AN ATTEMPT TO STUDY COMPLEX FORMATION BETWEEN 1,3,5-TRINITROBENZENE AND OLEFINS BY GAS CHROMATOGRAPHY

1964 ◽  
Vol 42 (11) ◽  
pp. 2410-2416 ◽  
Author(s):  
R. J. Cvetanovié ◽  
F. J. Duncan ◽  
W. E. Falconer
Keyword(s):  
Molecular Weight ◽  
Gas Chromatography ◽  
Double Bond ◽  
Complex Formation ◽  
Carbon Number ◽  
Molecular Iodine ◽  
Structural Features ◽  
Steric Effects ◽  
Chromatographic Technique ◽  
Structural Isomers

An attempt has been made to study complex formation between 1,3,5-trinitrobenzene (TNB) and olefins by a gas chromatographic technique. A particular interpretation of the data indicates that the TNB – olefin complexes exhibit progressive increases in stability with increasing double-bond substitution. Steric effects are less pronounced than for olefin complexes with silver nitrate or molecular iodine. Olefins are well separated by carbon number, and differences in retention times among the structural isomers of each molecular weight are sufficiently characteristic to provide a basis for assigning major structural features.

Quantification of isomerically summed hydrocarbon contributions to crude oil by carbon number, double bond equivalent, and aromaticity using gas chromatography with tunable vacuum ultraviolet ionization

The Analyst ◽  
2018 ◽  
Vol 143 (6) ◽  
pp. 1396-1405 ◽  
Author(s):  
Jeremy A. Nowak ◽  
Robert J. Weber ◽  
Allen H. Goldstein
Keyword(s):  
Gas Chromatography ◽  
Double Bond ◽  
Crude Oil ◽  
Vacuum Ultraviolet ◽  
Carbon Number

GC × GC with tunable vacuum ultraviolet photoionization distinguishes and isomerically quantifies aliphatic and aromatic fractions of crude oil hydrocarbon classes.

Determination of Water and Ethyl Alcohol in Cosmetics by Gas Chromatography

1966 ◽  
Vol 49 (4) ◽  
pp. 718-720
Author(s):  
Frederick C Gross
Keyword(s):  
Molecular Weight ◽  
Gas Chromatography ◽  
Polyethylene Glycol ◽  
High Molecular Weight ◽  
Ethyl Alcohol ◽  
Internal Standard ◽  
Solid Support ◽  
Chromatographic Technique ◽  
Methyl Cellosolve

Abstract A gas chromatographic technique for determining water and/or ethyl alcohol in cosmetics utilizes a relatively inert perfluorocarbon solid support coated with a high molecular weight polyethylene glycol. Methyl Cellosolve, used as solvent, is suitable for most cosmetic preparations and serves as an internal standard. Although semi-emperical, this procedure yields satisfactory results for the usual amounts of water and/or ethyl alcohol found in cosmetics. The method is recommended for adoption as official, first action.

scholarly journals Correction: Quantification of isomerically summed hydrocarbon contributions to crude oil by carbon number, double bond equivalent, and aromaticity using gas chromatography with tunable vacuum ultraviolet ionization

The Analyst ◽  
2019 ◽  
Vol 144 (12) ◽  
pp. 3898-3898
Author(s):  
Jeremy A. Nowak ◽  
Robert J. Weber ◽  
Allen H. Goldstein
Keyword(s):  
Gas Chromatography ◽  
Double Bond ◽  
Crude Oil ◽  
Vacuum Ultraviolet ◽  
Carbon Number

Correction for ‘Quantification of isomerically summed hydrocarbon contributions to crude oil by carbon number, double bond equivalent, and aromaticity using gas chromatography with tunable vacuum ultraviolet ionization’ by Jeremy A. Nowak et al., Analyst, 2018, 143, 1396–1405.

