scholarly journals A coordinatively flexible hexadentate ligand gives structurally isomeric complexesM2(L)X3(M= Cu, Zn;X= Br, Cl)

2016 ◽  
Vol 72 (1) ◽  
pp. 68-74 ◽  
Author(s):  
Christina Wegeberg ◽  
Vickie McKee ◽  
Christine J. McKenzie
Keyword(s):  
Homogeneous Catalysis ◽  
Metal Binding ◽  
Mass Spectra ◽  
The Other ◽  
Ionization Mass ◽  
Trigonal Bipyramidal ◽  
Carboxylate Bridge ◽  
Square Planar ◽  
Binding Agents ◽  
Hexadentate Ligand

Polypyridyl multidentate ligands based on ethylenediamine backbones are important metal-binding agents with applications in biomimetics and homogeneous catalysis. The seemingly hexadentate tpena ligand [systematic name:N,N,N′-tris(pyridin-2-ylmethyl)ethylenediamine-N′-acetate] reacts with zinc chloride and zinc bromide to form trichlorido[μ-N,N,N′-tris(pyridin-2-ylmethyl)ethylenediamine-N′-acetato]dizinc(II), [Zn2(C22H24N5O2)Cl3], and tribromido[μ-N,N,N′-tris(pyridin-2-ylmethyl)ethylenediamine-N′-acetato]dizinc(II), [Zn2Br3(C22H24N5O2)]. One ZnIIion shows the anticipated N5O coordination in an irregular six-coordinate site and is linked by ananticarboxylate bridge to a tetrahedral ZnX3(X= Cl or Br) unit. In contrast, the CuIIions in aquatribromido[μ-N,N,N′-tris(pyridin-2-ylmethyl)ethylenediamine-N′-acetato]dicopper(II)–tribromido[μ-N,N,N′-tris(pyridin-2-ylmethyl)ethylenediamine-N′-acetato]dicopper(II)–water (1/1/6.5) [Cu2Br3(C22H24N5O2)][Cu2Br3(C22H24N5O2)(H2O)]·6.5H2O, occupy two tpena-chelated sites, one a trigonal bipyramidal N3Cl2site and the other a square-planar N2OCl site. In all three cases, electrospray ionization mass spectra were dominated by a misleading ion assignable to [M(tpena)]+(M= Zn2+and Cu2+).

Zur Chemie der 1,3,5-Triaza-2-phosphorinan-4,6-dione. Teil IX. Umsetzungen einiger 1,3,5-Triorgano-1,3,5-triaza-2λ3-phosphorinan-4,6-dione mit Hexafluoraceton / Chemistry of the 1,3,5-Triaza-2-phosphorinan-4,6-diones. Part IX. Reaction of some 1,3,5-Triorgano-1,3,5-triaza-2λ3-phosphorinan-4,6-diones with Hexafluoroacetone

1995 ◽  
Vol 50 (12) ◽  
pp. 1785-1790 ◽  
Author(s):  
Ion Neda ◽  
Michael Farkens ◽  
Axel K. Fischer ◽  
Peter G. Jones ◽  
Reinhard Schmutzler
Keyword(s):  
Crystal Structure ◽  
Phosphorus Atom ◽  
Mass Spectra ◽  
Membered Ring ◽  
The Other ◽  
X Ray ◽  
Trigonal Bipyramidal ◽  
Phosphoryl Compound ◽  
Spirocyclic Compounds

The reactions of 2-(2-chloroethyl)amino-1,5-dimethyl-3-phenyl-1,3,5-triaza-2λ3-phosphorinan- 4,6-dione (1), 2-bis(2-chloroethyl)amino-1,5-dimethyl-3-phenyl-1,3,5-triaza-2A3-phosphorinan- 4,6-dione (2), 2-methoxy-1,3,5-trimethyl-1,3,5-triaza-2λ3-phosphorinan-4,6-dione (3) and 2-trimethylsiloxy-1,3,5-trimethyl-1,3,5-triaza-2λ3-phosphorinan-4,6-dione (5) with hexafluoracetone are described. In the case of 2 and 3 the reaction furnished the spirocyclic compounds 7 and 8. 2-Bis(2-chloroethyl)amino-1,3,5-triphenyl-1,3,5-triaza-2λ3-phosphorinan- 4,6-dione (4) did not react. In the case of 1 and 5 rearrangement reactions took place; the (2-chloroethyl)amino substituent of 1 reacted with one of two equivalents of hexafluoroacetone with formation of the spirocyclic phosphorane 6. The reaction of 5 with tetrabromoorthobenzoquinone gave the phosphoryl compound 9. Compounds 6 - 8 were characterized via their 1H-, 13C-, 19F- and 31P-NMR and mass spectra, compound 9 via its 1H-, 13C- and 31P-NMR and mass spectra. An X-ray crystal structure determination of 8 was conducted; in the six-membered ring the phosphorus atom lies 73 pm out of the plane of the other atoms, and displays trigonal bipyramidal coordination.

