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1.
Reactions of TlCl3 with picolinic acid (Hpic), nicotinic acid (Hnic), isonicotinic acid (Hinic) and 3-hydroxy-picolinic acid (H3hpic) afford the isolation of new chlorothallium(III) complexes. The compounds are characterized by IR, Raman and multinuclear NMR (1H,13C,205Tl). The molecular structures of [TlCl2(pic)(Hpic)]·0.5H2O (1), [TlCl2(nic)(Hnic)] (2), [TlCl(inic)2]·0.6C2H5OH (3) and [TlCl(3hpic)2(h3hpic)] (4) are determined by single-crystal X-ray diffraction. A distorted octahedral TlCl2N2O2 core containing the O,N-chelating ligands is achieved in the monomeric complex 1. The coordination polyhedron in compounds 2–4 is pentagonal bipyramidal, i.e. TlCl2NO4 in 2, and TlClN2O4 in 3 and 4, respectively. O,O′,N-Bridging ligands result in a polymer chain for 2 and a three-dimensional polymeric association in 3, while compound 4 is monomeric (O, N-and O,O-chelating ligands).  相似文献   

2.
Dehydrohalogenation and metallation of boranato-bis-trimethylphosphonium salts (1), using two equivalents of a lithiumalkyl in tetrahydrofuran, leads to a solvated organolithium reagent H2B[(CH3)2PCH2]2Li (3) which can be converted into a 1:1n1-complex with tetramethylethylenediamin (4).3 reacts with anhydrous metal(II) halides to form spirocyclic coordination compounds of the type H2B[(CH3)2PCH2]2 M[CH2P(CH3)2]2BH2 (5–9,M=Be, Mg, Zn, Cd, Hg). The reaction of [(CH3)3PBH2P(CH3)3]Br (1) with lithium tetramethylmetalates Li[M(CH3)4],M=Al, Ga, on heating in the absence of a solvent affords the metallocycles H2B[(CH3)2PCH2]2 M(CH3)2 (10, 11) with evolution of methane. The products can be sublimed from the reaction mixture. The proposed structures of the new compounds, with tetrahedrally coordinated central atoms and strong covalent metal-carbon interactions, are supported by mass, IR and1H,7Li,11B,13C, and31P NMR spectra. Compound9 represents a rare case of a tetracoordinate organomercurial, compound5 is the first nonionic tetraalkylberyllate.
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3.
Summary NMR-spectroscopic investigations of substituted dithiocarbacinic acid derivatives show the existence of configurational isomers relative to the C=N double bond, but no tautomerism. We applied chemical shift differences in the1H-,13C- and15N-NMR-spectra, N - H and C - H coupling constants and NOE difference measurements in the solvents CDCl3,DMSO-d 6 and partly CD3OD in order to discriminate between the isomers and to determine the configurational composition. Compounds4 and5 exist asE-isomers in all solvents, compounds1, 2 and3 as a mixture ofE/Z-isomers. InDMSO-d 6 theE-form is the preferred isomer.
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4.
The molecular structure and conformational mobility of methyl and tert-butyl esters of peracetic acid AcOOR (R = Me (1), But (2)) were studied by the ab initio MP4(SDQ)//MP2(FC)/6-31G(d,p) method and density functional B3LYP/6-31G(d,p) approach. The B3LYP calculated equilibrium conformations of the molecules are characterized by the C-O-O-C torsion angles of 93.6° (1) and 117.0° (2). Structural features of the molecules under study and a distortion of tetrahedral bond configuration at the Cα atom were explained using the natural bonding orbital approach. The standard enthalpies of formation of AcOOMe (−328.5 kJ mol−1) and AcOOBut (−440.4 kJ mol−1) were determined using the G2 and G2(MP2) computational schemes and the isodesmic reaction approach. The transition state of AcOOMe decomposition into AcOOH and formaldehyde was calculated (E a = 122.8 kJ mol−1). The thermal effects of homolytic decomposition of the peroxy esters following a concerted mechanism (Me· + CO2 + ·OR) and simple homolysis of the peroxide bond (AcO· + ·OR) were found to be 97.5±0.3 and 155.1±0.3 kJ mol−1, respectively. At temperatures below 400 K, the most probable decomposition mechanism of peroxy esters 1 and 2 involves simple homolysis of the O-O bond.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2021–2027, October, 2004.  相似文献   

