首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
The diphosphazane ligands of the type, (C20H12O2)PN(R)P(E)Y2 (R = CHMe2 or (S)-*CHMePh; E = lone pair or S; Y2 = O2C20H12 or Y = OC6H5 or OC6H4Me-4 or OC6H4OMe-4 or OC6H4But-4 or C6H5) bearing axially chiral 1,1'-binaphthyl-2,2′-dioxy moiety have been synthesised. The structure and absolute configuration of a diastereomeric palladium complex, [PdCl2{ηsu2}-((O2C20H12)PN((S)-*CHMePh)PPh2] has been determined by X-ray crystallography. The reactions of [CpRu(PPh3)2Cl] with various symmetrical and unsymmetrical diphosphazanes of the type, X2PN(R)PYY′ (R = CHMe2 or (S)-*CHMePh; X = C6H5 or X2 = O2C20H12; Y=Y′= C6H5 or Y = C6H5, Y′ = OC6H4Me-4 or OC6H3Me2-3,5 or N2C3HMe2-3,5) yield several diastereomeric neutral or cationic half-sandwich ruthenium complexes which contain a stereogenic metal center. In one case, the absolute configuration of a trichiral ruthenium complex, viz. [Cp*Ruη2-Ph2PN((S)-*CHMePh)*PPh (N2C3HMe2-3,5)Cl] is established by X-ray diffraction. The reactions of Ru3(CO)12 with the diphosphazanes (C20H12O2)PN(R)PY2 (R = CHMe2orMe; Y2=O2C20H12or Y= OC6H5 or OC6H4Me-4 or OC6H4OMe-4 or OC6H4But-4 or C6H5) yield the triruthenium clusters [Ru3(CO)10{η-(O2C20H12)PN(R)PY2}], in which the diphosphazane ligand bridges two metal centres. Palladium allyl chemistry of some of these chiral ligands has been investigated. The structures of isomeric η3-allyl palladium complexes, [Pd(η3-l,3-R′2-C3H3){η2-(rac)-(02C20H12)PN(CHMe2)PY2}](PF6) (R′ = Me or Ph; Y = C6H5 or OC6H5) have been elucidated by high field two-dimensional NMR spectroscopic and X-ray crystallographic studies.  相似文献   

2.
The results of MNDO/PM3 calculations of η5-π-C60R5M complexes (R=H and Ph; M=Tl and In) are reported. Local energy minima and geometric parameters as well as the heats of formation and ionization potentials were determined for all systems in question. The nature of chemical M—pent bonding (pent is the pentagonal face) is discussed. The results of calculations are compared with experimental data that confirm our predictions about the possibility of existence of stable cyclopentadienyl type η5-π-complexes of C60 fullerence derivatives. The stability of the C60In12 complex with theI h symmetry, in which the In atoms are coordinated to each of 12 pentagonal faces of C60 fullerene, was estimated. The energy of the In—pent bond (62.4 kcal mol−1) is close to that in C60H5In (64.5 kcal mol−1). Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 1935–1940, November, 1997.  相似文献   

3.
New complexes:Zn(Hsalox)(ox), Zn(Hsalox)(NHPh), Zn(Hsalox)(Hsal) and Zn(Hsalox)2(1,2-diMeim) have been synthesised as a result of a reaction of Zn(salox) and Zn(Hsalox)2 (where: salox 2–=OC6H4CHNO2–, Hsalox =OC6H4CHNOH) with 8-hydroxyquinoline (Hox), o-aminophenol (NH2Ph), o-hydroxybenzoic acid (H2Sal) and 1,2-dimethylimidazole (1,2-diMeim). Chemical, X-ray and thermal analyses of the complexes and their sinters have been carried out. Thermal decomposition pathways have been postulated for the complexes. The mixtures about not definite composition have been obtained as a result of a reaction of zinc(o-hydroxybenzaldoximates) with imidazole(Him) and 4-methylimidazole (4-MeHim). This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

4.
Excess molar volumes VmE for binary liquid mixtures of n-alkoxyethanols or polyethers + 2-pyrrolidinone or N-methyl-2-pyrrolidinone have been measured with a continuous dilution dilatometer at 298.15 K and atmospheric pressure as a function of composition. The alkoxyethanols are diethylene glycol monomethylether, 2-(2-methoxyethoxy) ethanol, CH3(OC2H4)2OH; diethylene glycol monoethylether, 2-(2-ethoxyethoxy) ethanol, C2H5(OC2H4)2OH; and diethylene glycol monobutylether, 2-(2-butoxyethoxy) ethanol, C4H9(OC2H4)2OH; whereas the polyethers are diethylene glycol dimethylether, bis(2-methoxyethyl)ether, CH3(OC2H4)2OCH3; diethylene glycol diethylether, bis(2-ethoxyethyl)ether, C2H5(OC2H4)2OC2H5; and diethylene glycol dibutylether, bis(2-butoxyethyl)ether, C4H9(OC2H4)2OC4H9. In all mixtures the excess molar volumes are negative and symmetric across the entire composition range. The excess volumes are fitted to the Redlich–Kister polynomial equation to obtain the binary coefficients and the standard errors. The experimental results have also been discussed on the basis of IR measurements.  相似文献   

