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1.
A new dioxime ligand, (2E,3E)-3-[(6-{[(1E,2E)-2-(hydroxyimino)-1-methylpropylidene]amino}-pyridin-2-yl)imino]butan-2-one oxime, (H2Pymdo) (3) has been synthesized in H2O by reacting 2,3-butenedione monoxime (2) with 2,6-diaminopyridine. Mono-, di- and tri-nuclear copper(II) complexes of the dioxime ligand (H2Pymdo) and/or 1,10-phenanthroline have been prepared. The dioxime ligand (H2Pymdo) and its copper(II) complexes were characterized by 1H-n.m.r., 13C-n.m.r. and elemental analyses, magnetic moments, i.r. and mass spectral studies. The mononuclear copper(II) complex of H2Pymdo was found to have a 1:1 metal:ligand ratio. Elemental analyses, stoichiometric and spectroscopic data of the metal complexes indicated that the metal ions are coordinated to the oxime and imine nitrogen atoms (C=N). In the dinuclear complexes, in which the first Cu(II) ion was complexed with nitrogen atoms of the oxime and imine groups, the second Cu(II) ion is ligated with dianionic oxygen atoms of the oxime groups and are linked to the 1,10-phenanthroline nitrogen atoms. The trinuclear copper(II) complex (6) was formed by coordination of the third Cu(II) ion with dianionic oxygen atoms of each of two molecules of the mononuclear copper(II) complexes. The data support the proposed structure of H2Pymdo and its Cu(II) complexes.  相似文献   

2.
A new ligand incorporating a dioxime moiety, (2E,3E)-3-[(2-{[(1E,2E)-2-(hydroxyimino)-1-methylpropylidene]amino}phenyl)imino]butan-2-one oxime, (H2Phmdo) (3) has been prepared by reacting 2,3-butanedionemono-{O-[4-(1-methyl-2-oxo-propylideneaminooxy)-2,3-bis-(1-methyl-2-oxo-propylideneaminooxy-methyl)-but-2-enyl]-oxime} (2) with 1,2-phenylenediamine. Mono-, di- and trinuclear copper(II) and/or nickel(II) complexes of H2Phmdo were characterized by elemental analyses, magnetic moments, 1H-n.m.r. and 13C-n.m.r., i.r. and mass spectral studies. The mononuclear copper(II) and nickel(II) complexes of H2Phmdo were found to have a 1:1 metal:ligand ratio. Elemental analyses, stoichiometric and spectroscopic data of the metal complexes indicated that the metal ions are coordinated to the oxime and imine nitrogen atoms (C=N). In the dinuclear complexes, in which the first Cu(II) or Ni(II) ion was complexed with nitrogen atoms of the oxime and imine groups, the second Cu(II) ion is ligated with dianionic oxygen atoms of the oxime groups and are linked to the 1,10-phenanthroline nitrogen atoms. The data support the proposed structure of H2Phmdo and its complexes.  相似文献   

3.
EI induced mass spectral fragmentations of twelve new hydrazones of 2-(3- and 4-)-pyridinecarboxaldehydes and hydrazides of (E)-stilbenyloxyacetic acid as well as N-(E)-stilbenyloxyalkylcarbonyl substituted amino acids were investigated. Fragmentations pathways are proposed on the basis of accurate mass and B/E linked scan spectra measurements. The correlation between the intensities of M+. and the selected fragment ions of these compounds is discussed. The data obtained create the basis for distinguishing isomers.  相似文献   

4.
Electron impact mass spectra of 2-(2-pyridyl)methylene-1,3-dicarbonyl compounds and related heteroaryl species have been investigated. In 3-(2-pyridyl)methylene-2,4-pentanedione, its 6′-methyl and 6′-methoxycarbonyl derivatives and in E- and Z-ethyl 3-oxo-2-(2-pyridyl)methylenebutanoates the base peak arises from the loss of methyl radical from the molecular ion to produce a 3-oxo-3H-indolizinium ion. A marked difference is observed in the behaviour of the geometric isomers of the keto esters. The diketones and E-keto ester carrying a 2-pyridyl substituent and ketone functionality on the same side of the carbon-carbon double bond exhibit an unusually high [M + 1]+/[M] ratio (about 2.5) under normal ionization conditions (pressure 10–100 μPa). This abnormality is a function of pressure only and independent of temperature. In the case of the Z-keto ester, the corresponding malonate, 3- and 4-(2-pyridyl)methylene-2,4-pentanediones, and 2-furyl, 2-thienyl and phenyl diketone analogues, the ratio does not differ much from that due to the natural isotope abundance. Results for 1,1,1,5,5,5-hexadeuterio-2-(2-pyridyl)-methylene-2,4-pentanedione (strong M + 2 peak) suggest one mass unit transfer as an intermolecular proton shift from a methyl group to give a 3-hydroxy-3-methyl-3H-indolizinium ion. This real mass spectrometric phenomenon is a unique example of low pressure self-chemical ionization.  相似文献   