5.
N-Benzylmorpholine,-piperidine, and-pyrrolidine (1A-C, resp.) are oxidised by RuO4 (generated in situ) at both endocyclic and exocyclic (benzylic) N—α-methylene positions to afford lactams (and dioxo-derivatives) and benzaldehyde (and benzoyl derivatives), respectively. The N-oxides of 1A-C, formed by a minor side reaction, are not involved as intermediates. Control experiments showed the transient formation of endo- and exocyclic iminium cations trapped with NaCN as the corresponding nitriles. The proposed course of the RuO4-mediated oxidation of 1A-C involves the consecutive steps 1⇒iminium cations+cyclic enamine⇒oxidation products. The endocyclic/exocyclic regioselectivity of the oxidation reaction lies between 0.8 (for 1A) and 2.1 (for 1B). The amine cation radical and the N-α-C· carbon-centered radical seem not to be involved.  相似文献   

6.
Liquid state, high resolution 13C NMR spectroscopy and mass spectrometry were used to study the composition and structure of soil organic matter (SOM) using soil extracts from two long-term experiments at the Rothamsted Experimental Station. Both one- and two-dimensional NMR techniques were applied. 13C NMR sub-spectra of the CH n (n=0...3) groups, obtained by the Distortionless Enhancement by Polarisation Transfer (DEPT) technique, were used for the elucidation of the qualitative and quantitative composition of humic and fulvic acids in the soils. The chemical structure of SOM was further analysed at the molecular level through Fast Atom Bombardment Mass Spectrometry (FABMS) and Gas Chromatography-Mass Spectrometry (GC/MS). Humic and fulvic extract results were not only compared to each other, but also to the solid state 13C NMR results for the complete soil sample.  相似文献   

7.
The dependence of the fluorescence constantsk f n and the adiabatic twisting constantsk tpof the S1-State upon the solvent polarity, the capacity of hydrogen-bonding, as well as the solvent viscosity, were investigated for donor-acceptor substitutedtrans-stilbenes [4-dimethylamino-4-cyano-stilbene (1 g), 4-dimethylamino-4-diphenylphosphinyl-stilbene (1 b), 4-dimethylamino-4-brom-stilbene (1 h) and 4-dimethylamino-4-methoxistilbene (1 k)] by using the multiparameter model. An increase of the solvent polarity results in the decrease of the fluorescence ratek f n for all these compounds. The specific interaction between the strongly polar stilbenes such as1 g and1 b and a solvent leads to additional decrease ink f n but in the case of a relatively weak polar compound1 k to its growth. The linear combination of universal and specific solvent-solute interactions yields distinct relations fork tp. Both interactions have an influence onk tpfor1 g,1 b, and1 k to an equal degree. The twisting observed for1 g and1 b due to the interaction with solvent is hindered, however it is being supported for1 k. The influence of the investigated small range of viscosity onk tpat simultaneous variable solvent polarity (pure solvent) is only visible for the weak polar1 k. In the other cases the effect of solvent-polarity is predominant.The viscosity dependence ofk tpwas also experimentally proved for1 g,1 b and1 k by applying the obtained different dimethylformamid-acetonitril mixtures. According previous results the radiationless deactivation process is caused by twisting around ethyl-bonding, thereforek tpevidently decreases with an increase of viscosity.
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8.
The reaction of OsCl2(PPh3)3 with [nido-7-R1-8-R2-C2B9H10]K+ produced a series of new exo-nido-osmacarborane complexes exo-nido-5,6,10-[Cl(Ph3P)2Os]-5,6,10-(-H)3-10-H-7-R1-8-R2-7,8-C2B9H6 (1: R1 = R2 = H; 2: R1 = R2 = Me; 3: R1 = R2 = PhCH2; 4: R1 + R2 = 1,2-C6H4(CH2)2; 5: R1 = H, R2 = Me) in which the osmium-containing group is linked to the nido-carborane ligand through three two-electron three-center bonds. Compounds 15 are formed as mixtures of symmetric (a) and asymmetric (b) isomers; pure symmetric isomers 2a and 4a were isolated by fractional crystallization, and the mixture of isomers 3a, was quantitatively separated into individual compounds 3a and 3b by column chromatography on silica gel. Detailed analysis of the 31P{1H}, 1H, 11B NMR spectra of 1a,b5a,b and 2D 1H-1H{11B} and 11B{1H}-11B{1H} NMR spectra of 3a and 3b was performed. The structures of isomers 2a and 4a were confirmed by an X-ray diffraction study. According to the NMR and X-ray diffraction data, the isomerism of exo-nido-complexes 1a,b5a,b is actually the cistrans-isomerism of ligand arrangement in the octahedral coordination of the Os atom.  相似文献   

