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1.
The reaction of N,N′‐oligomethylenebis(3‐oxobutanamide)s with 1,1‐diarylethenes in the presence of manganese(III) acetate in acetic acid at 100° produced N N′‐oligomethylenebis(2‐methyl‐5,5‐diaryl‐4,5‐dihydrofuran‐3‐carboxamide)s. Similarly, the reaction of 3‐oxobutanamidoethyl 3‐oxobutanoate or N,N′‐(3,6‐dioxaoctamethylene)bis(3‐oxobutanamide) with 1,1‐diphenylethene gave (2‐methyl‐5,5‐diphenyl‐4,5‐dihydrofuran‐3‐amido)ethyl 2‐methyl‐5,5‐diphenyl‐4,5‐dihydrofuran‐3‐carboxylate or N,N′‐(3,6‐dioxa‐octamethylene)bis(2‐methyl‐5,5‐diphenyl‐4,5‐dihydrofuran‐3‐carboxamide) in moderate yields.  相似文献   

2.
[Ba(benzo‐15‐crown‐5)2](I3)2 and [Ba(benzo‐15‐crown‐5)2](I7)2 can be obtained in crystalline form by reacting benzo‐15‐crown‐5 (C14H20O5), barium iodide (BaI2), and iodine (I2) in ethan‐ole /dichloromethane. The triiodide consists of a sandwich‐like cation [Ba(benzo‐15‐crown‐5)2]2+ and an isolated symmetrically linear I3 anion. The unusual I7 anion in the heptaiodide can be described as a V‐shaped pentaiodide unit, which is connected with a slightly widened iodine molecule to the rare Z‐form of the heptaiodide ion. In the crystal structure, secondary bonding distances lead to almost planar ten‐membered iodine rings, which are connected by common edges to form staircase‐like bands.  相似文献   

3.
4.
A new 3D hemidirected mixed‐ligand lead(II) coordination polymer with the ligand 1,2‐di(4‐pyridyl)ethane bpa) and the two metal coordinated anions nitrate and thiocyanate, [Pb2(bpa)2(SCN)3(NO3)]n ( 1 ), has been synthesized and characterized by CHN elemental analysis, IR‐, 1H‐ and 13C NMR spectroscopy. The single crystal X‐ray data of compound 1 show that the complex is a three‐dimensional coordination polymer with two different Pb atoms with stereoactive electron lone pairs and six‐ and five‐coordinate hemidirected geometries, respectively.  相似文献   

5.
The platinum‐platinum attraction and the spectroscopic properties of [Pt3(μ‐CO)3(CO)3] (n = 3–5) were studied at the PBE level. Theoretical calculations are in agreement with experimental geometries. The absorption spectra of these platinum complexes were calculated by the single excitation time‐dependent (TD) density functional method. All complexes showed MLCT transitions interrelated with the intertriangular complexes. The values obtained at the PBE level are in agreement with the experimental color range. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009  相似文献   

6.
In [bis(3‐pyridylacrylato)cadmium(II)]n, the local coordination geometry around the cadmium center is based on an octahedron. The carboxylate acts as a tridentate ligand by bridging two cadmium atoms and binds a third cadmium atom via the pyridyl group with the result that a two‐dimensional layered network is formed. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

7.
The sample solution of KNO3 is ejected into the gas phase and the ionic dusters of K+(KNO3)n and NO3 (KNO3)m are formed and observed by electrospray ionization mass spectrometry (ESIMS). Hie full mass spectra of both the positive ion and the negative ion show that the differences between each peak nearby are all about 101 (m/z), which correspond to the molecular weight of KNO3. The general formula of the ionic clusters can be assigned as K+(KNO3)n and NO3′‐(KNO3)m..  相似文献   

8.
A well applicable preparative method for lithium perfluoroalkyltrimethoxyborates, Li[CnF2n+1B(OMe)3] (n = 3, 4, 6), was elaborated which is based on the reaction of B(OMe)3 with CnF2n+1Li generated from CnF2n+1H and t‐BuLi. Alternative perfluoroalkylation reactions of B(OMe)3 with perfluoropropyllithium generated from C3F7I and RLi, perfluoropropylmagnesium bromide, or perfluoropropyltrimethylsilane and potassium fluoride gave less satisfactory results for M[C3F7B(OMe)3]. The conversion of M[CnF2n+1B(OMe)3] salts (M = Li, BrMg) into K[CnF2n+1B(OMe)3] salts and basic properties of the new salts are reported.  相似文献   

