsO2−4 in II and coexistence of HAsO2−4 and H2AsO4 in I. The ammonium ion is found to execute hindered rotation in the lattice in both the compounds.  相似文献   

7.
Tin(II) methoxide reacts with N,N′‐dimethylaminoethanol (dmaeH) to yield Sn(dmae)2 ( 1 ) along with small amounts of the hydrolysis product Sn6(O)4(dmae)4 ( 2 ). The geometrically more regular iso‐structural cage Sn6(O)4(OEt)4 ( 3 ) was obtained as the only tractable product isolated from reaction of 2 and Sb(OEt)3, while 1 reacted with CdX2 (X = acac, I) to afford Sn(dmae)2Cd(acac)2 ( 4 ) and Sn(dmae)2CdI2 ( 5 ). The X‐ray structures of 2, 3 and 4 are reported. Decomposition of 4 under aerosol‐assisted chemical vapour deposition conditions leads to amorphous tin oxide films with no detectable cadmium (i.e. ca < 2% cadmium), rather than a stoichiometric Sn:Cd oxide. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

8.
Sulfates and Hydrogensulfates of Erbium: Er(HSO4)3-I, Er(HSO4)3-II, Er(SO4)(HSO4), and Er2(SO4)3 Rod shaped light pink crystals of Er(HSO4)3-I (orthorhombic, Pbca, a = 1195.0(1) pm, b = 949.30(7) pm, c = 1644.3(1) pm) grow from a solution of Er2(SO4)3 in conc. H2SO4 at 250 °C. From slightly diluted solutions (85%) which contain Na2SO4, brick shaped light pink crystals of Er(HSO4)3-II (monoclinic, P21/n, a = 520.00(5) pm, b = 1357.8(1) pm, c = 1233.4(1) pm, β = 92.13(1)°) were obtained at 250 °C and crystals of the same colour of Er(SO4)(HSO4) (monoclinic, P21/n, a = 545.62(6) pm, b = 1075.6(1) pm, c = 1053.1(1) pm, β = 104.58(1)°) at 60 °C. In both hydrogensulfates, Er3+ is surrounded by eight oxygen atoms. In Er(HSO4)3-I layers of HSO4 groups are connected only via hydrogen bridges, while Er(HSO4)3-II consists of a threedimensional polyhedra network. In the crystal structure of Er(SO4)(HSO4) Er3+ is sevenfold coordinated by oxygen atoms, which belong to four SO42–- and three HSO4-tetrahedra, respectively. The anhydrous sulfate, Er2(SO4)3, cannot be prepared from H2SO4 solutions but crystallizes from a NaCl-melt. The coordination number of Er3+ in Er2(SO4)3 (orthorhombic, Pbcn, a = 1270.9(1) pm, b = 913.01(7) pm, c = 921.67(7) pm) is six. The octahedral coordinationpolyhedra are connected via all vertices to the SO42–-tetrahedra.  相似文献   

9.
Bright orange (CuBr)3P4Se4 is obtained from the reaction of CuBr, P, and Se in stoichiometric amounts (CuBr : P : Se = 3 : 4 : 4). The composition and the crystal structure of the compound were determined from single crystal X‐ray diffraction data. Lattice constants are a = 33.627(2) Å, b = 6.402(1) Å, c = 19.059(1) Å, β = 90.19(3) °, V = 4103.2(3) Å3, and Z = 12. The compound crystallizes in a structure that is related to (CuI)3P4Se4. Cages of β‐P4Se4 are stacked along the b‐axis and are separated by columns of copper(I) bromide. However, the coordination of the β‐P4Se4 cage molecules to the copper atoms in the CuBr columns in (CuBr)3P4Se4 is quite different from (CuI)3P4Se4. The monoclinic compound (space group: P21, no. 4) has an almost orthorhombic metric in combination with a threefold superstructure in [100]. Structural aspects of (CuBr)3P4Se4 are discussed with respect to the heavier homologue (CuI)3P4Se4.  相似文献   