9.
Labelled acetyl-benzoylcarbene (13) formed by photolytic nitrogen elimination from [2-13C]1-phenyl-2-diazo-1,3-butadione (8) rearranges in the presence of ethanol to ethyl 2-phenylacetoacetate (26%) and ethyl 2-benzoylpropionate (74%). The13C-labelling in ethyl 2-phenylacetoacetate is found to the extend of ca.58% in the ester carbonyl function (20) and to ca. 42% in the adjacent tertiary carbon atom (21). This proves the isomerisation of carbene13 to carbene11 via the intermediate acetyl-phenyloxirene (12). The [1-13C]-labelled ester20 is formed by acetyl migration in11 to the ketene16 and subsequent addition of ethanol. In contrast, ethyl 2-benzoylpropionate is exclusively generated by migration of the methyl group in carbene13 since it contains the complete13C-labelling at the tertiary carbon atom (22).
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10.
Deprotonation of 3,4-dimethyl-3-pyrrolin-2-on (1) int-butyl alcohol/potassiumt-butoxide solutions takes place on the N atom, as shown by1H/2H exchange andpK a determinations of1 (pK=17.1), 1,3,4-trimethyl-3-pyrrolin-2-one (pK a =17.6), and 3,4-dimethyl-5-methoxy-2H-pyrrole (pK a =16.7). The SCF-MO approximation MINDO/3 indicates, however, that in the gas phase deprotonation of1 should occur at the C atom.
1.Mitt.:Ribó, J. M., Trull, F., Mh. Chem.110, 201 (1979).  相似文献   

11.
Treatment of 2- and 4-amino-3-(tert-butyl-NNO-azoxy)pyridines with nitrating agents (N2O5or NO2BF4) afforded the first representatives of pyridoannelated 1,2,3,4-tetrazine di-N-oxides, viz., pyrido[2,3-e][1,2,3,4]tetrazine 1,3-dioxide (9), 7-nitropyrido[2,3-e][1,2,3,4]tetrazine 1,3-dioxide (10), and pyrido[3,4-e][1,2,3,4]tetrazine 2,4-dioxide (11). These compounds were studied by 1H, 13C, and 14N NMR spectroscopy. The 1:1 complex of compound 10 with benzene was studied by X-ray diffraction analysis.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2471–2477, November, 2004.  相似文献   

12.
A new flavonol derivative 3, 8-dihydroxy-10-methoxy-5-H-isochromeno[4, 3-b]chromen-7-one (1) together with four known compounds, glutinone (2), luteolin (3), acacetin 7-O-α-L-rhamnopyranosyl- (1→6)-β-D-glucopyranoside (4), and rutin (5) were isolated from the dried roots of Fagopyrum dibotrys. Their structures were determined by UV, IR, MS, 1H, and 13C NMR spectroscopic analysis, including 2D NMR. Published in Khimiya Prirodnykh Soedinenii, No. 6, pp. 567–568, November–December, 2008.  相似文献   