9.
A novel 3D polymeric heteropolynuclear sodium(I) lead(II) complex containing different ligands, [NaPb(ClO4)(en)(NO2)2] was synthesized and characterized by elemental analysis and IR, and 1H‐, 13C‐, and 207Pb‐NMR spectroscopy. The single‐crystal X‐ray data of [NaPb(ClO4)(en)(NO2)2]n established that the complex is a three‐dimensional polymer, [(en)Pb(μ3‐ONO)2Na(μ3‐ONO)2Na(μ‐O2ClO2)Na]n. The Pb and Na atoms have four‐ and eight‐coordinate geometry, respectively. The lone pair of electrons at the PbII atom is ‘stereochemically active’.  相似文献   

10.
The interaction between {Au3(CH3N?COCH3)3} and {2,4,7‐trinitro‐9‐fluorenone} and the electronic structure and spectroscopic properties of {Au3(CH3N = COCH3)3}n·{2,4,7‐trinitro‐9‐fluorenone} (n = 1,2) are studied at the HF, MP2, and PBE levels. Secondary π‐interactions (Au‐fluorenone) were found to be the main contribution to short‐range stability in the {Au3(CH3N?COCH3)3}n·{2,4,7‐trinitro‐9‐fluorenone} complex. At the MP2 and PBE levels, Au‐C equilibrium distances of 292.3 and 304.0 pm and interaction energies of 105.3 and 24.9 kJ/mol were found, respectively. The absorption spectra of these complexes were calculated by the single excitation time‐dependent method at the PBE level. The theoretical values obtained are in agreement with the experimental range. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010  相似文献   

11.
Two new ZnII(μ‐4,4′‐bipy) coordination polymers with acetate anions, [Zn(4,4′‐bipy)(AcO)2] ( 1 ) and [Zn2(4,4′‐bipy)(AcO)4] ( 2 ), have been synthesized. The compounds were characterized with elemental analysis, IR‐, 1H NMR‐, 13C NMR spectroscopy and studied by thermal analysis, fluorescence measurements and x‐ray crystallography. The structural studies of compound 1 suggest the structure is a coordination polymer of zinc(II) consisting of linear double chains formed by bridging 4,4′‐bipy ligand and connection of the acetate‐bridged centrosymmetric [Zn2(OAc)2]2+ nodes.  相似文献   

12.
Red crystals of [NMeEt3]2n[TeBr6(Se2Br2)3]n ( 1 ) were isolated when selenium and bromine (1:1) were allowed to react in acetonitrile solution in the presence of tellurium(IV) bromide and methyltriethylammonium bromide (1:2). The salt 1 crystallizes in the monoclinic space group C2/c with the cell dimensions a = 27.676(6) Å, b = 9.665(2) Å, c = 18.796(4) Å and ß = 124.96(3)° (120 K). The [TeBr6(Se2Br2)3]2— anions contain nearly regular octahedral [TeBr6]2— ions which are incorporated into a polymeric chain by bonding contacts between 3 facial bromo ligands and 3 Se2Br2 molecules, one of which is situated on the twofold symmetry axis. The distances between the μBr ligands and the SeI atoms of the Se2Br2 molecules are observed in the range 3.308(2) — 3.408(2) Å and can tentatively be interpreted as donor‐acceptor bonds with μBr as donors and Se2Br2 as acceptors. The TeIV—Br distances are in the range 2.669(1) — 2.687(1) Å. The bond lengths in the connecting Se2Br2 molecules are: SeI—SeI = 2.267(2) and 2.281(2) Å, SeI—Br = 2.340(1), 2.353(1) and 2.337(1) Å.  相似文献   

