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1.
Abstract
The complex [Fe(C6H4N2S2)3]2+(NO3−)2 was prepared from the reaction of 4,4′-bithiazole with Fe(NO3)3·9H2O in methanol. It was characterized by IR, UV-Vis, luminescence, 1H NMR and 13C NMR spectroscopy, and X ray crystallography. The structure was solved in the orthorhombic space group P212121 with a = 12.1500(5), b = 12.8434(6), c = 16.2222(7) ?, V = 2531.43(19) ?3, Z = 4, and with wR 2 = 0.0897. 相似文献2.
Ya?ar Dürüst Muhammet Y?ld?r?m Chris F. Fronczek Frank R. Fronczek 《Monatshefte für Chemie / Chemical Monthly》2012,38(2):127-138
Abstract
Eleven novel dihydropyrrolo[3,4-c]pyrazole derivatives were obtained by the reaction of chiral (1R)-N-(1-phenylethyl)maleimide and C,N-aryl-substituted nitrilimines. The reaction afforded the cycloadducts as a regioisomeric mixture which can be separable in some cases. The structure and stereochemistry of cycloadducts were assigned on the basis of infrared (IR), 1H and 13C nuclear magnetic resonance (NMR), mass and X-ray spectra, optical rotation measurements, and CHN analyses. 相似文献3.
Florian Kraus 《Monatshefte für Chemie / Chemical Monthly》2012,41(8):1097-1100
Abstract
Hexaamminecadmium(II) fluoride monohydrate (1:1) [Cd(NH3)6]F2·H2O was synthesized from CdF2 and liquid ammonia in open reaction vessels, so that moisture from the air was in contact with the solvent. The compound crystallizes in the chiral space group P3121- (No. 152) in the form of needle-shaped, colorless crystals with a = 6.8974(1) ?, c = 17.7156(5) ?, V = 729.89(3) ?3, and Z = 3. 相似文献4.
Franc Perdih 《Monatshefte für Chemie / Chemical Monthly》2012,42(8):1011-1017
Abstract
Copper(II) bis(pentane-2,4-dionato-κ2 O,O′) compounds with 2-pyridone (1) and 3-hydroxypyridine (2) were prepared by the reaction of bis(pentane-2,4-dionato-κ2 O,O′)copper(II) with selected ligands. The coordination of Cu(II) in both compounds is square pyramidal with the fifth coordination site occupied by the carbonyl oxygen atom of the 2-pyridone ligand in 1 and by the nitrogen atom of 3-hydroxypyridine in 2. The X-ray crystallographic studies revealed different crystal aggregation influenced by the ability of the 2-pyridone ligand to act as a hydrogen bond donor and acceptor, and 3-hydroxypyridine acting only as a hydrogen bond donor. Intermolecular N–H···O hydrogen bonding forms dimers in 1 and infinite chains in 2. Three-dimensional aggregation is achieved by π–π interactions and C–H···π (arene) hydrogen bonding. 相似文献5.
Emanuel Makrlík Petr Vaňura Jan Budka Pavel Selucky 《Monatshefte für Chemie / Chemical Monthly》2010,287(3):31-33
Abstract
From extraction experiments in the two-phase water–nitrobenzene system and γ-activity measurements, the stability constants of the tetraethyl p-tert-butyltetrathiacalix[4]arene tetraacetate (cone)·M+ complexes (M+ = Li+, H3O+, NH4 +, Ag+, or K+) were determined in water-saturated nitrobenzene. It was found that these constants increase in the cation order NH4 + < K+ < H3O+ < Ag+ < Li+ < Na+. 相似文献6.
Emanuel Makrlík Ji?í Dybal Jan Budka Petr Vaňura 《Monatshefte für Chemie / Chemical Monthly》2009,287(1):1155-1158
Abstract
From extraction experiments and γ-activity measurements, the extraction constant corresponding to the equilibrium H3O+(aq) + 1·Na+(nb) \leftrightarrows \leftrightarrows 1·H3O+ (nb) + Na+ (aq) taking place in the two-phase water–nitrobenzene system (1 = p-tert-butylcalix[4]arenetetrakis(N,N-dimethylacetamide); aq = aqueous phase, nb = nitrobenzene phase) was evaluated as log K ex (H3O+, 1·Na+) = −0.1 ± 0.1. Further, the stability constant of the 1·H3O+ complex in water-saturated nitrobenzene was calculated for a temperature of 25 °C as log β nb (1·H3O+) = 10.9 ± 0.2. By using quantum mechanical DFT calculations, the most probable structure of the 1·H3O+ cationic complex species was derived. In this complex, the hydroxonium ion H3O+ is bound partly to one phenoxy oxygen atom and partly to two carbonyl oxygens of 1 by strong hydrogen bonds and obviously by other electrostatic interactions. 相似文献7.