5.
Stereospecific adduct ion formation has been observed in the chemical ionization mass spectra (positive and negative) of certain E- and Z-1,2,3-triaryl-2-propen-1-ones. The Z isomers are found to give higher relative abundances of adduct ions than the E isomers. This has been interpreted in terms of the differences in the proton affinities of the isomers originating from their different degrees of enone resonance. Halide ion (CI? and Br?) attachment spectra of these compounds also show stereochemical differences in the relative abundances of [M]?˙ and [M+halide]? ions, though the effect is not as pronounced as in the case of the positive ion spectra.  相似文献   

6.
The mass spectra of 1-(2′-hydroxy-5′-alkylphenyl)-1-ethanone (E)-oximes 1–6 and 1-(2′-hydroxy-5′-methylphenyl)-1-alkanone (E)-oximes 7–12 are given and the major fragmentation pathways discussed. The simultaneous loss of water and alkyl moieties from the molecular ion indicates that a skeletal rearrangement take place and a cycloheptatrienyloheterocyclic system is formed. The McLafferty rearrangement, γ-fission in the side aliphatic chain and oxygen expulsion are discussed with evidence being drawn from accurate mass measurements, metastable ions and comparison with mass spectral data of related compounds.  相似文献   

7.
The densities and the ultrasonic speeds of the aqueous solutions of 2-(2-hexyloxyethoxy)ethanol (C6E2) were measured over the entire range of mole fractions at 5°C. Excess molar volumes V E were readily calculated from the densities. The densities, in combination with the ultrasonic speeds, furnish estimates of the molar (and excess molar) isentropic compressibilities K S and the deviations u D of the ultrasonic speeds from the values calculated for ideal mixtures. Radical changes in the mole fraction derivatives of the excess molar properties of the (C6E2 + water) system, in the vicinity of an amphiphile mole fraction of 0.003, indicate that C6E2 like C6E3 is capable of micelle formation. Our data have been compared with those reported earlier for (C4E2 +, C2E2 +, and C6E3 + water). We have employed both mass action and pseudophase approaches to data analysis, together with the four-segment model approach.  相似文献   

8.
A new kind of copper(II) complex, CuL(MeOH) (H2L?=?(E)-N 1-(2-((2-aminocyclohexydiimino)(phenyl)methyl)-4-chlorophenyl)-N 2-(2-benzyl-4-chlorophenyl)oxalamide) has been synthesized and its structure determined by single-crystal X-ray methods. Copper(II) ion is five-coordinate, bonding to four nitrogen atoms from H2L and one oxygen atom from MeOH. Hydrogen bonds in the crystal result in the formation of a one-dimensional structure. EPR spectra are discussed. Computer simulation gave g||?=?2.200, g?=?2.002. On the basis of the synthesis and the crystal structure, the mechanism of the metal template reaction involved in the formation of the complex was verified.  相似文献   

9.
The mass spectral fragmentation patterns of ten 7-(o- and p-R-benzylidene)-3-(o- and p-R-phenyl)-3,3a,4,5,6,7-hexahydro-2H-indazoles, I, obtained by electron impact have been studied. All the spectra analyzed contain molecular ions and the principal fragmentation routes take place either from the molecular ion, or from (M+-1) ion. Likewise, our investigation of the mass spectra of these compounds revealed interesting relationships between the substitution pattern in the framework of I and the fragmenation pathways.  相似文献   

10.
The mass spectrometric behaviour of 1-aryl-5-(2-dialkylaminovinyI)-lH-tetrazoles was studied, especially 1-phenyl-5-(2-dimethylaminovinyl)-l H-tetrazole as a typical example of D- and 15N-labelled derivatives revealed a rearrangement via a carbodiimide-like intermediate ion.  相似文献   