13.
The hydrothermal reaction of Cd(NO3) · 4H2O with 4,4′‐bipyridine (bipy) and 3‐carboxyphenoxyacetatic acid (3‐H2CPOA) afforded a 3D metal‐organic framework (MOF) [Cd(3‐CPOA)(bipy)]n · 3.5nH2O, which was characterized by elemental analyses, IR spectroscopy, thermogravimetric analyses, and X‐ray diffraction. The single‐crystal structural analysis revealed that it has a Cds‐type topological network with 1D channels that contain encapsulated water molecular tapes.  相似文献   

14.
《Chemphyschem》2003,4(4):343-348
Lithium ionic conductivity and phase transitions in a series of lithium halides hydrates and hydroxides with general formula Li3‐n(OHn)X (0.83≤n≤2; X=Cl,Br) were studied using impedance measurements and 1H and 7Li NMR spectroscopy. All compounds studied in this work crystallize in the antiperovskite structure or are closely related to this structure type. With the exception of LiCl?H2O, all compounds with integer lithium content exhibit good lithium ionic conductivity in their high temperature cubic phases above T=33 °C. Lithium doping of samples LiX?H2O and Li2(OH)X leads to a suppression of the phase transition into the noncubic phases and the good ionic conductivity is extended down to lower temperatures (T<0 °C). Thus, lithium doping of the lithium halide hydrates provides a promising tool for tailoring the ionic conductivity at ambient temperatures to its optimum value.  相似文献   

15.
The title two‐dimensional hydrogen‐bonded coordination compounds, [Cu(C8H5O4)2(C4H6N2)2], (I), and [Cu(C8H7O2)2(C4H6N2)2]·H2O, (II), have been synthesized and structurally characterized. The molecule of complex (I) lies across an inversion centre, and the Cu2+ ion is coordinated by two N atoms from two 4‐methyl‐1H‐imidazole (4‐MeIM) molecules and two O atoms from two 3‐carboxybenzoate (HBDC) anions in a square‐planar geometry. Adjacent molecules are linked through intermolecular N—H...O and O—H...O hydrogen bonds into a two‐dimensional sheet with (4,4) topology. In the asymmetric part of the unit cell of (II) there are two symmetry‐independent molecules, in which each Cu2+ ion is also coordinated by two N atoms from two 4‐MeIM molecules and two O atoms from two 3‐methylbenzoate (3‐MeBC) anions in a square‐planar coordination. Two neutral complex molecules are held together via N—H...O(carboxylate) hydrogen bonds to generate a dimeric pair, which is further linked via discrete water molecules into a two‐dimensional network with the Schläfli symbol (43)2(46,66,83). In both compounds, as well as the strong intermolecular hydrogen bonds, π–π interactions also stabilize the crystal stacking.  相似文献   

16.
We report on ab initio calculations at the G2(MP2) level of the structures and Al-N(P) bond complexation energies of the (CH(3))(n)H(3)(-)(n)AlNX(3) and (CH(3))(n)H(3)(-)(n)()AlPX(3) (X = H, F, and Cl; n = 0-3) donor-acceptor complexes. For the (CH(3))(3)AlNX(3) and (CH(3))(3)AlPX(3) complexes, the C(3)(v) symmetry is found to be favored, and for the other complexes the C(s) symmetry is found to be favored. The G2(MP2) calculated complexation energies show for the amine ligands the trend NH(3) > NCl(3) > NF(3). A similar trend PH(3) approximately PCl(3) > PF(3) is predicted for the phosphane ligands. The NBO partitioning scheme shows that there is no correlation between the stability and the charge transfer.  相似文献   

17.
The molecular structures of the three title nitro‐substituted phenyl­aceto­nitriles, C8H6N2O2, at 123 K show that the mol­ecules are linked together very differently. In the 2‐ and 4‐nitro compounds, there are both O?H and Ncyano?H interactions, whereas the crystal lattice of the 3‐nitro compound is essentially built up by O?H interactions. The O atoms seem to prefer the aromatic H atoms, while the cyano N atoms prefer the methyl­ene H atoms. The phenyl–nitro torsion angles are ?19.83 (13), ?5.69 (12) and ?2.88 (12)°, while the phenyl–cyano­methyl torsion angles are ?62.27 (12), ?147.99 (9) and ?16.75 (14)° in the 2‐, 3‐ and 4‐NO2‐substituted compounds, respectively.  相似文献   