Abstract
Tridentate Schiff base ligands L1 and L2, derived from the condensation of 2-hydroxy-3-methoxybenzaldehyde (L) with 2-aminoethanol or 2-aminobutan-1-ol, react with nickel chloride, azide, or thiocyanate to give rise to two dinuclear complexes of formulas [Ni2(L)(L1)2N3]·H2O (1), [Ni2(L2)3(μ1,1-N3)]·2H2O (2), and one tretranuclear complex [Ni2(L2)2(NCS)]2(C2H5OH)2 (3), where L1 = HOCH2CH(C2H5)NCHC6H3(O−)(OCH3) and L2 = HO(CH2)2NCHC6H3(O−)(OCH3). We have characterized these complexes by analytical, crystal structures, and variable temperature magnetic susceptibility measurements. The magnetic properties of the complexes are studied by magnetic susceptibility (χM) vs. temperature measurements. The χM T vs. T plots reveal that compounds 1, 2 and 3 are ferromagnetically coupled. 相似文献8.
Abstract
A series of cyanonitrovinyl neonicotinoids were designed and synthesized via five steps in about 35% overall yields. All compounds were structurally characterized by 1H nuclear magnetic resonance (NMR), 13C NMR, infrared (IR), and high-resolution mass spectrometry (HRMS), and single-crystal X-ray diffraction analysis of 2-[1-[(6-chloropyridin-3-yl)methyl]-2-imidazolidinylidene]-2-nitroacetonitrile revealed that the double bond is (E)-configured. The preliminary agriculture bioassay indicated that one compound exhibited moderate insecticidal activity against pea aphid. 相似文献9.
Feng Yu Jingjie Zhang Yanfeng Yang Guangzhi Song 《Journal of Solid State Electrochemistry》2010,14(5):883-888
Composite Li3V2(PO4)3/C cathode material can be synthesized by spray-drying and carbothermal method. The monoclinic-phase Li3V2(PO4)3/C was prepared with the process of double spray drying at 260 °C and subsequent heat treatment at 750 °C for 12 h. The results
indicate that the Li3V2(PO4)3/C presents large reversible discharge capacity of 121.9 mA h g−1 and charge capacity of 131.8 mA h g−1 at the current density of C/5, good rate capability with 61.1 mA h g−1 at 20C, and excellent capacity retention rate close to 100% at various current densities in the region of 3.0–4.3 V. 相似文献
10.
Abstract
UV–visible spectral observations indicate that the J-aggregation of protonated meso-tetra(4-sulfonatophenyl)porphyrin ([H2TSPP]2+) under acidic conditions is completely inhibited by the π–π counteraction between 1-butyl-pyridinium tetrafluoroborate ([bpy]BF4) and [H2TSPP]2+. The studies also suggest that the intermolecular π–π force is of relative importance for the J-aggregates of [H2TSPP]2+ and the intermolecular electrostatic force for the H-aggregates. 相似文献11.
Aliakbar Dehno Khalaji Karla Fejfarova Michal Dusek Debasis Das 《Monatshefte für Chemie / Chemical Monthly》2012,41(3):753-761
Abstract
2-Cyano-3-(2,5-dimethoxyphenyl)acrylic acid and its novel mononuclear square-planar copper(II) complex dipiperidinium tetrakis[2-cyano-3-(2,5-dimethoxyphenyl)acrylic acid]copper(II) ((Pip-H+)2[CuL4]2−) were synthesized and characterized by elemental analyses, FT–IR, UV–Vis spectroscopy, and thermogravimetric analysis. Moreover, the ligand was characterized by 1H and 13C NMR spectroscopy. The structures of the ligand and its copper(II) complex were confirmed by single-crystal X-ray crystallography. Whereas the ligand crystallizes in the triclinic space group Pī with unit cell parameters a = 4.6911(2) ?, b = 9.0181(4) ?, c = 13.7084(6) ?, α = 74.946(4)°, β = 87.152(4)°, γ = 89.220(4)°, V = 559.34(4) ?3, and Z = 2, the complex crystallizes in the orthorhombic space group Pccn with unit cell parameters a = 27.5486(5) ?, b = 12.9484(2) ?, c = 15.8822(3) ?, V = 5,665.34(17) ?3, and Z = 4. 相似文献12.
