THE MASS SPECTRA OF THREE DEUTERATED BUTANOLS

1958 ◽  
Vol 36 (6) ◽  
pp. 990-998 ◽  
Author(s):  
W. H. McFadden ◽  
M. Lounsbury ◽  
A. L. Wahrhaftig
Keyword(s):  
Hydrogen Atom ◽  
Mass Spectra ◽  
Excess Energy ◽  
Strong Tendency ◽  
Hydroxyl Group ◽  
Charge Localization

The mass spectra of 1,1-dideutero-l-butanol, 1,1,1,3,3-pentadeutero-2-butanol, and 1,1,1,2,3,3-hexadeutero-2-butanol have been obtained using 70-volt ionizing electrons. Comparison of the cracking patterns of the deuterated butanols with those of the undeuterated compounds confirms certain known features of the mass spectra of alcohols and reveals further information regarding the formation of several rearrangement ions. The strong tendency for alcohols to break at bonds beta to the hydroxyl group has been attributed to charge localization on the oxygen and this feature is used to explain the formation of many of the rearrangement ions. It is postulated that a hydrogen atom may be transferred to the electron-deficient oxygen and that the resulting structure distributes its excess energy and charge to give the activated complexes leading to the observed ions.

Inductive effect in EI-mass spectra of some 5,6-dihalogenides and 5,6-halohydrins of 5α-cholestan-3β-ol and 3β-acetoxy-5α-cholestane

1982 ◽  
Vol 47 (11) ◽  
pp. 2946-2960 ◽  
Author(s):  
Antonín Trka ◽  
Alexander Kasal
Keyword(s):  
Mass Spectra ◽  
Inductive Effect ◽  
Molecular Ions ◽  
Hydroxyl Group ◽  
Halogen Atoms ◽  
Derivatives Of

Partial EI-mass spectra of 3β-hydroxy- and 3β-acetoxy-5α-cholestanes substituted in positions 5α-, 6β- or 5α,6β- with a hydroxyl group or halogen atoms (fluorine, chlorine, bromine) are presented. The molecular ions of 5α,6β-disubstituted derivatives of 3β-hydroxy-5α-cholestane (or of its 3-acetate) are considerably more stable than the corresponding monosubstituted derivatives if at least one of the pair of the vicinal substituents is chlorine or fluorine. This increase in stability, most striking in 5α- and 6β-fluoro compounds, is explained by the inductive effect.

scholarly journals Complexation of Cu(BF4)2 with 3-hydroxyflavone in acetonitrile: quantum chemical calculation

2018 ◽  
Keyword(s):  
Hydrogen Bond ◽  
Hydrogen Atom ◽  
Intramolecular Hydrogen Bond ◽  
Quantum Chemical ◽  
Phenyl Ring ◽  
Fluorine Atom ◽  
Quantum Chemical Study ◽  
Hydroxyl Group ◽  
Chemical Calculation ◽  
Intramolecular Hydrogen

In the article the results of the quantum chemical study of copper (II) solvato-complexes with acetonitrile (AN), tetrafluoroborate anion (BF4–) and 3-hydroxyflavone (flv) of the composition [Cu(AN)6]2+, [Cu(BF4)(AN)5]+, [Cu(flv)(AN)5]2+, [Cu(flv)(BF4)(AN)4]+ are presented. Calculations were done using density function theory (DFT) on the M06-2X/6-311++G(d,p) level of theory. Obtained results were interpreted in terms of complexes geometry and topology of electron density distribution using non-covalent interactions (NCI) approach. It was shown that flv molecule is a monodentate ligand in copper (II) complexes and coordinates central atom via carbonyl oxygen. Intramolecular hydrogen bond that exists in an isolated flv molecule was found to be broken upon [Cu(flv)(AN)5]2+ complex formation. In [Cu(flv)(AN)5]2+ complex, a significant rotation of phenyl ring over the planar chromone fragment was spotted as a consequence of intramolecular hydrogen bond breaking. Upon inclusion of BF4– anion to the first solvation shell of Cu2+, an intracomplex hydrogen bond was formed between hydrogen atom of hydroxyl group of flv molecule and the closest fluorine atom of BF4– anion. NCI analysis had shown that a hydrogen bond between hydrogen atom of hydroxyl group of flv molecule and the closest fluorine atom of BF4– anion is significantly stronger than intramolecular hydrogen bond in an isolated flv molecule. In addition, flexible phenyl ring of flv molecule in [Cu(flv)(BF4)(AN)4]+ complex was found to be internally stabilized by the weak van der Waals attraction between oxygen atoms of chromone ring and phenyl hydrogens. These evidences led to a conclusion that [Cu(flv)(BF4)(AN)4]+ complex is more stable, comparing to the in [Cu(flv)(AN)5]2+ complex.