5.
Fullerenyl radicals (FR) RC60 · and chemiluminescence (CL) are generated in the presence of O2 in C60—R3Al (R = Et, Bui) solutions in toluene (T = 298 K). The FR are formed due to the addition of the R· radical, which is an intermediate of R3Al autooxidation, to C60. Mass spectroscopy and HPLC were used to identify EtnC60Hm (n, m = 1–6), EtpC60 (p = 2–6), and dimer EtC60C60Et as stable products of FR transformations. As found by ESR, the EtC60 · radical (g = 2.0037) is also generated by photolysis of solutions obtained after interaction in the (C60— R3Al)—O2 system. In the presence of dioxygen, the FR is not oxidized but yields complexes with O2, which appear as broadening of the ESR signals. Chemiluminescence arising in the (C60—R3Al)—O2 system is much brighter (I max = 1.86·108 photon s−1 mL−1) than the known background CL (I max = 6.0·106 photon s−1 mL−1) for the autooxidation of R3Al and is localized in a longer-wavelength spectral region (λmax = 617 and 664 nm). This CL is generated as a result of energy transfer from the primary emitter 3CH3CHO* to the products of FR transformation: RnC60Hm, RpC60, and EtC60C60Et. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 205–213, February, 2007.  相似文献   

6.
Co-crystallization of melamine(MA) and sulfate results in crystalline product [(C3H7N6+)2(SO42−)] · 2H2O. The novel supramolecular complex has been characterized by elemental analysis, thermal analysis (TGA and DSC), nuclear magnetic resonance (NMR), and single crystal X-ray diffraction. X-ray crystallographic studies of the complex reveal that the title complex has a 3-D microporous structure which is linked by intense intermolecular hydrogen-bonding interactions (N–H······O, N–H······N, O–H······O) and aromatic π-π interaction, which stabilize the whole crystal framework. The TGA curve shows that the complex is stable up to 500 °C, above which its structure begins to collapse.  相似文献   

7.
The molecular and electronic structure of hypothetical complexes of unsubstituted fullerene C60 withI h symmetry and its cyclopentadienyl type derivatives were simulated by the MNDO/PM3 method taking the C60(XC[) n molecules (n=1, 2, 10, 12; X=Si, Ge, Sn) and η5-C60H5XCp (X=Ge, Sn), respectively, as example. The complexes 12η5-πC60(XCp)12 and η5-πC60XCp withI h andC 5v symmetry, respectively, were found to be the most stable compounds. The energies of the X−C60 bonds in these complexes are close to those of X−Cp bonds in bis(cyclopentadienyl) complexes XCp2 and are substantially higher than the energies of similar bonds in complexes of unsubstituted fullerene η1-πC60(XCp) and η5-πC60(XCp)+. Geometric parameters and spin densities in radicals C60XCp and biradicals C60(XCp)2 and C60H10 were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2155–2165, November, 1998.  相似文献   

8.
The molar conductivities (Λ) of solutions of n-tetrabutylammonium tetraphenylborate (NBu4BPh4) in 3-pentanone have been measured in the temperature range from 283.15 to 329.15 K. The conductance data have been analyzed using the Lee-Wheaton conductivity equation with the distance parameter (a) set at Bjerrum’s pairing distance, and the limiting molar conductivities (Λo) and the association equilibrium constants (K A) have been derived. The limiting ion conductivities (λ_±o) have been evaluated according to the method of Krumgalz. The λ+ o values have been compared with λ+ o values calculated from the empirical equation of Gill. The thermodynamic functions, Gibbs energy (Δ G A o), enthalpy (Δ H A o) and entropy (Δ S A o) for the process of ion-pair formation as well as the activation energy of the ionic movement (ΔH ) have been evaluated. The obtained results are discussed in terms of ion-ion and ion-solvent interactions.  相似文献   