Bhawana Gupta Nidhi Kalgotra Savit Andotra Sushil K. Pandey 《Monatshefte für Chemie / Chemical Monthly》2012,39(5):1087-1095
Abstract
O-Tolyl/benzyl dithiocarbonates, ROCS2Na (R = o-, m-, or p-CH3C6H4–, and –CH2C6H5), were synthesized and characterized. These new ligands reacted with PCl3/POCl3 in refluxing toluene which resulted in the formation of phosphorus(III) and phosphorus(V) tolyl/benzyl dithiocarbonates corresponding to [(ROCS2) n PCl3−n ] and [(ROCS2) n POCl3−n ] (R = o-, m-, or p-CH3C6H4–, and –CH2C6H5; n = 1, 2, 3). These pale yellow liquid compounds were characterized by IR, mass, and NMR (1H, 13C, and 31P) spectral studies, which suggest the dithiocarbonate ligands bind in a monodentate mode leading to P–S–C linkages in these derivatives. 相似文献13.
Gourisankar Panda Md. Selim Rupali Pal Kalyan K. Mukherjea 《Monatshefte für Chemie / Chemical Monthly》2009,33(2):281-286
Abstract
The interaction of cobalt(II)-glutathione (CoGSH) with deoxyribonucleic acid (DNA) has been studied by UV–vis, fluorescence, circular dichroism (CD), thin-film infrared (IR), and viscometric techniques. From the UV-spectroscopic method, binding constant (K b) was determined and was found to be 2.3 × 106 M−1. In fluorimetric analysis, the quenching of fluorescence intensity of DNA bound to ethidium bromide (EB) was investigated. The Stern–Volmer quenching constant (K sv) was also estimated from this study and was found to be 2.8 × 106 M−1at 37 °C. The solution CD spectra of DNA and DNA–CoGSH indicate that in each case, DNA exists in the ‘B’ conformation and suggested an intercalative binding mode. Thin-film IR data also reveal that DNA attains the ‘B’ family of conformations after interaction with CoGSH complex. The increase in DNA viscosity in the presence of CoGSH complexes is attributed to the lengthening of DNA helix due to intercalation. 相似文献14.
Jian-zhang Li Lei Wei Fa-Mei Feng Jun Zeng Sheng-ying Qin 《Transition Metal Chemistry》2010,35(4):463-468
Abstract
Schiff base Co(II) complexes, CoL21–CoL26 with aza-crown or morpholino pendants were synthesized. The oxygenation constants (KO2) of these complexes in MeOCH2CH2OMe solution were measured over the range of −5 to 25 °C, and the thermodynamic parameters (∆H 0, ∆S 0) for oxygenation were calculated based on these KO2 values. The effects of different substituents on the Schiff base ligand with respect to the modulation of O2-binding capability were explored. The results indicate that the dioxygen affinities of the Co(II) complexes are much more enhanced by aza-crown pendants than that by morpholino pendants, and the O2-binding capabilities of the aza-crown pendants complexes can also be enhanced by adding Na+ cations. 相似文献15.
Ulrike Pfannenschmidt Ute Ch. Rodewald Rainer P?ttgen 《Monatshefte für Chemie / Chemical Monthly》2011,41(2):219-224
Abstract
The rhodium-rich phosphides RERh6P4 (RE = Sc, Yb, Lu) were synthesized from the constituent elements in bismuth fluxes and their structures were refined from X-ray single-crystal diffractometer data: P3, a = 6.968(2), c = 3.666(2) ?, wR (F 2) = 0.0481, 895 F 2 for ScRh6P4; a = 6.971(1), c = 3.673(1) ?, wR (F 2) = 0.0614, 700 F 2 for YbRh6P4; a = 6.971(2), c = 3.682(1) ?, wR (F 2) = 0.0828, 722 F 2 for LuRh6P4 with 37 variables per refinement. All three crystals are twinned. The twinning and the structural relationship with the aristotype LiCo6P4, space group P[`6]m2P\bar 6m2 are discussed on the basis of a group–subgroup scheme. The RERh6P4 phosphides belong to the large number of metal-rich compounds with a metal-to-phosphorus ratio near 2:1. The isolated phosphorus atoms have trigonal prismatic metal coordination by RE and Rh atoms. The high rhodium content leads to a pronounced rhodium substructure (278–293 pm Rh–Rh in ScRh6P4). From a geometrical point of view, the RERh6P4 structures can be viewed as intergrowth variants of slightly distorted ThCr2Si2-related slabs as realized for KRh2P2. 相似文献16.
