Raman signatures of alkyl chain length: Comparative analysis of 1-alkanols and normal alkanes
The comparative experimental and density functional theory studies of Raman spectra of 1-alkanols (CnH2n+1OH with n = 2–16) and n-alkanes (CnH2n+2 with n = 5–24) are presented. Three collective vibrations (LAM, D-LAM and symmetric C–C stretching mode), which are sensitive to the molecular chain leng...
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Elsevier
2024-01-01
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| Series: | Results in Chemistry |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2211715623005325 |
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| author | Vladimir V. Kuzmin Sergey M. Kuznetsov Vasiliy S. Novikov Leila Yu. Ustynyuk Pavel V. Ivchenko Gulnara Yu. Nikolaeva Elena A. Sagitova |
| author_facet | Vladimir V. Kuzmin Sergey M. Kuznetsov Vasiliy S. Novikov Leila Yu. Ustynyuk Pavel V. Ivchenko Gulnara Yu. Nikolaeva Elena A. Sagitova |
| author_sort | Vladimir V. Kuzmin |
| collection | DOAJ |
| description | The comparative experimental and density functional theory studies of Raman spectra of 1-alkanols (CnH2n+1OH with n = 2–16) and n-alkanes (CnH2n+2 with n = 5–24) are presented. Three collective vibrations (LAM, D-LAM and symmetric C–C stretching mode), which are sensitive to the molecular chain length, were found in the Raman spectra of 1-alkanols with n ≥ 4. The evolutions of these modes with the change of the chain length of 1-alkanol molecule were analyzed.For the first time, we assigned the Raman bands of 1-alkanols in the spectral region of 100–600 cm−1 in terms of the LAM and D-LAM bands. The LAM band is the most intense in this region of the Raman spectra of liquid 1-alkanols with n = 4–6. However, it is masked by D-LAM band, which becomes the most intense for liquid 1-alkanols with n ≥ 7. We found that the following relation between the observed wavenumber (ν) of the D-LAM band and the number of atoms in the molecule backbone, i.e. the chain length of the molecules, can be used to measure the chain length for the 1-alkanols in a liquid phase with n ≥ 7:ν=5590n+12+198cm-1.In the case of liquid 1-alkanols with n = 4–6, the same dependence can be applied. However, it is important to keep in mind another assignment of the most intense band in the region of 100–600 cm−1 in this case: LAM instead of D-LAM.For the first time, we revealed that measurement of the wavenumber (νC–C) of the symmetric C–C stretching mode, localized in the spectral region of 1100–1130 cm−1, allows one to evaluate the chain length of the molecules of liquid and solid 1-alkanols (with n ≤ 16) by using the following relation:νC-C=1134.7-103n+1cm-1. |
| first_indexed | 2024-03-08T17:06:36Z |
| format | Article |
| id | doaj.art-22c3fa0722b34a61917305206b7dcf25 |
| institution | Directory Open Access Journal |
| issn | 2211-7156 |
| language | English |
| last_indexed | 2024-03-08T17:06:36Z |
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| spelling | doaj.art-22c3fa0722b34a61917305206b7dcf252024-01-04T04:39:24ZengElsevierResults in Chemistry2211-71562024-01-017101293Raman signatures of alkyl chain length: Comparative analysis of 1-alkanols and normal alkanesVladimir V. Kuzmin0Sergey M. Kuznetsov1Vasiliy S. Novikov2Leila Yu. Ustynyuk3Pavel V. Ivchenko4Gulnara Yu. Nikolaeva5Elena A. Sagitova6Prokhorov General Physics Institute of the Russian Academy of Sciences, Vavilov Str. 38, 119991 Moscow, RussiaProkhorov General Physics Institute of the Russian Academy of Sciences, Vavilov Str. 38, 119991 Moscow, Russia; Corresponding authors.Prokhorov General Physics Institute of the Russian Academy of Sciences, Vavilov Str. 38, 119991 Moscow, RussiaDepartment