10.
Two one-dimensional complexes, [Ni(SCN)2(abba)2] n (abba?=?4-(4-aminobenzyl)benzenamine) (1) and [Ni(SCN)2(aptba)2] n (aptba?=?4-(4-aminophenylthio)benzenamine) (2), were synthesized and characterized by EA, IR, X-ray crystallography and thermal analysis. The single crystal X-ray structural analyses of 1 and 2 show the complexes to be 1D chain polymers as a result of dibenzenamine (dba) bridging. Each Ni is six-coordinate and adopts a slightly distorted octahedral geometry with four N atoms from four dba ligands and two N atoms from two NCS-groups. Adjacent Ni atoms and two dba ligands form a 24-membered macrocycle. Thermogravimetric analysis and differential thermogravimetric analysis of 2 show that the thermal decomposition of 2 includes four transitions.  相似文献   

11.
Synthesis of the Silatetraphospholanes (tBuP)4SiMe2, (tBuP)4SiCl2, and (tBuP)4Si(Cl)SiCl3 Molecular and Crystal Structure of (tBuP)4SiCl2 The reaction of the diphosphide K2[(tBuP)4] 7 with the halogenosilanes Me2SiCl2, SiCl4 or Si2Cl6 in a molar ratio of 1:1 leads via a [4 + 1]-cyclocondensation reaction to the silatetraphospholanes (tBuP)4SiMe2 1,1-dimethyl-1-sila-2,3,4,5-tetra-t-butyl-2,3,4,5-tetraphospholane, 1 , (tBuP)4SiCl2, 1,1-dichloro-1-sila-2,3,4,5-tetra-t-butyl-2,3,4,5-tetraphospholane, 2 , and (tBuP)4Si(Cl)SiCl3, 1-chloro-1-trichlorsilyl-1-sila-2,3,4,5-tetra-t-butyl-2,3,4,5-tetraphospholane, 3 , respectively, with the 5-membered P4Si ring system. The reaction leading to 1 is accompanied with the formation of the by-product Me2(Cl)-Si–(tBuP)4–Si(Cl)Me2 1a (5:1), which has a chain structure. On warming to 100°C 1a decomposes to 1 and Me2SiCl2. The compounds 2 and 3 do not react further with an excess of 7 due to strong steric shielding of the ring Si atoms by the t-butyl groups. 1, 2 and 3 could be obtained in a pure form and characterized NMR spectroscopically; 2 was also characterized by a single crystal structure analysis. 1a was identified by NMR spectroscopy only.  相似文献   

12.
Synthesis and Crystal Structures of (PPh4)2[In(S4)(S6)Cl] and (PPh4)2[In(S4)Cl3] InCl and PPh4Cl yield (PPh4)2[In2Cl6] in acetonitrile. This reacts with Na2S4 in presence of PPh4Cl, forming (PPh4)2[In(S4)(S6)Cl]. Its crystal structure was determined by X-ray diffraction (R = 0.075, 2 282 observed reflexions). It is isotypic with (PPh4)2[In(S4)(S6)Br] and contains anions with trigonal-bipyramidal coordination of In, Cl occupying an axial position, and the S4 and S6 groups being bonded in a chelate manner. The reaction of (PPh4)2[In2Cl6] and sulfur in acetonitrile yielded (PPh4)2[InCl5] and (PPh4)2[In(S4)Cl3]. The crystal structure analysis of the latter (R = 0.072, 4 080 reflexions) revealed an anion with distorted trigonal-bipyramidal coordination of In, the S4 group occupying one axial and one equatorial position; the S4 group shows positional disorder.  相似文献   

13.
New Hexafluoromanganates(III): (NH4)2NaMnF6, (NH4)2KMnF6, and (NH4)3MnF6 (NH4)2NaMnF6 and (NH4)2KMnF6 were prepared by solid state reaction in sealed platinum tubes under pressure. From solution pure (NH4)3MnF6 has been obtained at first time. The compounds crystallize in three different variants of the elpasolite structure: (NH4)2NaMnF6 tetragonally, (NH4)3KMnF6 monoclinic, (NH4)3MnF6 monoclinic, perhaps with triclinic symmetry. Relations between decreasing symmetry in structure and the JAHN -TELLER effect of Mn(III) as well as the influence of ionic radii are discussed. The reflectance spectra were measured, the magnetic properties of the title compounds as well as (NH4)2MnF5 were investigated.  相似文献   