13.
Addition of amines to dibenzylidene sulfamide1 a yields the correspondingSchiff bases3 a, b and monobenzylidene sulfamide2. Reaction of several dibenzylidene sulfamides1 with various lithium-amides gives N1-substituted N2-benzylsulfamoyl-benzamidines7 a-k via an intramolecular hydride transfer reaction, whereas by treatment of1 a with sodium amide 2-benzyl-3,5-diphenyl-3,4-dihydro-2H-1,2,4,6-thiatriazine-1,1-dioxide8 is obtained, which on hydrolysis yields9 and11. Alkylation products are described, the isomeric products12a/13a and12b/13b are isolated, their structures are confirmed by synthesis, IR and NMR-spectra.
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14.
A convenient methodology was developed for a very accurate calculation of 13C NMR chemical shifts of the title compounds. GIAO calculations with density functional methods (B3LYP, B3PW91, PBE1PBE) and 6-311+G(2d,p) basis set predict experimental chemical shifts of 3-ethynylcyclopropene (1), 1-ethynylcyclopropane (2) and 1,1-diethynylcyclopropane (3) with high accuracy of 1–2 ppm. The present article describes in detail the effect of geometry choice, density functional method, basis set and effect of solvent on the accuracy of GIAO calculations of 13C NMR chemical shifts. In addition, the particular dependencies of 13C chemical shifts on the geometry of cyclopropane ring were investigated.  相似文献   

15.
The crystal structure of Pyridine-2,6-dithio-carbomethylamide (PDTA) is described: C9H11N3S2, monoclinic, P21/c,Z=4,a=6.000 (1) Å,b=8.840 (1) Å,c=21.452 (1) Å, =105.47 (1)o,d x=1.47 gcm–3. The structure was solved with direct methods and refined to a conventionalR-factor of 0.047. The molecule is nearly planar in the crystal. There are possibly weak intramolecular H-bonds between the two amide nitrogens and the pyridine nitrogen and intermolecular H-bonds between two amide nitrogens and one thioamide sulfur atom. The IR andRaman spectra ofPDTA and deuteratedPDTA are discussed.
Kristallstruktur und Schwingungsspektren von Pyridin-2,6-dithiocarbomethylamid
Zusammenfassung Die Kristallstruktur von Pyridin-2,6-dithiocarbomethylamid (PDTA) wurde bestimmt: C9H11N3S2, monoklin, P21/c,Z=4,a=6,000 (1) Å,b=8,840 (1) Å,c=21,452 (1) Å, =105,47 (1)o,d x=1,47 gcm–3. Das Phasenproblem wurde mittels direkter Methoden gelöst und die Struktur bis zu einemR-Faktor vonR=0,047 verfeinert. Das Molekül ist im Kristall nahezu planar. Das Vorliegen schwacher intramolekularer Wasserstoffbrücken zwischen den beiden Thioamid-Stickstoffatomen und dem Pyridinstickstoff sowie intermolekularer Wasserstoffbrücken zwischen Thioamid-Stickstoff- und Thioamid-Schwefelatomen wird postuliert. IR- undRaman-Spektren vonPDTA und deuteriertemPDTA werden diskutiert.
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16.
Summary The two title compounds12b and13b have been prepared by direct oxidation of the corresponding 10-oxo-19-norcolcalciferol derivatives3c and4c withMCPBA. The generation of12b and13b by treatment of the 7 epoxidized ethylisoxazolin adducts of 5Z- and 5E-cholecalciferol8a,8b and9a,9b with Mo(CO)6 failed, since besides the retroaldol cleavage of the heterocycle a deoxygenation of the oxirane with retention of configuration to the 7 double bond occurs.
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17.
在微波溶剂热中,三环已基氢氧化锡、氧化双(三((2-甲基-2-苯基)丙基)锡)与吡啶-2,3(5)-二甲酸反应,合成了3个双核二(有机锡)吡啶-2,3(5)-二甲酸酯:Py(CO)2(SnR32(MeOH) n(R:Cy,n=1(1),2(2);R:PhCMe2CH2,n=0(3)),对它们的组成和结构进行了元素分析、IR、(1H,13C,119Sn) NMR和X射线晶体衍射分析表征,化合物中心锡与配基原子构成畸形四/六面体构型,由于氢键作用,化合物1形成一维链,2形成二维34元大环网状结构。化合物对人结肠癌(HT-29)、肝癌细胞(HepG2)、乳腺癌(MCF-7)、鼻咽癌(KB)和肺癌细胞(A549)的增殖有较强的抑制作用。  相似文献   