11.
Incident ion energy E1 and collision gas pressure have been adjusted so as to obtain a satisfactory tandem mass spectrum of the m/z 1882 ion formed from valme-gramicidin A (relative molecular mass 1881). Translational energy losses ΔE have been determined (at Ei = 14.8 keV) from the precise positions of a large number of fragment ion peaks in the spectrum. The variation in ΔE for different fragment ions is great and the magnitudes of ΔE are large (being commonly of the order of 102 eV). It is shown how very large energy losses ΔE can arise, if the parent ion decomposes to a small fragment ion which itself collides and decomposes further. Implications of the dependence of ΔE upon fragment ion mass for the scan laws of four-sector instruments are discussed briefly.  相似文献   

12.
This article describes the synthesis of a new (2E,3E,6R,9E,11E)-6-isopropenyl-3,6,10-trimethyl-5,8-dioxa-4,9-diazadodeca-3,9-diene-2,11-dione dioxime (H2hmdm), and its mono-, homo, and heterodinuclear copper(II)/nickel(II) complexes. Elemental analyses, stoichiometric and spectroscopic data of the metal complexes indicated that the metal ions are coordinated to the oxime and imine nitrogen atoms (C=N). The Cu(H2hmdm), molecule coordinates to the second copper(II) ion through the oximate oxygens to afford a binuclear structure doubly bridged by the oximate groups in the cis arrangement. In the dinuclear complexes, in which the first CuII ion was complexed with nitrogen atoms of the oxime and imine groups, the second CuII ion is ligated with the 1,10-phenanthroline nitrogen atoms. Ligand and its mononuclear copper(II), homo and heterodinuclear copper(II)–nickel(II) complexes of (H2hmdm) were characterized by elemental analyses, magnetic moments, 1H-n.m.r. and 13C-n.m.r., i.r., and mass spectral studies. The data support the proposed structure of H2hmdm and its complexes.  相似文献   

13.
A cycloreversal reaction, leading to aroyl cations, is the major process in 2-aryl-4H-3,1-benzoxazin-4-ones under electron impact conditions. The ortho interaction of the methoxy and the nitro groups in the 2-phenyl moieties in these compounds present the most abundant ions at m/z 119 and 134, respectively, in their mass spectra as a result of the transfer of a hydrogen atom from the former and an oxygen atom from the latter to the imine nitrogen of the heterocycle. The ion structures and the mechanisms for the proposed fragmentations are based on high-resolution data, B/E and B2/E linked-scan spectra, collision-activated decomposition–B-/E linked-scan spectra and deuterium labelling.  相似文献   

14.
在乙酸酐中用2,9-二甲基-1,10-菲咯啉与水杨醛缩合反应得到2,2′-(1E,1′E)-2,2′-(1,10-菲咯啉-2,9-二基)双(乙烯-2,1-二基)双(2,1-亚苯基)二乙酸酯(探针1);再将其进一步水解得到2,2′-(1E,1′E)-2,2′-(1,10-菲咯啉-2,9-二基)双(乙烯-2,1-二基)二苯酚(探针2)。经1H NMR、13C NMR、IR、MS表征,探针化合物为大共轭结构,发光性能良好。两种探针分别表现出对Cu2+、Ag+不同的荧光猝灭作用,探针2还能识别阴离子F-和AcO-,具有双功能离子检测性能。光谱滴定、等温滴定量热及质谱等测定了配合物组成、作用常数及热力学参数,探针与金属离子的配合为放热反应,作用比为2∶1。  相似文献   

15.
在乙酸酐中用2,9-二甲基-1,10-菲咯啉与水杨醛缩合反应得到2,2’-(1E,1’E)-2,2’-(1,10-菲咯啉-2,9-二基)双(乙烯-2,1-二基)双(2,1-亚苯基)二乙酸酯(探针1);再将其进一步水解得到2,2’-(1E,1’E)-2,2’-(1,10-菲咯啉-2,9-二基)双(乙烯-2,1-二基)二苯酚(探针2)。经1H NMR、13C NMR、IR、MS表征,探针化合物为大共轭结构,发光性能良好。两种探针分别表现出对Cu2+、Ag+不同的荧光猝灭作用,探针2还能识别阴离子F-和AcO-,具有双功能离子检测性能。光谱滴定、等温滴定量热及质谱等测定了配合物组成、作用常数及热力学参数,探针与金属离子的配合为放热反应,作用比为2:1。  相似文献   