14.
Synthesis and Crystal Structures of the Acetonitrile “Adducts” of Tetraphenylphosphonium Tetrachloroterbate(III) and -dysprosate(III), (Ph4P)TbCl4(CH3CN) and (Ph4P)DyCl4(CH3CN) Single crystals of (Ph4P)TbCl4(CH3CN) ( 1 ) and (Ph4P)DyCl4(CH3CN) ( 2 ) are obtained from the reaction of TbCl3 and DyCl3, respectively, with tetraphenylphosphonium chloride in acetonitrile. The crystal structures [monoclinic, P21/n (Nr. 14), Z = 4, a = 1065.5(4)/997.3(5) ( 1/2 ); b = 2160.4(5)/1835.8(7); c = 1232.7(3)/1626.7(5) pm, β = 98.82(3)/104.67(4)°; R1 = 0.0463/0.0469, wR2 = 0.1051/0.0971 for I > 2σ(I)] contain the dimeric anions [M22-Cl)21-Cl)6(CH3CN)2]2– (M = Tb, Dy) and (Ph4P)+ cations in slightly different packing modes.  相似文献   

15.
Synthesis and Structure of New Sodium Hydrogen Sulfates Na(H3O)(HSO4)2, Na2(HSO4)2(H2SO4), and Na(HSO4)(H2SO4)2 Three acidic sodium sulfates have been synthesized from the system sodium sulfate/sulfuric acid and have been crystallographically characterized. Na(H3O)(HSO4)2 ( A ) crystallizes in the space group P21/c with the unit cell parameters a = 6.974(2), b = 13.086(2), c = 8.080(3) Å, α = 105.90(4)°, V = 709.1 Å3, Z = 4. Na2(HSO4)2(H2SO4) ( B ) is orthorhombic (space group Pna21) with the unit cell parameters a = 9.970(2), b = 6.951(1), c = 13.949(3) Å, V = 966.7 Å3 and Z = 4. Na(HSO4)(H2SO4)2 ( C ) crystallizes in the triclinic space group P1 with the unit cell parameters a = 5.084(1), b = 8.746(1), c = 11.765(3) Å, α = 68.86(2)°, β = 88.44(2)°, γ = 88.97(2)°, V = 487.8 Å3 and Z = 2. All three compounds contain SO4 tetrahedra as HSO4? anions and additionally in B and C in form of H2SO4 molecules. The ratio H:SO4 determines the connectivity degree in the hydrogen bond system. In A , there are zigzag chains and dimers additionally connected via oxonium ions. Complex chains consisting of cyclic trimers (two HSO4? and one H2SO4) are present in B . In structure C , several parallel chains are connected to columns due to the greater content of H2SO4. Sodium cations show a distorted octahedral coordination by oxygen in all three structures, the NaO6 octahedra being “isolated” (connected via SO4 tetrahedra only) in A . Pairs of octahedra with common edge form Na2O10 dimeric units in C . Such double octahedra are connected via common corners forming zigzag chains in B .  相似文献   

16.
This study presents the first structural report of iranite, ideally CuPb10(CrO4)6(SiO4)2(OH)2 [copper decalead hexachromate bis(orthosilicate) dihydroxide], based on single‐crystal X‐ray diffraction data. Iranite is isomorphous with hemihedrite, with substitution of Cu for Zn and OH for F. The Cu atom is situated at the special position with site symmetry . The CrO4 and SiO4 tetrahedra and CuO4(OH)2 octahedra form layers that are parallel to (120) and are linked together by five symmetrically independent Pb2+ cations displaying a rather wide range of bond distances. The CuO4(OH)2 octahedra are corner‐linked to two CrO4 and two SiO4 groups, while two additional CrO4 groups are isolated. The mean Cr—O distances for the three nonequivalent CrO4 tetrahedra are all slightly shorter than the corresponding distances in hemihedrite, whereas the CuO4(OH)2 octahedron is more distorted than the ZnO4F2 octahedron in hemihedrite in terms of octahedral quadratic elongation.  相似文献   