9.
Excess molar enthalpies, H E, for the binary mixtures {p-xylene+(1–x) octane}, {x p-xylene+(1–x) diethyl carbonate}, {x octane+(1–x) diethyl carbonate} and the corresponding ternary system {x 1 p-xylene+x 2 octane+(1–x 1x 2) diethyl carbonate} have been measured by using a Calvet microcalorimeter at 298.15 K under atmospheric pressure. The experimental H E values are all positive for the binary and ternary mixtures over the entire composition range.  相似文献   

10.
The first γ-trimethylstannyl sulfimide, Me3Sn(CH2)3S(=NSO2Ar)C5H11-n, was synthesized by oxidative imination of Me3Sn(CH2)3SC5H11-n with ArSO2(Na)Cl (Ar=C6H4Cl-4). Oxidation of γ-trimethylstannyl sulfimide by an alkaline solution of H2O2 gave γ-trimethylstannyl sulfoximide, Me3Sn(CH2)3S(O)(=NSO2Ar)C5H11-n, and γ-trimethylstannyl sulfone, Me3Sn(CH2)3SO2C5H11-n, the latter compound resulting from hydrolysis of the arylsulfimide group. Oxidation of stannyl sulfide by hydrogen peroxide yielded γ-trimethylstannyl sulfoxide, Me3Sn(CH2)3S(O)C5H11-n (under mild conditions) or γ-trimethylstannyl sulfone (under more severe conditions). Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 371–374, February, 1997.  相似文献   

11.
Two new inclusion compounds (n-C4H9)4N+C18-H13O4 ·B(OH)3 (1) and (n-C4H9)4N+C18H13O4 (2) were prepared and characterized by X-ray crystallography. Crystal data: compound 1, monoclinic P2(1)/c, a = 1.569 9(1) nm, b = 0.995 5(6) nm, c = 2.293 3(1) nm, β = 109.962(3)°, Z = 4, and R 1 = 0.0434, wR = 0.075 9; compound 2, monoclinic C2/c, a = 1.400 5(3) nm, b = 1,282 1(2) nm, c = 1.765 7(3) nm, β = 100.388(1)°, Z = 4, and R 1 = 0.0584, wR = 0.096 6. In the crystal structure of 1, the tetramers formed by two trans-9,10-dihydro-9,10-ethanoanthracene-11,12-dicarboxylic acid (EADA) anions and two boric acid molecules were connected through O—H⋯O hydrogen bonds to generate a channel type host lattice. The tetra-n-butylammonium cations were stacked to give two columns within each channel with cross-sectional size of about 2.30 nm × 0.93 nm. In the crystal structure of 2, similar honeycomb host lattices with big size were also formed along the [101] direction by three-dimensional accumulation of EADA anions. The tetra-n-butylammonium cations were accommodated in a zigzag fashion within each channel. Translated from Acta Chimica Sinica, 2006, 64(18): 1904–1910 [译自: 化学学报]  相似文献   

12.
Abstract Sodium 4′-methoxy-5,6,7-trihydroxyisoflavone-3′-sulfonate (1) is synthesized by the sulfonation of 6-hydroxybiochanin A and its structure is characterized by elemental analysis, 1H-NMR, and IR spectroscopy. It is assembled with cobalt(II) or zinc(II), hexaquacobalt(II) bis(4′-methoxy-5,6,7-trihydroxyisoflavone-3′-sulfonate) tetrahydrate (2) and hexaquazinc(II) bis(4′-methoxy-5,6,7-trihydroxyisoflavone-3′-sulfonate) tetrahydrate (3) are obtained and characterized by IR spectroscopy. Simultaneously, their three-dimensional structures are determined by single-crystal X-ray analysis. It turns out that 2 and 3 are isomorphous and crystallize in the triclinic crystal system, space group P-1. Hydrophilic regions are defined by O–H···O hydrogen bonds involving the coordinated water molecules, the included water molecules, and sulfonate groups. Aromatic π...π stacking interactions assemble the isoflavone skeletons into columns and these columns formed hydrophobic regions. The sulfonate group is an important bridge as a structural link between the hydrophilic regions and the hydrophobic regions. Hydrogen bonds, π...π stacking interactions and the electrostatic interactions assemble 2 and 3 into three-dimensional network structures. Graphical abstract Sodium 4′-methoxy-5,6,7-trihydroxyisoflavone-3′-sulfonate (1) is synthesized and assembled with cobalt(II) or zinc(II). Hexaquacobalt(II) bis(4′-methoxy-5,6,7-trihydroxyisoflavone-3′-sulfonate) tetrahydrate (2) and hexaquazinc(II) bis(4′-methoxy-5,6,7-trihydroxyisoflavone-3′-sulfonate) tetrahydrate (3) are obtained and determined by single-crystal X-ray analysis. It turns out that 2 and 3 are isomorphous and assembled into three-dimensional network structures, characterized by hydrophilic regions defined by hydrogen bonds involving the coordinated water molecules, the included water molecules, and the sulfonate groups and by hydrophobic columns, formed by the isoflavone skeletons, interacting through π...π stacking interactions.   相似文献   

