Codetermination of the composition of monomethyl-substituted and isoprenane alkyl fragments of saturated petroleum hydrocarbons by the 13C NMR technique

Smirnov, M. B.; Melikhov, V. A.; Vanyukova, N. A.

doi:10.1134/s0965544108050022

Cited by 5 publications

(11 citation statements)

References 13 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2). Thus, it is reasonable to assume that these pairs are resonances of the corresponding C atoms of certain k,(k + 3)Me 2 substituted alkyl structure ele ments (SETs; for the concept of the structure element see [7,8]) k,(k + 3)Me 2 -Alk, k ≥ 3.…”

Section: Resultsmentioning

confidence: 99%

“…According to the previously introduced notation system [9], the effect of the methyl substituent in the k position of the chain on δ of the C atom separated from the С k by i С⎯С bonds,…”

Section: Resultsmentioning

confidence: 99%

“…Using the additive scheme of calculation of chem ical shifts, which takes into account their dependence on T rec , C, and sample composition [4], we calculated for the two diastereomers with k = 3-7 and >7 the average δ values of signals of all C atoms separated from one of the chiral centers by no more than two C-C bonds.…”

Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

“…Finally, the structure is established by adding model compounds to the fraction and comparing the spectra before and after their admixture. However, it was shown [3][4][5] that the coefficients for the following equation are also characteristic quantities for each sig nal i: (1) they define the dependence of chemical shifts on both the recording temperature and the concentration of the fraction in solution or, more exactly, on their effec tive values (T eff , C eff ). It was shown that the use of this set of numerical characteristics of each signal can sig nificantly extend the opportunities for finding new groups of saturated cyclic compounds in crude oils by 13 C NMR spectroscopy, making it unnecessary to syn thesize model compounds in certain cases [5].…”

mentioning

confidence: 99%

See 4 more Smart Citations

A 13C NMR study of crude oils: Identification of compounds with nonisoprenane k,(k + 3)-dimethylalkyl moieties in oils and bitumenoids from the southern part of Anadyr basin

Smirnov¹,

Poludetkina

Vanyukova³

2012

Pet. Chem.

Self Cite

View full text Add to dashboard Cite

The standard scheme of identification in mixtures of components with unknown structure on the basis of 13 C NMR data uses the only structure dependent parameter, the chemical shift (δ) of an NMR signal. The scheme includes the following sequence of oper ations. By spectral editing techniques (APT, DEPT, etc.), resonances are attributed to the СН 3 , СН 2 , or CH groups. Possible attribution of the signals and, hence, the structure of the molecule are hypothesized on the basis of published data, results of calculations of chemical shifts by additive schemes (e.g., such as described in [1, 2]), and a priori considerations. Finally, the structure is established by adding model compounds to the fraction and comparing the spectra before and after their admixture. However, it was shown [3][4][5] that the coefficients for the following equation are also characteristic quantities for each sig nal i:they define the dependence of chemical shifts on both the recording temperature and the concentration of the fraction in solution or, more exactly, on their effec tive values (T eff , C eff ). It was shown that the use of this set of numerical characteristics of each signal can sig nificantly extend the opportunities for finding new groups of saturated cyclic compounds in crude oils by 13 C NMR spectroscopy, making it unnecessary to syn thesize model compounds in certain cases [5]. In this paper, we demonstrate the effectiveness and simplicity of this method as applied to searching for alkyl struc tures that have not been previously identified in crude oils and DOM. EXPERIMENTALThe 13 C NMR spectra of fractions in deuterated chloroform (100.6 MHz) with broadband (BB) proton decoupling were recorded on a Bruker DRX 400 spec trometer (Germany) without sample spinning in the same modes (1 and 2) as in [5]. Chemical shifts, in accordance with [3], were counted from the signal of the terminal methyl group of n alkyl moieties, assum ing it to be δ = 14.070 ppm for all recording tempera tures (Т rec ) and concentrations (С) of solutions. To iso late the subspectra of СН 2 and CH + СН 3 groups, a pair of spectra was used: one was with the standard APT pulse width sequence and the other was the "pseudo BB" spectrum with the same wait times and the scanning pulsewidth as those of the first spectrum. Previously, it was shown with the use of model com pounds and specially selected fractions that there is no distortion of the relative integral intensities of signals within the range of each subspectrum (obtained by addition and subtraction of the induced signal decays for these pairs). The relative overlap of subspectra (e.g., the residual intensity of the resonances of CH groups in the subspectrum of СН 2 groups) was less than 1 rel. %.Saturated hydrocarbon (paraffin-cycloparaffin, PCP) fractions were obtained by column chromatog raphy (sorbent, Silperl 40/100 silica gel; eluent, n Abstract-A group of saturated nonisoprenane dimethyl branched, alkyl substituted hydrocarbons of the R CCCCCC(C)CCC(C)CCCCC R' type has been found for the fir...

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 3 more Smart Citations

A 13C NMR study of crude oils: Identification of compounds with nonisoprenane k,(k + 3)-dimethylalkyl moieties in oils and bitumenoids from the southern part of Anadyr basin

Smirnov¹,

Poludetkina

Vanyukova³

2012

Pet. Chem.

Self Cite

View full text Add to dashboard Cite

show abstract

Solid phase extraction of tritiated contaminants from tritium-containing waste oils

Olejniczak

Fall

Olejniczak

et al. 2016

J Radioanal Nucl Chem

View full text Add to dashboard Cite

A solid phase extraction method for removing polar tritiated contaminants from tritium-containing waste oils has been developed. The composition of the degradation products present in the waste oil was determined. The results indicated that upon exposure to tritium gas, fragment methyl ketones, carboxylic acids, and lactones were the main polar products of the mineral-based oil oxidation. The nonpolar fragmentation products included n-alkanes, monomethylalkanes, and acyclic isoprenoids and were analogous to those formed during -irradiation of the oil. Various polar and nonpolar fragmentation products containing an isoprenoid skeleton were found to be formed via an oxidative/radiation scission of long-chain acyclic isoprenoids.Electronic supplementary materialThe online version of this article (doi:10.1007/s10967-016-4953-8) contains supplementary material, which is available to authorized users.

show abstract

The radiation-induced fragmentation of high-molecular-weight isoprenoid hydrocarbons present in high-boiling petroleum fractions

Olejniczak

Шостенко

2018

Radiation Physics and Chemistry

View full text Add to dashboard Cite

Codetermination of the composition of monomethyl-substituted and isoprenane alkyl fragments of saturated petroleum hydrocarbons by the 13C NMR technique

Cited by 5 publications

References 13 publications

A 13C NMR study of crude oils: Identification of compounds with nonisoprenane k,(k + 3)-dimethylalkyl moieties in oils and bitumenoids from the southern part of Anadyr basin

A 13C NMR study of crude oils: Identification of compounds with nonisoprenane k,(k + 3)-dimethylalkyl moieties in oils and bitumenoids from the southern part of Anadyr basin

Solid phase extraction of tritiated contaminants from tritium-containing waste oils

The radiation-induced fragmentation of high-molecular-weight isoprenoid hydrocarbons present in high-boiling petroleum fractions

Contact Info

Product

Resources

About