17.
[{Cp(CO)3Mo}4In4(PSiMe3)4], an Organometallic In4P4-Heterocubane [{Cp(CO)3Mo}InCl2] reacts with P(SiMe3)3 in THF as solvent to form [{Cp(CO)3Mo}4In4(PSiMe3)4] 1. 1 crystallizes in the space group P1 . The lattice constants (at 208 K) are: a = 1 770.1(6), b = 1 490.3(6), c = 1 317.5(6) pm, α = 76.59(4),β = 88.54(3), γ = 88.98(3)°. According to the crystal structure analysis, 1 contains a slightly distorted In4P4-core with an alternating arrangement of In and P atoms. The In atoms are coordinated roughly tetrahedrally by three PSiMe3 groups (In–P: 256.9(3)–262.3(3) pm) and a {Cp(CO)3Mo} substituent (In? Mo: 278.0(2)–279.5(3) pm).  相似文献   

18.
Summary 2-Acetylpyridine N(4)-dihexyl- and N(4)-dicyclohexylthiosemicarbazone, HAc4DHex and HAc4DCHex, respectively, and FeIII, CoII, CoIII, NiII, CuII and ZnII complexes have been prepared and characterized by molar conductivities, magnetic susceptibilities and spectroscopic techniques. For many of the complexes, loss of the N(2)H hydrogen occurs, and the ligands coordinate to the metal centres as NNS monoanionic, tridentate ligands, e.g., [M(NNS)X] (M = CoII, NiII, CuII, NNS = Ac4DHex or Ac4DCHex and X = Cl or Br), [Fe(NNS)2]ClO4, [Co(NNS)2]BF4, [Cu(NNS)NO3] and [Zn(NNS)OAc]. ZnII ion is also chelated by neutral ligands in [Zn(HNNS)X2] (X = Cl, Br). In addition, [Ni(Ac4DHex)-(HAc4DHex)]X (X = BF4, ClO4) and [Ni(HAc4DCHex)2]-(BF4)2 are reported where the neutral thiosemicarbazone is coordinated via the pyridyl nitrogen, azomethine nitrogen and thione sulfur. Crystal structure determinations of HAc4DCHex and [Cu(Ac4DHex)Br] show the former to contain the bifurcated hydrogen bonded form and the latter to be planar with no significant interaction between neighbouring centres.  相似文献   

19.
Red single crystals of Gd2[Pt2(SO4)4(HSO4)2](HSO4)2 (triclinic, , Z = 1, a = 844.02(9), b = 908.50(9), c = 939.49(8) pm, α = 107.73(1)°, β = 112.10(1)°, γ = 103.53(1)°) were obtained by the reaction of [Gd(NO3)(H2O)7][PtCl6]·4H2O with sulfuric acid at 320 °C in a sealed glass ampoule. In the crystal structure, Pt2 dumbbells are coordinated by four chelating sulfate groups and two monodentate hydrogensulfate ions. Two further HSO4? ions are not bonded to the Pt2 dumbbell. The Gd3+ ions are eightfold coordinated by oxygen atoms. The IR data of Gd2[Pt2(SO4)4(HSO4)2](HSO4)2 are typical for these type of compounds. The thermal decomposition of the compound leads to elemental platinum and Gd2O3.  相似文献   

20.
Syntheses and Crystal Structures of [( t -Bu4Sb4)Fe(CO)4], [( t -Bu4Sb4)Mo(CO)5], and [( t -Bu3Sb4)Mo(η5-C5Me5)(CO)3] t-Bu4Sb4 reacts with Fe2(CO)9 to form [(t-Bu4Sb4)Fe(CO)4] ( 1 ). [(t-Bu4Sb4)Mo(CO)5] ( 2 ) is formed from (thf)Mo(CO)5 and t-Bu4Sb4. [(t-Bu3Sb4)Mo(η5-C5Me5)(CO)3] ( 3 ) is a product of the reaction of t-Bu4Sb4 with [(η5-C5Me5)Mo(CO)3]2. The crystal structures of 1–3 are reported.  相似文献   

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