A FACILE SYNTHESIS AND REACTIONS OF AMINO SELENOLO[2,3-b]PYRIDINE CARBOXYLATE

2015 ◽  
Vol 12 (1) ◽  
pp. 3910-3918 ◽  
Author(s):  
Dr Remon M Zaki ◽  
Prof Adel M. Kamal El-Dean ◽  
Dr Nermin A Marzouk ◽  
Prof Jehan A Micky ◽  
Mrs Rasha H Ahmed
Keyword(s):  
Biological Activity ◽  
Carbonyl Compounds ◽  
Mass Spectra ◽  
The Other ◽  
Pyridine Derivatives ◽  
Facile Synthesis ◽  
High Biological Activity ◽  
Basic Hydrolysis ◽  
Pyridine Carboxylate ◽  
Hydrolysis Of

 Incorporating selenium metal bonded to the pyridine nucleus was achieved by the reaction of selenium metal with 2-chloropyridine carbonitrile 1 in the presence of sodium borohydride as reducing agent. The resulting non isolated selanyl sodium salt was subjected to react with various α-halogenated carbonyl compounds to afford the selenyl pyridine derivatives 3a-f  which compounds 3a-d underwent Thorpe-Ziegler cyclization to give 1-amino-2-substitutedselenolo[2,3-b]pyridine compounds 4a-d, while the other compounds 3e,f failed to be cyclized. Basic hydrolysis of amino selenolo[2,3-b]pyridine carboxylate 4a followed by decarboxylation furnished the corresponding amino selenolopyridine compound 6 which was used as a versatile precursor for synthesis of other heterocyclic compound 7-16. All the newly synthesized compounds were established by elemental and spectral analysis (IR, 1H NMR) in addition to mass spectra for some of them hoping these compounds afforded high biological activity.

scholarly journals Discrimination of structural isomers of amphetamine using carbon dioxide negative-ion chemical ionization mass spectrometry

1997 ◽  
Vol 13 (2) ◽  
pp. 151-161 ◽  
Author(s):  
Kevin B. Thurbide ◽  
C. M. Elson ◽  
P. G. Sim
Keyword(s):  
Carbon Dioxide ◽  
Mass Spectra ◽  
Chemical Ionization ◽  
Negative Ion ◽  
Ionization Mass ◽  
Structural Isomers ◽  
Mass Spectral ◽  
Negative Ion Chemical Ionization ◽  
Spectral Behaviour ◽  
Carbon Dioxide Plasma

The negative‒ion chemical ionization mass spectra of a group of structural isomers of amphetamine have been studied using carbon dioxide as the reagent gas. Characteristic and reproducible differences are observed for each member of the set implying that this technique offers a means of distinguishing among groups of amphetamine isomers. Characteristic adducts to the molecular ion are observed in the form (M–[H]+[O]) and (M–[H]+[CO2]). Descriptions of some fragments are given based on the mass spectral behaviour of a set of analogue compounds and the results of oxygen-18 labelled carbon dioxide reagent gas experiments. Contents of the carbon dioxide plasma and their impact on various analytes is also discussed.

scholarly journals MASS SPECTRA OF SOME FUROQUINOLINE ALKALOIDS

1965 ◽  
Vol 43 (9) ◽  
pp. 2516-2521 ◽  
Author(s):  
D. M. Clugston ◽  
D. B. Maclean
Keyword(s):  
Electron Impact ◽  
Mass Spectra ◽  
The Other ◽  
Methoxyl Group ◽  
Quinoline Ring

The mass spectra of six furoquinoline alkaloids have been recorded and mechanisms have been proposed for their fragmentation upon electron impact. Strong metastable peaks, present in all spectra, have aided in the interpretation of the fragmentation of these alkaloids. The three alkaloids with a methoxyl group in the 8-position of the quinoline ring may be differentiated from the other three by the presence of relatively intense peaks at M-1 and M-29.

The monomeric metaphosphate anion in negative-ion chemical-ionization mass spectra of phosphotriesters

1984 ◽  
Vol 106 (23) ◽  
pp. 6877-6883 ◽  
Author(s):  
Seymour Meyerson ◽  
Donald J. Harvan ◽  
J. Ronald Hass ◽  
Fausto Ramirez ◽  
James F. Marecek
Keyword(s):  
Mass Spectra ◽  
Chemical Ionization ◽  
Negative Ion ◽  
Ionization Mass ◽  
Negative Ion Chemical Ionization
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