of Chemistry, M.V. Lomonosov Moscow State University, Leninskie Gory 1-3, 119991 Moscow, RussiaDepartment of Chemistry, M.V. Lomonosov Moscow State University, Leninskie Gory 1-3, 119991 Moscow, Russia; A.V. Topchiev Institute of Petrochemical Synthesis of the Russian Academy of Sciences, Leninsky Pr. 29, 119991 Moscow, RussiaProkhorov General Physics Institute of the Russian Academy of Sciences, Vavilov Str. 38, 119991 Moscow, RussiaProkhorov General Physics Institute of the Russian Academy of Sciences, Vavilov Str. 38, 119991 Moscow, Russia; Corresponding authors.The comparative experimental and density functional theory studies of Raman spectra of 1-alkanols (CnH2n+1OH with n = 2–16) and n-alkanes (CnH2n+2 with n = 5–24) are presented. Three collective vibrations (LAM, D-LAM and symmetric C–C stretching mode), which are sensitive to the molecular chain length, were found in the Raman spectra of 1-alkanols with n ≥ 4. The evolutions of these modes with the change of the chain length of 1-alkanol molecule were analyzed.For the first time, we assigned the Raman bands of 1-alkanols in the spectral region of 100–600 cm−1 in terms of the LAM and D-LAM bands. The LAM band is the most intense in this region of the Raman spectra of liquid 1-alkanols with n = 4–6. However, it is masked by D-LAM band, which becomes the most intense for liquid 1-alkanols with n ≥ 7. We found that the following relation between the observed wavenumber (ν) of the D-LAM band and the number of atoms in the molecule backbone, i.e. the chain length of the molecules, can be used to measure the chain length for the 1-alkanols in a liquid phase with n ≥ 7:ν=5590n+12+198cm-1.In the case of liquid 1-alkanols with n = 4–6, the same dependence can be applied. However, it is important to keep in mind another assignment of the most intense band in the region of 100–600 cm−1 in this case: LAM instead of D-LAM.For the first time, we revealed that measurement of the wavenumber (νC–C) of the symmetric C–C stretching mode, localized in the spectral region of 1100–1130 cm−1, allows one to evaluate the chain length of the molecules of liquid and solid 1-alkanols (with n ≤ 16) by using the following relation:νC-C=1134.7-103n+1cm-1.http://www.sciencedirect.com/science/article/pii/S2211715623005325Raman spectroscopyLongitudinal acoustic modeDisorder longitudinal acoustic modeC–C modeLength-dependenceDFT |
| spellingShingle | Vladimir V. Kuzmin Sergey M. Kuznetsov Vasiliy S. Novikov Leila Yu. Ustynyuk Pavel V. Ivchenko Gulnara Yu. Nikolaeva Elena A. Sagitova Raman signatures of alkyl chain length: Comparative analysis of 1-alkanols and normal alkanes Results in Chemistry Raman spectroscopy Longitudinal acoustic mode Disorder longitudinal acoustic mode C–C mode Length-dependence DFT |
| title | Raman signatures of alkyl chain length: Comparative analysis of 1-alkanols and normal alkanes |
| title_full | Raman signatures of alkyl chain length: Comparative analysis of 1-alkanols and normal alkanes |
| title_fullStr | Raman signatures of alkyl chain length: Comparative analysis of 1-alkanols and normal alkanes |
| title_full_unstemmed | Raman signatures of alkyl chain length: Comparative analysis of 1-alkanols and normal alkanes |
| title_short | Raman signatures of alkyl chain length: Comparative analysis of 1-alkanols and normal alkanes |
| title_sort | raman signatures of alkyl chain length comparative analysis of 1 alkanols and normal alkanes |
| topic | Raman spectroscopy Longitudinal acoustic mode Disorder longitudinal acoustic mode C–C mode Length-dependence DFT |
| url | http://www.sciencedirect.com/science/article/pii/S2211715623005325 |
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