13.
Half-titanocene is well-known as an excellent catalyst for the preparation of SPS (syndiotactic polystyrene) when activated with methylaluminoxane (MAO). Dinuclear half-sandwich complexes of titanium bearing a xylene bridge, (TiCl2L)2{(μ-η5, η5-C5H4-ortho-(CH2–C6H4–CH2)C5H4}, (4 (L = Cl), 7 (L = O-2,6-iPr2C6H3)) and (TiCl2L)2{(μ-η5, η5-C5H4-meta-(CH2–C6H4–CH2)C5H4} (5 (L = Cl), 8(L = O-2,6-iPr2C6H3)), have been successfully synthesized and introduced for styrene polymerization. The catalysts were characterized by 1H- and 13C NMR, and elemental analysis. These catalysts were found to be effective in forming SPS in combination with MAO. The activities of the catalysts with rigid ortho- and meta-xylene bridges were higher than those of catalysts with flexible pentamethylene bridges. The catalytic activity of four dinuclear half-titanocenes increased in the order of 4 < 5 < 7 < 8. This result displays that the meta-xylene bridged catalyst is more active than the ortho-xylene bridged and that the aryloxo group at the titanium center is more effective at promoting catalyst activity compared to the chloride group at the titanium center. Temperature and ratio of [Al]:[Ti] had significant effects on catalytic activity. Polymerizations were conducted at three different temperatures (25, 40, and 70 °C) with variation in the [Al]:[Ti] ratio from 2000 to 4000. It was observed that activity of the catalysts increased with increasing temperature, as well as higher [Al]:[Ti]. Different xylene linkage patterns (ortho and meta) were recognized to be a principal factor leading to the characteristics of the dinuclear catalyst due to its different spatial arrangement, causing dissimilar intramolecular interactions between the two active sites.  相似文献   

14.
The integrated extinction coefficients (A) of the C≡C stretching modes in the IR spectra of 12 germylacetylenes Me3GeC≡CR are determined by the resonance interactions of substituents with the triple bond. TheA 1/2 values change linearly with change in the difference between the effective π-electron charges on the atoms at the triple bond and σ0 R constants of organic substituents R. The average value of the σ0 R constant of the Me3Ge substituent in the compounds studied is +0.06. The resonance acceptor effect of the Me3Ge substituent toward the triple bond (d,π-conjugation) is stronger than the donor effect (σ,π-conjugation). Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1569–1574, August, 1998.  相似文献   

15.
The molecular and electronic structure of hypothetical metallofullerenes In5C55 (1a) and In10C60 (2a) were simulated by the MNDO/PM3 method. Formally, heterofullerene1a is obtained from the C60 cluster by replacement of the carbon atoms at α-positions relative to one of the pentagons by In atoms, and cluster2a is obtained from the C70 cluster by replacement of the carbon atoms framing the polar pentagons of this fullerene by In atoms. Along with clusters1a and2a, their η5-π-complexes ln(η5-1a (1b) and ln2(2η5-2a) (2b) with one (1b) and two (2b) exohedral In atoms coordinated to the pentagons (pent *) isolated by In atoms were also studied. The energies of the In—pent * bonds in1b and2b are approximately equal to 104 kcal mol−1. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 880–883, May, 1998.  相似文献   

16.
Excess molar enthalpies of the ternary system {x 1 p-xylene+x 2decane+(1–x 1x 2)diethyl carbonate} and the involved binary mixtures {p-xylene+(1–x)decane}, {xp-xylene+(1–x)diethyl carbonate} and {xdecane+(1–x)diethyl carbonate} have been determined at the temperature of 298.15 K and atmospheric pressure, over the whole composition range, using a Calvet microcalorimeter. The experimental excess molar enthalpies H m E are positive for all the binary systems studied over the whole composition range. Excess molar enthalpy for the ternary system is positive as well, showing maximum values at x 1=0, x 2=0.4920, x 3=0.5080, H m,123 E=1524 J mol–1.  相似文献   

17.
18.
    