18.
Summary The absorption bands of the C=O Stretching vibrations of a series of thirty-nine substitutedZ-3-methylene phthalides (1a-s, 2a-h, 3a-f, 4a-c, and5a-c) were measured in CHCl3 and CCl4. The two-levelFermi resonance effect on the infrared spectra of the above compounds was investigated after deconvolution and band separation. The wave numbers of the unperturbed fundamental C=O stretching vibrations exhibit excellent linear correlations withHammet's constants of substituents and13C NMR chemical shifts of the C=O group.
Fermi-Resonanz in substituiertenZ-3-Methylenphthaliden
Zusammenfassung Die Absorptionsbanden der C=O-Streckschwingung von 39 substituiertenZ-3-Methylenphthaliden (1a-s, 2a-h, 3a-f, 4a-c und5a-c) wurden in CHCl3 und CCl4 vermessen. Durch Dekonvolution und Bandentrennung konnte der EinflußFermi-Resonanz auf die Infrarotspektren der obengenannten Verbindungen untersucht werden. Die Wellenzahlen der ungestörten C=O-Streckschwingungen ergeben ausgezeichnete lineare Korrelationen mit denHammetschen Substituentenkonstanten und den13C-NMR-Verschiebungen der Carbonylgruppe.
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19.
Three new compounds, 4-hydroxymethylene-7-(9,9,13-trimethylcyclohexyl)-heptanyl-3′,7′,7′-trimethylcyclohexa-2′,4′-dien-1′-oate (1), 1-(n-hexadec-7-enoxy)-6-(n-octadecanoxy)-β-D-glucopyranoside (2), and (Z)-12-hydroxy-9-octadecenoic acid-12-β-D-glucopyranoside (3), along with the known compound hexacosanoic acid (4), were isolated and identified from the rice hulls of Oryza sativa. Their structures were elucidated by 1D and 2D NMR spectroscopic techniques (1H-1H COSY, 1H-13C HETCOR, DEPT) aided by EIMS, FABMS, HRFABMS, and IR spectra. Published in Khimiya Prirodnykh Soedinenii, No. 4, pp. 344–347, July–August, 2007.  相似文献   

20.
Abstract  The solvothermal reactions of copper(I) tert-butylthiolate (CuS t Bu) with 1/3 equiv. of dppe [dppe = bis(diphenylphosphino)ethane] or bix [bix = 1,4-bis(imidalzole-1-ylmethyl)benzene] in CH3CN led to the formation of two cluster-based coordination polymers [(CuS t Bu)4(dppe)] n (1) and [(CuS t Bu)6(bix)] n (2). Single-crystal X-ray diffraction studies reveal that 1 and 2 feature 1D zigzag polymeric chains which contain rare (CuS t Bu)4 or (CuS t Bu)6 clusters as connecting junctions and dppe or bix as linkers. The title compounds show optical transitions with band gaps of ∼3.18 eV for 1 and ∼2.81 eV for 2. Compounds 1 and 2 exhibit strong photoluminescence with the peaks maximum at 603 and 629 nm respectively. Graphical Abstract  Two 1D zigzag polymers [(CuS t Bu)4(dppe)] n (1) and [(CuS t Bu)6(bix)] n (2) [dppe = bis(diphenylphosphino) ethane] or bix [bix = 1,4-bis(imidalzole-1-ylmethyl)benzene] have been synthesized by solvothermal reactions using copper(I) tert-butylthiolate CuS t Bu as the starting material. Compounds 1 and 2 contain rare (CuS t Bu)4 and (CuS t Bu)6 clusters as connecting nodes and dppe or bix as bridging ligands. The title compounds show optical transitions with band gaps of ∼3.18 eV for 1 and ∼2.81 eV for 2. Both 1 and 2 exhibit strong photoluminescence with the peak maximums at 603 and 629 nm, respectively. The 1D zigzag polymer of [(CuS t Bu)6(bix)] n (2).  相似文献   

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