16.
Summary Useful ion yields Y of secondary ion mass spectrometry (SIMS) analyses were measured for GaAs bombarded with O 2 + primary ions at normal incidence. The useful ion yields of several analytes were found to decrease with increasing ionisation potentialE i of the analytes far less drastically than reported in the literature. For valuesE i lower than 8 eV only a slight decrease of Y with increasing ionisation potential is observed. The saturation of the useful ion yields at lower values of the ionisation potential is interpreted to result from very high ion fractions. If an ion fraction of unity is assumed for Ga the ion fractions of impurities withE i lower than 8 eV would exceed 40%. For analytes withE i higher than 8 eV the ion fraction decreases rapidly with increasing ionisation potential. A value of 8×10–4 is estimated for the matrix element As (E i= 9.81 eV).
Ionenausbeuten von Matrixelementen und Dotierstoffen in GaAs unter O 2 + -Primärionenbeschuß
  相似文献   

17.
The three mono substituted N-[(E)-3-(4-hydroxyphenyl)prop-2-enoyl]spermidines 1–3 have been studied by positive-ion electrospray-ionization tandem mass spectrometry (ESI-MS/MS). Because of the neighboring-group participation, the MS/MS of [ 1 + H]+ and [ 2 + H]+ are essentially similar, while compound 3 can be easily distinguished from 1 and 2 because of the characteristic ions at m/z 218. However, with the source collision-induced dissociation (source-CID) MS/MS technique, the compounds 1 and 2 can be unambiguously distinguished by the signal of the pyrrolidinium ion (m/z 72) from their daughter ion (m/z 275). The source-CID MS/MS of the labeled compound N-(4-aminobutyl)-N-(3-aminopropyl)-N-[3-(4- hydroxyphenyl)prop-2-en[15N]amide] ([15N(4)]- 2 ) provide more information on the decomposition mechanisms and proved the occurrence of a partial transamidation reaction 2→1 during the measurement.  相似文献   

18.
Abstract

A facile procedure is presented for the synthesis of (E)-1-(3′-hydroxy-2′-furanyl)-3-(3″-hydroxy-4″-methoxyphenyl)-2- propen-1-one (6). Galactosylisomaltol (1) was condensed with isovanillin (2) under strong alkaline conditions at 25 [ddot]C to form (E)-1-(3′-O-β-D-galactopyranosyloxy-2′-furanyl)-3-(3″- hydroxy-4″-methoxyphenyl)-2-propen-1-one (4). (E)-1-(3′-hydroxy-2′-furanyl)-3-(3″-hydroxy-4″-methoxyphenyl)-2-propen-1-one (6) was obtained by acid hydrolysis of 4 in a 53.9% yield. This hetero-cyclic 2-propen-1-one was characterized on the basis of spectral data (IR and 1H NMR), physicochemical properties, and conversion to a mono-O-acetyl derivative.  相似文献   

19.
By unambiguous methods, (Z)- and (E)-2, 3-dimethyl(1, 1, 1, 4, 4, 4-2H6)but-2-enes ( 3 ) were synthesized and transformed to the epoxides 4 with 3-chloroperbenzoic acids. Both the isotopomeric olefins and the epoxides are detected separately by 1H-NMR at 400 MHz. Epoxidation of (Z)- 3 with [RhICl(PPh3)3]/cumene hydroperoxide resulted in a 1: 1 mixture of (Z)- and (E)- 4 , while reaction of (Z)- 3 with [FeIII(tpp)]Cl/PhIO gave only (Z)- 4 (tpp = tetraphenylporphyrin).  相似文献   

20.
Eighteen compounds unknown in the literature, N-(E)-stilbenyloxyalkylcarbonyl- and N-(E)-stilbenyloxyalkylcarbonylaminoalkylcarbonyl-substituted hydrazones of 2-, 3- and 4-pyridinecarboxaldehydes have been prepared. The stereochemical behavior of these compounds in dimethyl-d6 sulfoxide solution has been studied by 1H-nmr technique. The E geometrical isomers and cisltrans amide conformers have been found for N-substituted-hydrazones 1–16 .  相似文献   

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