Configuration on the C=N double bond of monosubstituted amidines and amidoximes

1989 ◽  
Vol 54 (12) ◽  
pp. 3245-3252 ◽  
Author(s):  
Bernard Tinant ◽  
Janine Dupont-Fenfau ◽  
Jean-Paul Declercq ◽  
Jaroslav Podlaha ◽  
Otto Exner
Keyword(s):  
Double Bond ◽  
Nitrogen Atom ◽  
Steric Effects ◽  
Model Compounds ◽  
X Ray ◽  
Analogous Model

Configuration on the C=N double bond of amidines and amidoximes is controlled by steric effects on the second nitrogen atom but there is a difference in the case of N’-monosubstituted derivatives: amidines prefer E configuration (conformation around the C-N bond sp) and amidoximes Z configuration (conformation ap). This was confirmed by the X-ray structures of two analogous model compounds N,N’-dimethyl-4-nitrobenzamidine (monoclinic, P21c, a = 10.855(3), b = 11.043(3), c = 8.593(3) Å, β = 105.69(2)°, V = 991.8(5) Å3, Z = 4, Dx = 1.29 g cm-3, CuKα, λ = 1.5418 Å, μ = 7.91 cm-1, F(000) = 408, T = 291 K, R = 0.065 for 1 265 observed reflections) and N’-methyl-4-nitrobenzamidoxime (monoclinic, P21/a, a = 6.699(2), b = 24.178(9), c = 6.075(2) Å, β = 106.20(3)°, V = 944.9(6) Å3, Z = 4, Dx = 1.37 g cm-3, CuKα, λ = 1.5418 Å, μ =9.22 cm-1, F(000) = 408, T = 291 K, R = 0.079 for 1 278 observed reflections).

The Reactions of Substituted Germyl- and Silylhydrazines with BX3 and CY2 Acceptor Species

1972 ◽  
Vol 50 (4) ◽  
pp. 562-566 ◽  
Author(s):  
L. K. Peterson ◽  
K. I. Thé
Keyword(s):  
Molecular Weight ◽  
Nitrogen Atom ◽  
Low Temperatures ◽  
Adduct Formation ◽  
Steric Effects ◽  
Reaction Products ◽  
Hydrazine Derivatives ◽  
Basic Catalysts ◽  
Series Of Experiments ◽  
Electronic And Steric Effects

Boron trimethyl reacts with each of the organometalloid-hydrazine derivatives Me2NN(R)GeMe3 (R = H, Me, SiMe3) except Me2NN(SiMe3)GeMe3, and with Me2NNHSiMe3, forming 1:1 adducts. With Me2NN(SiMe3)GeMe3 and BMe3, no adduct was formed even at low temperatures. On the basis of p.m.r. spectra, the metalloid-substituted nitrogen atom rather than the terminal nitrogen, is indicated as the basic center at which adduct formation occurs. With BF3, the Si—N and Ge—N bonds of the hydrazine derivatives were cleaved, again indicating attack at the central nitrogen atom. In a series of experiments involving CY2 (Y = O, S) and Me2NN(R)MMe3 (R = H, Me, SiMe3; M = Si, Ge), reaction occurred readily for R = H, but less readily for R = Me and for the compound Me2NN(GeMe3)2, while no reaction was observed for the compounds Me2NN(SiMe3)2 and Me2NN(SiMe3)GeMe3, even when heat or basic catalysts were employed. Reaction products, carbamate and thiocarbamate derivatives, Me2NN(R)C(Y)YMMe3, were characterized on the basis molecular weight, i.r., p.m.r., and mass spectroscopy, and m.p. data. Ease of formation is discussed in terms of electronic and steric effects.

Comparative analysis of complex formation of magnesium and calcium ions with low-molecular-weight and unfractionated heparin

2007 ◽  
Vol 52 (4) ◽  
pp. 645-651 ◽  
Author(s):  
A. N. Semenov ◽  
L. S. Nikolaeva ◽  
M. N. Mamontov ◽  
L. A. Lyapina ◽  
V. E. Pastorova ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Comparative Analysis ◽  
Complex Formation ◽  
Unfractionated Heparin ◽  
Calcium Ions ◽  
Low Molecular Weight
Sign in / Sign up

Export Citation Format

Share Document