Mass Spectrometry of N-Benzoyl-2-hydroxyalkylamines. Role of the Hydroxylic Hydrogen in the Fragmentation Pattern

1975 ◽  
Vol 53 (21) ◽  
pp. 3175-3187 ◽  
Author(s):  
Don C. DeJongh ◽  
Denis C. K. Lin ◽  
Pierre LeClair-Lanteigne ◽  
Denis Gravel
Keyword(s):  
Mass Spectrometry ◽  
Mass Spectra ◽  
Hydroxyl Group ◽  
Fragmentation Pattern ◽  
Relative Importance ◽  
Hydrogen Atoms ◽  
Related Compounds ◽  
Double Hydrogen ◽  
Hydrogen Rearrangement

An interesting rearrangement has been observed in the mass spectra of a series of N-benzoyl-2-hydroxyalkylamines. The hydrogen atom of the hydroxyl group is transferred to the N-benzoyl portion of the molecular ion and the bond between positions 1 and 2 in the N-alkyl group is cleaved. A rearrangement ion, observed at m/e 135, is formed along with a neutral aldehyde or ketone. When the hydroxylic hydrogen is replaced by a trimethylsilyl substituent, the latter group is transferred with comparable efficiency. Differences in the relative importance of this rearrangement in the mass spectra of a series of related compounds with decreasing substitution at position 2, have been explained by differences in the stabilities of the neutral molecules formed along with m/e 135 and by the occurrence of a double hydrogen rearrangement which competes if hydrogen atoms are present in a relationship gamma and delta to the carbonyl group.

Structure of Cerebrosides. II. Small Angle X-Ray Diffraction Study of Cerasine

1979 ◽  
Vol 34 (12) ◽  
pp. 1121-1124 ◽  
Author(s):  
R. Hosemann ◽  
J. Loboda-Čačković ◽  
H. Čačković ◽  
S. Fernandez-Bermúdez ◽  
F. J. Baltá-Calleja
Keyword(s):  
Molecular Weight ◽  
Fatty Acid ◽  
Hydrogen Atom ◽  
Low Temperature ◽  
Hydroxyl Group ◽  
X Ray Diffraction ◽  
Orientational Disorder ◽  
X Ray ◽  
Long Period ◽  
Lattice Planes

Cerasine having a molecular weight of 800 differs chemically from phrenosine only in the hydroxyl group attached to the fatty acid tail which is replaced by a hydrogen atom. Nevertheless, remarkable differences between both cerebrosides are detected in the lamellae periodicities. In the range of 23 - 66 °C just one single (instead of two) structure with a similar subcell to the triclinic one component of phrenosine is detected. Between 66 and 87 °C three new components (instead of one in phrenosine) appear. Two of the structures are similar to the two phrenosine-components at low temperature and the tilt angles of their chains with respect to the basal planes can explain the stabilizing capacity of the 201 and 301 netplanes of the paraffin-like subcells respectively. These lattice planes are parallely aligned to the surfaces of the lamellae. The long period of 58 Å of component II cannot be explained in such a wav. This period persits upto 105 °C and coexists from 87 °C with a new component showing a 40 Å-periodicity, which cannot either be explained in the above manner. Paracrystalline distortions of the arrangement of the bilayers can be justified by orientational disorder of the galactose heads.

scholarly journals Chemical and biochemical studies on 18-hydroxyoestrone

1974 ◽  
Vol 137 (2) ◽  
pp. 263-272 ◽  
Author(s):  
John K. Findlay ◽  
Lothar Siekmann ◽  
Heinz Breuer
Keyword(s):  
Mass Spectra ◽  
Strong Acid ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
No Formation ◽  
Polar Metabolites ◽  
Characteristic Fragmentation ◽  
Liquid Chromatographic

