Infrared, N.M.R. and mass spectral studies on 3-Amino-4-aryl-5-aryl(or alkyl)imino-4,5-dihydro-1,2,4-thiadiazoles

1975 ◽  
Vol 28 (3) ◽  
pp. 591 ◽  
Author(s):  
CP Joshua ◽  
KN Rajasekharan
Keyword(s):  
Spectral Data ◽  
Structure Elucidation ◽  
Mass Spectra ◽  
Spectral Studies ◽  
Mass Spectral ◽  
Fragmentation Patterns ◽  
Chemical Evidence

Some 3-amino-4-aryl-5-aryl(or alkyl)imino-4,5-dihydro-1,2,4-thiadiazol, previously prepared and assigned structures on chemical evidence, are now confirmed in structure by a detailed study of their spectra. While i.r, and n.m.r, spectral data confirm the nature of the ring present in these compounds, mass spectra confirm the assignment of substituents on the ring. Mass spectra of these compounds exhibit specific fragmentation patterns and consequently are useful in structure elucidation of substituted 4,5-dihydro-1,2,4-thiadiazoles.

Mass Spectra of Some Carbamates and Related Ureas. II

1968 ◽  
Vol 51 (2) ◽  
pp. 347-365 ◽  
Author(s):  
W R Benson ◽  
J N Damico
Keyword(s):  
Spectral Data ◽  
Relative Abundance ◽  
Mass Spectra ◽  
The Other ◽  
Methyl Isocyanate ◽  
Mass Spectral Data ◽  
Mass Spectral ◽  
Fragmentation Patterns ◽  
Sulfur Containing

Abstract Mass spectral data for fourteen carbamates, live dithiocarbamates, one thiocarbamate, and eight phenylureas are given with some interpretations. Among the compounds examined were some sulfur-containing aliphatic oxime carbamates; these lost the sulfur moieties more easily than the methyl isocyanate moiety. In the aryl IV-methylcarbamate series, the CH3NCO moiety appears to be lost most easily, as it is in pyrolysis. When l-(2-chlorophenyI)-3- methylurea is fragmented, unexpectedly the [HNC0]+ ion is found in high relative abundance. However, the remaining ureas undergo fragmentation in a manner similar to their related carbamates. Although the two ethylene bisdithiocarbamates give essentially identical fragmentation patterns, the spectra of the other four thio- and dithiocarbamates show sufficient differences so that they may be distinguished from one another.

Mass Spectral Studies on Pyrazaboles

1976 ◽  
Vol 31 (12) ◽  
pp. 1662-1666 ◽  
Author(s):  
C. E. May ◽  
K. Niedenzu ◽  
S. Trofimenko
Keyword(s):  
Electron Impact ◽  
Mass Spectra ◽  
Ring System ◽  
Hydrogen Halide ◽  
Spectral Studies ◽  
Mass Spectral ◽  
Fragmentation Patterns ◽  
Structural Entity

The mass spectra of several pyrazaboles of type 1 (R = H) have been studied. The data illustrate that electron impact causes three major fragmentation patterns for the species. Symmetrical cleavage of the pyrazabole followed by further breakdown is common to all compounds. In addition, those pyrazaboles containing H or CH3 at the C atoms of the pyrazole rings undergo an electron impact-induced rearrangement which appears to result in the formation of a species containing a B2N3 ring as a structural entity; subsequent breakdown leads to a B2N2 ring system. The mass spectra of halo- or pseudohalo-substituted pyrazaboles evidence the ready loss of hydrogen halide as a predominant feature; no rearrangement ions are observed.

Mass spectral studies of lanthanide chelates. I. Samarium, europium, gadolinium and terbium chelates of thenoyltrifluoroacetone

1975 ◽  
Vol 28 (7) ◽  
pp. 1513 ◽  
Author(s):  
M Das ◽  
SE Livingstone
Keyword(s):  
Mass Spectra ◽  
The Other ◽  
Spectral Studies ◽  
Mass Spectral ◽  
Lanthanide Chelates ◽  
Other Hand ◽  
Europium Chelates ◽  
Fragmentation Patterns ◽  
Terbium Chelates ◽  
Bivalent State

The mass spectra of the lanthanide chelates of thenoyltrifluoroacetone, viz. Met{CF3COCH=C(O-)-C4H3S}3 (Met = Sm, Eu, Gd, Tb), have been obtained. All four spectra display similar fragmentation patterns. Fluorine migration to the metal with the concomitant loss of :CF2 occurs with all four lanthanide chelates. Peaks were observed for the ions [MetF2]+ (Met = Sm, Gd, Tb) and [MetF]+ (Met = Sm, Eu). The occurrence of [MetF]+ in the spectra of the samarium and europium chelates is in keeping with the tendency of these two lanthanides to be reduced to the bivalent state. On the other hand, oxidation of terbium(III) to terbium(IV) was not observed in the mass spectra.

