Quantification of the push-pull effect in 2-alkylidene-4-oxothiazolidines by using NMR spectral data and barriers to rotation around the C=C bond
Samo za registrovane korisnike
2016
Autori
Rašović, AleksandarBlagojević, Vladimir A.
Baranac-Stojanović, Marija
Kleinpeter, Erich
Marković, Rade
Minić, Dragica M.
Članak u časopisu (Objavljena verzija)
Metapodaci
Prikaz svih podataka o dokumentuApstrakt
Information about the strength of donor-acceptor interactions in push-pull alkenes is valuable, as this so-called "push-pull effect'' influences their chemical reactivity and dynamic behaviour. In this paper, we discuss the applicability of NMR spectral data and barriers to rotation around the CQC double bond to quantify the push-pull effect in biologically important 2-alkylidene-4-oxothiazolidines. While olefinic proton chemical shifts and differences in C-13 NMR chemical shifts of the two carbons constituting the CQC double bond fail to give the correct trend in the electron withdrawing ability of the substituents attached to the exocyclic carbon of the double bond, barriers to rotation prove to be a reliable quantity in providing information about the extent of donor-acceptor interactions in the push-pull systems studied. In particular all relevant kinetic data, that is the Arrhenius parameters ( apparent activation energy Ea and frequency factor A) and activation parameters ( Delta... S-double dagger, Delta H-double dagger and Delta G(double dagger)), were determined from the data of the experimentally studied configurational isomerization of ( E)-9a. These results were compared to previously published related data for other two compounds, ( Z)-1b and ( 2E, 5Z)-7, showing that experimentally determined Delta G(double dagger) values are a good indicator of the strength of push-pull character. Theoretical calculations of the rotational barriers of eight selected derivatives excellently correlate with the calculated CQC bond lengths and corroborate the applicability of Delta G(double dagger) for estimation of the strength of the push-pull effect in these and related systems.
Izvor:
New Journal of Chemistry, 2016, 40, 7, 6364-6373Izdavač:
- Royal Soc Chemistry, Cambridge
Finansiranje / projekti:
DOI: 10.1039/c6nj00901h
ISSN: 1144-0546
WoS: 000385869600088
Scopus: 2-s2.0-84979060401
Institucija/grupa
IHTMTY - JOUR AU - Rašović, Aleksandar AU - Blagojević, Vladimir A. AU - Baranac-Stojanović, Marija AU - Kleinpeter, Erich AU - Marković, Rade AU - Minić, Dragica M. PY - 2016 UR - https://cer.ihtm.bg.ac.rs/handle/123456789/1934 AB - Information about the strength of donor-acceptor interactions in push-pull alkenes is valuable, as this so-called "push-pull effect'' influences their chemical reactivity and dynamic behaviour. In this paper, we discuss the applicability of NMR spectral data and barriers to rotation around the CQC double bond to quantify the push-pull effect in biologically important 2-alkylidene-4-oxothiazolidines. While olefinic proton chemical shifts and differences in C-13 NMR chemical shifts of the two carbons constituting the CQC double bond fail to give the correct trend in the electron withdrawing ability of the substituents attached to the exocyclic carbon of the double bond, barriers to rotation prove to be a reliable quantity in providing information about the extent of donor-acceptor interactions in the push-pull systems studied. In particular all relevant kinetic data, that is the Arrhenius parameters ( apparent activation energy Ea and frequency factor A) and activation parameters ( Delta S-double dagger, Delta H-double dagger and Delta G(double dagger)), were determined from the data of the experimentally studied configurational isomerization of ( E)-9a. These results were compared to previously published related data for other two compounds, ( Z)-1b and ( 2E, 5Z)-7, showing that experimentally determined Delta G(double dagger) values are a good indicator of the strength of push-pull character. Theoretical calculations of the rotational barriers of eight selected derivatives excellently correlate with the calculated CQC bond lengths and corroborate the applicability of Delta G(double dagger) for estimation of the strength of the push-pull effect in these and related systems. PB - Royal Soc Chemistry, Cambridge T2 - New Journal of Chemistry T1 - Quantification of the push-pull effect in 2-alkylidene-4-oxothiazolidines by using NMR spectral data and barriers to rotation around the C=C bond VL - 40 IS - 7 SP - 6364 EP - 6373 DO - 10.1039/c6nj00901h ER -
@article{ author = "Rašović, Aleksandar and Blagojević, Vladimir A. and Baranac-Stojanović, Marija and Kleinpeter, Erich and Marković, Rade and Minić, Dragica M.", year = "2016", abstract = "Information about the strength of donor-acceptor interactions in push-pull alkenes is valuable, as this so-called "push-pull effect'' influences their chemical reactivity and dynamic behaviour. In this paper, we discuss the applicability of NMR spectral data and barriers to rotation around the CQC double bond to quantify the push-pull effect in biologically important 2-alkylidene-4-oxothiazolidines. While olefinic proton chemical shifts and differences in C-13 NMR chemical shifts of the two carbons constituting the CQC double bond fail to give the correct trend in the electron withdrawing ability of the substituents attached to the exocyclic carbon of the double bond, barriers to rotation prove to be a reliable quantity in providing information about the extent of donor-acceptor interactions in the push-pull systems studied. In particular all relevant kinetic data, that is the Arrhenius parameters ( apparent activation energy Ea and frequency factor A) and activation parameters ( Delta S-double dagger, Delta H-double dagger and Delta G(double dagger)), were determined from the data of the experimentally studied configurational isomerization of ( E)-9a. These results were compared to previously published related data for other two compounds, ( Z)-1b and ( 2E, 5Z)-7, showing that experimentally determined Delta G(double dagger) values are a good indicator of the strength of push-pull character. Theoretical calculations of the rotational barriers of eight selected derivatives excellently correlate with the calculated CQC bond lengths and corroborate the applicability of Delta G(double dagger) for estimation of the strength of the push-pull effect in these and related systems.", publisher = "Royal Soc Chemistry, Cambridge", journal = "New Journal of Chemistry", title = "Quantification of the push-pull effect in 2-alkylidene-4-oxothiazolidines by using NMR spectral data and barriers to rotation around the C=C bond", volume = "40", number = "7", pages = "6364-6373", doi = "10.1039/c6nj00901h" }
Rašović, A., Blagojević, V. A., Baranac-Stojanović, M., Kleinpeter, E., Marković, R.,& Minić, D. M.. (2016). Quantification of the push-pull effect in 2-alkylidene-4-oxothiazolidines by using NMR spectral data and barriers to rotation around the C=C bond. in New Journal of Chemistry Royal Soc Chemistry, Cambridge., 40(7), 6364-6373. https://doi.org/10.1039/c6nj00901h
Rašović A, Blagojević VA, Baranac-Stojanović M, Kleinpeter E, Marković R, Minić DM. Quantification of the push-pull effect in 2-alkylidene-4-oxothiazolidines by using NMR spectral data and barriers to rotation around the C=C bond. in New Journal of Chemistry. 2016;40(7):6364-6373. doi:10.1039/c6nj00901h .
Rašović, Aleksandar, Blagojević, Vladimir A., Baranac-Stojanović, Marija, Kleinpeter, Erich, Marković, Rade, Minić, Dragica M., "Quantification of the push-pull effect in 2-alkylidene-4-oxothiazolidines by using NMR spectral data and barriers to rotation around the C=C bond" in New Journal of Chemistry, 40, no. 7 (2016):6364-6373, https://doi.org/10.1039/c6nj00901h . .