The reaction of barium carbonate with 4-nitrobenzoic acid (4-nbaH) results in the formation of a Ba(II) coordination polymer, catena-poly[[(pentaaqua)(4-nitrobenzoato-O,O’)barium(II)](μ-4-nitrobenzoato-O,O’)] 1. The polymeric compound [[Ba(H2O)5(4-nba-O,O’)](μ-4-nba-O,O’)] n 1 was characterized by elemental analysis, IR and UV-Vis spectra, weight loss studies, X-ray powder diffraction and its structure determined. In 1 five water molecules are coordinated to the central metal and one of the 4-nba ligands is bonded to Ba(II) in a bidentate manner (4-nba-O,O’) through the carboxylate O atoms. The [(pentaaqua)(4-nitrobenzoato-O,O’)barium(II)] units are linked into an infinite one-dimensional chain along b-axis with the aid of the second 4-nba anion, which functions as a bridging bidentate (μ-4-nba-O,O’) ligand. This results in nine coordination around each Ba(II) ion in the coordination polymer. A long Ba⋯Ba distance of 6.750(1) ? is observed between adjacent Ba(II) ions in the chain and the oxygen atoms of the carboxylate group and the nitro functionalities of the 4-nba ligand are involved in several O-H⋯O and C-H⋯O interactions. Dedicated to the memory of Late Prof. Bhaskar G. Maiya  相似文献   

19.
Symmetrical and asymmetrical triphenylene discotic liquid crystals with two kinds of different peripheral chains, sym-TP(OC11H23)3(O2CR)3 and asym-TP(OC11H23)3(O2CR)3, (R=CH2OC2H5, CH2OC3H7, CH2OC4H9, CH2OC5H11, C3H7, C4H9, C5H11, C6H13, C7H15) were synthesized. Their thermotropic liquid crystalline properties were studied by polarizing optical microscopy (POM) and differential scanning calorimetry (DSC). The results showed that the asymmetrical compounds had higher melting and clearing points than that of their corresponding symmetrical compounds. For the same series of compounds, TP(OC11H23)3(O2CR)3, their melting points decrease and clearing points increase gradually with the lengthening of ester chains. Most of the β-oxygen containing esters of triphenylene derivatives, TP (OC11H23)3(O2CR)3, (R=CH2OC2H5, CH2OC3H7, CH2OC4H9, CH2OC5H11), symmetrically or asymmetrically attached on triphenylene cores, have higher melting and clearing points than those of triphenylene derivatives, TP(OC11H23)3(O2CR)3, (R=C4H9, C5H11, C6H13, C7H15), with the same length of peripheral chains. The triphenylene derivatives with longer peripheral chains have shown mesophase at room temperature. __________ Translated from Chemical Research and Application, 2007, 19(10) (in Chinese)  相似文献   

20.
A series of complexes of fullerenes C60 and C70 with metal dithiocarbamates {MII(R2dtc)2}·Cm (m = 60 or 70) and metal dithiocarbamates coordinated to nitrogen-containing ligands (L), {MII(R2dtc)2)x·L}·C60 (x = 1 or 2), where M = Cu, Zn, Cd, Hg, Mn, or Fe, R = Me, Et, Prn, Pri, or Bun, L is 1,4-diazabicyclo[2.2.2]octane (DABCO), N,N′-dimethylpiperazine, or hexamethylenetetramine, were synthesized. The shape of dithiocarbamate molecules is sterically compatible with the spherical shape of C60, resulting in an efficient interaction between their π systems. The resulting compounds are characterized by a layered or three-dimensional packing of the fullerene molecules. In the C60 complexes, iron(II) and manganese(II) dithiocarbamates exist in the high-spin states (S = 2 and 5/2). The magnetic susceptibility of {MII(Et2dtc)2}2·Cm (M = Fe or Mn, m = 60 or 70) in the temperature range of 200–300 K is described by the Curie-Weiss law with Θ = −250 and −96 K and with maxima at 110 and 46 K, respectively, which is indicative of a strong antiferromagnetic spin coupling between MII. The Weiss constants for the [{MII(Et2dtc)2}2·DABCO]·C60·(DABCO)2 complexes (M = Fe or Mn) are 1.7 and 0.3 K, respectively. The magnetic moments of the complexes containing Fe and Mn dithiocarbamates slightly increase at temperatures below 50 and 35 K, respectively, which is evidence of the ferromagnetic spin coupling between MII in {MII(Et2dtc)2}2·DABCO. Single crystals of the complexes exhibit low dark conductivity (10−10–10−11 S cm−1). The visible light irradiation of these crystals leads to an increase in the photocurrent by two–three orders of magnitude. The photogeneration of free charge carriers in the complexes occurs both due to the photoexcitation of metal dithiocarbamate (CuII(Et2dtc)2) and through the charge transfer from metal dithiocarbamate (MII(Et2dtc)2, M = Zn or Cd) to C60. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2072–2087, November, 2007.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号