1. 18-Hydroxyoestrone was reduced by NaBH4 in methanol, giving 18-hydroxyoestradiol-17α and 18-hydroxyoestradiol-17β in the ratio 3:7. 2. Treatment of 18-hydroxyoestrone with a strong alkali yielded 18-noroestrone; however, the 18-hydroxyoestradiols did not undergo transformation to their respective 18-nor derivatives. 3. All the 18-hydroxylated oestrogens were stable under acid conditions. They formed Kober chromogens: the chromogenicity of 18-hydroxyoestrone was only one-third that of the 18-hydroxyoestradiols and oestriol. 4. Paper-, thin-layer- and gas–liquid-chromatographic systems for the characterization of these compounds are described. 5. An examination of the mass spectra revealed peaks characteristic of the substituted carbon atoms. Definite assignment of the 17α- and 17β-hydroxyl groups of the epimeric 18-hydroxyoestrogens was possible by characteristic fragmentation of the free steroids. Further, the configuration of 18-hydroxyoestradiol-17β was confirmed by the formation of the dimethylsildioxy derivative of the 3-methylether of the steroid. 6. Both rat and rabbit liver slices reduced 18-hydroxyoestrone to 18-hydroxyoestradiol-17β and some other labile, polar metabolites with properties similar to 2-hydroxylated oestrogens. No formation of 18-hydroxyoestradiol-17α in vitro was observed. 7. The results are discussed with respect to the possible influence of the 18-hydroxyl group on reactions at C-17, as well as the reactions of 18-hydroxylated oestrogens with strong acid (Kober reactions) and alkali.

Mass spectrometric studies. X. Phenacylpyridinium enol-betaines

1972 ◽  
Vol 25 (2) ◽  
pp. 345 ◽  
Author(s):  
IC Calder ◽  
QN Porter ◽  
CM Richards
Keyword(s):  
Hydrogen Atom ◽  
Mass Spectra ◽  
Parent Compound ◽  
Molecular Ions ◽  
Mass Spectrometric ◽  
Deuterium Labelling ◽  
E 92

Phenylpyridinium enol-betaines have mass spectra containing abundant molecular ions which decompose by loss of a hydrogen atom to give intense M- 1 species. Both ions eliminate CO and CHO units, and the courses of the various decompositions have been established by making use of deuterium labelling. The ion at m/e 92 in the spectrum of the parent compound is best described by an azatropylium structure.

The Fragmentation Mechanism of Cyclobutanol

1973 ◽  
Vol 51 (14) ◽  
pp. 2342-2346 ◽  
Author(s):  
John L. Holmes ◽  
Robin T. B. Rye
Keyword(s):  
Hydrogen Atom ◽  
Mass Spectra ◽  
Fragmentation Mechanism ◽  
Hydrogen Atoms ◽  
Specific Mechanism ◽  
Molecular Ion ◽  
Random Manner ◽  
Hydroxyl Hydrogen

The mass spectra of cyclobutanol and three 2H labelled analogs have been studied. The losses of C2H4 and C2H5• from the molecular ion involve specific fragmentations. Only CH3• loss from the α-cleaved molecular ion2 clearly involves hydrogen atom scrambling; this fragmentation also proceeds by a specific mechanism involving C-2 and hydroxyl hydrogen atoms. Loss of water from the molecular ion involves all the hydrogen atoms but in a complex, non-random manner.

Activation of the Hydrogen-Terminated Diamond [100] by Hydrogen Atoms and Hydroxyl Groups

2020 ◽  
Vol 996 ◽  
pp. 151-156
Author(s):  
Xiao Gang Jian ◽  
Ji Bo Hu ◽  
Xin Huang ◽  
Pei Kang Yang ◽  
Jun Peng Wang
Keyword(s):  
Hydrogen Atom ◽  
Low Temperature ◽  
Density Functional ◽  
Diamond Surface ◽  
Hydroxyl Group ◽  
Hydroxyl Groups ◽  
Hydrogen Atoms ◽  
Activation Rate ◽  
Limiting Stage ◽  
Rate Limiting

The process of producing active vacancies on a hydrogen-terminated diamond surface is the most important rate-limiting stage in CH4/H2 and CH4/H2/CO2 atmospheres. Hydrogen atom and the hydroxyl group can bone to the hydrogen atom on the diamond surface and create an active vacancy. Density functional theory (DFT) was used to study the extraction reaction by two reactants both hydrogen atom and the hydroxyl group. The result indicated that the hydroxyl group could reduce the energy required for diamond surface activation. What is more, the activation rate of the surface by the hydroxyl group was livelier at low temperature, while the activation rate of the hydrogen atom predicts on the contrary. The scanning electron microscope (SEM) and Raman spectra demonstrated that the introduction of CO2 in the CH4/H2 atmosphere could reduce the deposition temperature and raise the deposition rate at low temperature.

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