Mass Spectra of β-Keto Esters

1972 ◽  
Vol 50 (16) ◽  
pp. 2707-2710 ◽  
Author(s):  
Larry Weiler
Keyword(s):  
Mass Spectra ◽  
Carbonyl Groups ◽  
Mass Spectral Fragmentation ◽  
Mass Spectral ◽  
Keto Esters ◽  
Fragmentation Patterns

The mass spectra of several γ-substituted β-keto esters have been recorded and interpreted. The fragmentation patterns are compared to those of α-substituted β-keto esters and are found to be very useful in differentiating the α- and γ-substituted isomers. The mass spectral fragmentation schemes are dominated by cleavages α to the carbonyl groups and by McLafferty rearrangements.

scholarly journals Synthesis and Bio-Spectral Studies of Co(II) Complex of 5-Chloro-2,4-Dihydroxy Butyrophenoneoxime (CDHBOX)

2010 ◽  
Vol 6 (3) ◽  
pp. 1120-1133
Author(s):  
F. Rehman ◽  
M. Bhardwaj ◽  
U.K. Jetley
Keyword(s):  
Spectral Data ◽  
Standard Free Energy ◽  
Spectral Studies ◽  
Curvularia Lunata ◽  
Mass Spectral ◽  
Ir Studies ◽  
Free Energy Of Formation ◽  
Escherchia Coli ◽  
Elemental Analyses ◽  
Point Determination

Co(II) complex of 5-chloro-2,4-dihydroxy butyrophenoneoxime (CDHBOX) was synthesized from 5-chloro-2,4-dihydroxy butyrophenoneoxime by using standard protocol, and characterized by elemental analyses, melting point determination and spectral data. The ML2 (metal/ligand) stoichiometry of the complex was determined by spectrophotometric and potentiometric studies, and mass spectral data. The value of stability constant of the complex was found to be 6.94x 108 while its standard free energy of formation is 12.155 kcal/mol at 27ºC. Beer’s law is obeyed in the concentration range 2-15 ppm of Co. The value of molar extinction coefficient and sensitivity as per Sandell’s scale were found to 3.35x 103 L.mol-1cm-1and 0.017 μg Co/cm2 respectively. The value of activation energy and the Arrhenius constant Arrhenius constant were found as 4.949 kjmol-1, 74.39. The IR studies reveal that the phenolic proton is lost on complexation and the oxygen of the phenolic (–OH) and nitrogen of the oximino (=NOH) groups coordinate with Co(II) ion. The electronic spectra and magnetic susceptibility measurement indicate that the complex is paramagnetic and tetrahedral in nature. The antimicrobial activity of different concentrations of ligand and its Co(II)-complex  has been evaluated against Curvularia lunata, Fusarium oxysporum and Alternaria alternata fungi  and Streproproteus, Staph, Escherchia coli, Klebsella, and pseudomonas bacteria. The results indicated that the ligand (CDHBOX) and its Co(II) complex have good anti-microbial properties. 

Synthesis of phenethanolamine derivatives with potential β-adrenergic antagonistic activity

1975 ◽  
Vol 28 (5) ◽  
pp. 1023 ◽  
Author(s):  
SJ Pasaribu ◽  
LR Williams
Keyword(s):  
Magnetic Resonance ◽  
Ring Opening ◽  
Proton Magnetic Resonance ◽  
Mass Spectra ◽  
Antagonistic Activity ◽  
Spectral Studies ◽  
Aryl Ring ◽  
Mass Spectral

The mass spectra of bromonitroacetophenones, intermediates in the synthesis of phenethanolamine derivatives containing a nitro and bromo group in the aryl ring, have been studied. The acetophenones were converted into the corresponding α,β-epoxystyrenes, which were then treated with various amines, and proton magnetic resonance and mass spectral studies were used to confirm the direction of ring opening and purity of the products.

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