18.
The title compound, [Cu(C7H5O3)2(C6H6N2O)2(H2O)2], is a two‐dimensional hydrogen‐bonded supramolecular complex. The CuII ion resides on a centre of symmetry and is in an octahedral coordination environment comprising two pyridine N atoms, two carboxylate O atoms and two O atoms from water molecules. Intermolecular N—H...O and O—H...O hydrogen bonds produce R22(4), R22(8) and R22(15) rings which lead to one‐dimensional polymeric chains. An extensive two‐dimensional network of N—H...O and O—H...O hydrogen bonds and C—H...π interactions are responsible for crystal stabilization.  相似文献   

19.
In the isomeric title compounds, viz. 2‐, 3‐ and 4‐(chloro­methyl)pyridinium chloride, C6H7ClN+·Cl?, the secondary interactions have been established as follows. Classical N—H?Cl? hydrogen bonds are observed in the 2‐ and 3‐isomers, whereas the 4‐isomer forms inversion‐symmetric N—H(?Cl??)2H—N dimers involving three‐centre hydrogen bonds. Short Cl?Cl contacts are formed in both the 2‐isomer (C—Cl?Cl?, approximately linear at the central Cl) and the 4‐isomer (C—Cl?Cl—C, angles at Cl of ca 75°). Additionally, each compound displays contacts of the form C—H?Cl, mainly to the Cl? anion. The net effect is to create either a layer structure (3‐isomer) or a three‐dimensional packing with easily identifiable layer substructures (2‐ and 4‐isomers).  相似文献   

20.
Compounds including the free or coordinated gas‐phase cations [Ag(η2‐C2H4)n]+ (n=1–3) were stabilized with very weakly coordinating anions [A]? (A=Al{OC(CH3)(CF3)2}4, n=1 ( 1 ); Al{OC(H)(CF3)2}4, n=2 ( 3 ); Al{OC(CF3)3}4, n=3 ( 5 ); {(F3C)3CO}3Al‐F‐Al{OC(CF3)3}3, n=3 ( 6 )). They were prepared by reaction of the respective silver(I) salts with stoichiometric amounts of ethene in CH2Cl2 solution. As a reference we also prepared the isobutene complex [(Me2C?CH2)Ag(Al{OC(CH3)(CF3)2}4)] ( 2 ). The compounds were characterized by multinuclear solution‐NMR, solid‐state MAS‐NMR, IR and Raman spectroscopy as well as by their single crystal X‐ray structures. MAS‐NMR spectroscopy shows that the [Ag(η2‐C2H4)3]+ cation in its [Al{OC(CF3)3}4]? salt exhibits time‐averaged D3h‐symmetry and freely rotates around its principal z‐axis in the solid state. All routine X‐ray structures (2θmax.<55°) converged within the 3σ limit at C?C double bond lengths that were shorter or similar to that of free ethene. In contrast, the respective Raman active C?C stretching modes indicated red‐shifts of 38 to 45 cm?1, suggesting a slight C?C bond elongation. This mismatch is owed to residual librational motion at 100 K, the temperature of the data collection, as well as the lack of high angular data owing to the anisotropic electron distribution in the ethene molecule. Therefore, a method for the extraction of the C?C distance in [M(C2H4)] complexes from experimental Raman data was developed and meaningful C?C distances were obtained. These spectroscopic C?C distances compare well to newly collected X‐ray data obtained at high resolution (2θmax.=100°) and low temperature (100 K). To complement the experimental data as well as to obtain further insight into bond formation, the complexes with up to three ligands were studied theoretically. The calculations were performed with DFT (BP86/TZVPP, PBE0/TZVPP), MP2/TZVPP and partly CCSD(T)/AUG‐cc‐pVTZ methods. In most cases several isomers were considered. Additionally, [M(C2H4)3] (M=Cu+, Ag+, Au+, Ni0, Pd0, Pt0, Na+) were investigated with AIM theory to substantiate the preference for a planar conformation and to estimate the importance of σ donation and π back donation. Comparing the group 10 and 11 analogues, we find that the lack of π back bonding in the group 11 cations is almost compensated by increased σ donation.  相似文献   

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