Francesco Crea Concetta De Stefano Demetrio Milea Silvio Sammartano 《Monatshefte für Chemie / Chemical Monthly》2010,39(2):511-520
Abstract
The results of an investigation on the interactions between phytate ion (myo-inositol hexaphosphate, Phy) and some lanthanoid cations (La3+, Nd3+, Sm3+, Dy3+, and Yb3+) are reported. The stability constants of various LnH j Phy species (Ln = generic lanthanoid) were determined by potentiometry (ISE-H+ glass electrode) in NaClaq at I = 0.15 mol dm−3 and t = 25 °C, and the corresponding formation enthalpies by calorimetric titration. The thermodynamic data obtained were used to provide a speciation scheme for the lanthanoid(III)–phytate systems at different temperatures. The sequestering ability of this ligand toward Ln3+ was also evaluated by calculation of pL50 values (the total concentration of ligand necessary to bind 50% of a cation present in trace amounts) under different conditions, and equations were formulated to model their dependence on temperature and pH. 相似文献17.
Abstract
Cholesterol complexes with tri-n-butyl phosphate, tri-n-octylamine, N,N-dimethylacetamide, and cyclohexanone in benzene and toluene solutions were studied using conventional IR spectroscopy. The spectra were recorded in the region of fundamental OH stretching (3,700–3,100 cm−1) at 298 K. The experimental spectra were resolved into bands corresponding to the cholesterol monomer and particular oligomeric and complex species. The formation constants of complexes were determined from the-least squares plots of the linearized expressions of Bjerrum’s formation function. The stoichiometry of complexes was also identified in this way. The identification of the particular resolved bands was performed from their location, and from the dependence of their intensity on the cholesterol monomer and free base concentration. 相似文献18.
Chao Xu Jing-Jing Zhang Taike Duan Quan Chen Qian-Feng Zhang 《Journal of Cluster Science》2010,21(4):813-823
Abstract
Reaction of the [Me4N]2[Cd(SPh-4-Me)4] with two equivalents of [M(PPh3)2NO3] afforded the neutral linear trinuclear complexes [Cd(μ-SPh-4-Me)4{M(PPh3)2}2] (M = Cu 1, Ag 2) in which two [M(PPh3)2]+ fragments chelate with the opposite edges of a tetrahedral [Cd(SPh-4-Me)4]2− moiety via the sulfur atoms of the Me-4-PhS− species. Treatment of [Sn(SPh)4] with two equivalents of [Ag(PPh3)2NO3] gave the neutral linear trinuclear complex [Sn(μ-SPh)6(AgPPh3)2] (3) that is composed of a central distorted SnS6 octahedron sharing two opposite planes with two slightly distorted AgS3P tetrahedrons. Complexes 2 and 3 are air and optically stable. Their nonlinear optical absorption and refraction were investigated under the same conditions. The nonlinear optical absorption and refraction of complex 2 were determined to be α 2 = 3.11 × 10−11 m/W and n 2 = 4.15 × 10−12 esu, respectively. The nonlinear optical absorption and refraction of complex 3 were determined to be α 2 = 8.36 × 10−11 m/W and n 2 = 1.47 × 10−11 esu, respectively. 相似文献19.
Ming-Lai Fu Norma L. Rangel Richard D. Adams Jorge M. Seminario 《Journal of Cluster Science》2010,21(4):867-878
Abstract
Thiacalix[4]arenes are a unique family of polydentate ligands that offer a combination of four soft sulfur atoms together with four hard phenol oxygen atoms for binding to metal ions. In this study, the tetranuclear cadmium (II) complex Cd4II(tca)2·1.5CH2Cl2 (tca4− = tetra-anionic p-tert-butylthiacalix[4]arene) (1) was synthesized by reaction of a deprotonated p-tert-butylthiacalix[4]arene and various CdII salts. The structure of 1 was established by single crystal X-ray diffraction analysis. The neutral complex 1 contains a square arrangement of four cadmium (II) ions sandwiched between two tca4− ligands that have a ‘cone’ conformation similar to that of the free ligand. The absorption and emission properties of the free ligand H4tca and complex 1 have been recorded and explained by DFT calculations of the molecular orbitals and electronic transitions between them. 相似文献20.