TY  - JOUR
AU  - Valentić, Nataša
AU  - Vitnik, Željko
AU  - Kozhushkov, Sergei I.
AU  - de Meijere, Armin
AU  - Ušćumlić, Gordana
AU  - Juranić, Ivan
PY  - 2005
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/823
AB  - Linear free energy relationships (LFER) were applied to the H-1 and C-13 NMR chemical shifts (delta(N), N=H-1 and C-13, respectively) in the unsaturated backbone of cross-conjugated trienes 3-methylene-2-substituted-1,4-pentadienes. The NMR data were correlated using five different LFER models, based on the mono, the dual and the triple substituent parameter (MSP, DSP and TSP, respectively) treatment. The simple and extended Hammett equations, and the three postulated unconventional LFER models obtained by adaptation of the later, were used. The geometry data, which are needed in Karplus-type and McConnell-type analysis, were obtained using semi-empirical MNDO-PM3 calculations. In correlating the data the TSP approach was more successful than the MSP and DSP approaches. The fact that the calculated molecular geometries allow accurate prediction of the NMR data confirms the validity of unconventional LFER models used. These results suggest the s-cis conformation of the cross-conjugated triene as the preferred one. Postulated unconventional DSP and TSP equations enable the assessment of electronic substituent effects in the presence of other interfering influences.
PB  - Elsevier Science Bv, Amsterdam
T2  - Journal of Molecular Structure
T1  - Linear free energy relationships of the H-1 and C-13 NMR chemical shifts of 3-methylene-2-substituted-1,4-pentadienes
EP  - 908
SP  - 901
VL  - 744
DO  - 10.1016/j.molstruc.2004.12.014
ER  - 

@article{
author = "Valentić, Nataša and Vitnik, Željko and Kozhushkov, Sergei I. and de Meijere, Armin and Ušćumlić, Gordana and Juranić, Ivan",
year = "2005",
abstract = "Linear free energy relationships (LFER) were applied to the H-1 and C-13 NMR chemical shifts (delta(N), N=H-1 and C-13, respectively) in the unsaturated backbone of cross-conjugated trienes 3-methylene-2-substituted-1,4-pentadienes. The NMR data were correlated using five different LFER models, based on the mono, the dual and the triple substituent parameter (MSP, DSP and TSP, respectively) treatment. The simple and extended Hammett equations, and the three postulated unconventional LFER models obtained by adaptation of the later, were used. The geometry data, which are needed in Karplus-type and McConnell-type analysis, were obtained using semi-empirical MNDO-PM3 calculations. In correlating the data the TSP approach was more successful than the MSP and DSP approaches. The fact that the calculated molecular geometries allow accurate prediction of the NMR data confirms the validity of unconventional LFER models used. These results suggest the s-cis conformation of the cross-conjugated triene as the preferred one. Postulated unconventional DSP and TSP equations enable the assessment of electronic substituent effects in the presence of other interfering influences.",
publisher = "Elsevier Science Bv, Amsterdam",
journal = "Journal of Molecular Structure",
title = "Linear free energy relationships of the H-1 and C-13 NMR chemical shifts of 3-methylene-2-substituted-1,4-pentadienes",
pages = "908-901",
volume = "744",
doi = "10.1016/j.molstruc.2004.12.014"
}

Valentić, N., Vitnik, Ž., Kozhushkov, S. I., de Meijere, A., Ušćumlić, G.,& Juranić, I.. (2005). Linear free energy relationships of the H-1 and C-13 NMR chemical shifts of 3-methylene-2-substituted-1,4-pentadienes. in Journal of Molecular Structure
Elsevier Science Bv, Amsterdam., 744, 901-908.
https://doi.org/10.1016/j.molstruc.2004.12.014

Valentić N, Vitnik Ž, Kozhushkov SI, de Meijere A, Ušćumlić G, Juranić I. Linear free energy relationships of the H-1 and C-13 NMR chemical shifts of 3-methylene-2-substituted-1,4-pentadienes. in Journal of Molecular Structure. 2005;744:901-908.
doi:10.1016/j.molstruc.2004.12.014 .

Valentić, Nataša, Vitnik, Željko, Kozhushkov, Sergei I., de Meijere, Armin, Ušćumlić, Gordana, Juranić, Ivan, "Linear free energy relationships of the H-1 and C-13 NMR chemical shifts of 3-methylene-2-substituted-1,4-pentadienes" in Journal of Molecular Structure, 744 (2005):901-908,
https://doi.org/10.1016/j.molstruc.2004.12.014 . .

TY  - JOUR
AU  - Valentić, Nataša
AU  - Vitnik, Željko
AU  - Kozhushkov, Sergei I.
AU  - de Majere, Armin
AU  - Ušćumlić, Gordana
AU  - Juranić, Ivan
PY  - 2003
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/574
AB  - The principles of linear free energy relationships were applied to the 13C substituent chemical shifts (SCS) of the carbon atoms in the unsaturated chain of 3-methylene-4-substituted-1,4-pentadienes. Correlations of the SCS with the substituent parameters of Swain and Lupton provide a mutually consistent picture of the electronic effects in these compounds. The pattern of the electronic effects can be fully rationalized by a model based on the direct transmission of substituent effects through-space (direct through-space field effects), and via conjugative interactions (resonance effects), or by substituent-induced polarization of the ¶-system in the unsaturated chain (¶-polarization effect). Semi-empirical MNDO-PM3 calculations suggest the s-cis conformation of 3-methylene-4-substituted-1,4-pentadienes as the one with minimal heat of formation.
AB  - Na 13C supstituentska hemijska pomeranja (SHP) ugljenikovih atoma u nezasićenom lancu 3-metilen-4-supstituisanih-1,4-pentadiena su primenjeni principi linearne korelacije slobodne energije. Korelacije SHP sa supstituentskim parametrima Swain-a i Lupton-a pružaju usaglašenu sliku elektronskih efekata u ovim jedinjenjima. Koncept elektronskih efekata može u potpunosti biti objašnjen modelom koji se zasniva na direktnom prenošenju efekata supstituenata kroz prostor (direktni efekti polja kroz prostor) i preko konjugacionih interakcija (rezonancioni efekti), ili putem supstituentom izazvane polarizacije ¶-sistema u nezasićenom lancu (efekti ¶-polarizacije). MNDO-PM3 semiempirijska izračunavanja upućuju na s-cis konformaciju 3-metilen-4-supstituisanih-1,4-pentadiena kao konformaciju sa minimalnom energijom obrazovanja.
PB  - Serbian Chemical Society, Belgrade
T2  - Journal of the Serbian Chemical Society
T1  - Effect of substituents on the 13C-NMR chemical shifts of 3-methylene-4-substituted-1, 4-pentadienes - Part I
T1  - Efekti supstituenata na 13C-NMR hemijska pomeranja 3-metilen-4-supstituisanih-1,4-pentadiena - deo I
EP  - 76
IS  - 2
SP  - 67
VL  - 68
UR  - https://hdl.handle.net/21.15107/rcub_technorep_574
ER  - 

@article{
author = "Valentić, Nataša and Vitnik, Željko and Kozhushkov, Sergei I. and de Majere, Armin and Ušćumlić, Gordana and Juranić, Ivan",
year = "2003",
abstract = "The principles of linear free energy relationships were applied to the 13C substituent chemical shifts (SCS) of the carbon atoms in the unsaturated chain of 3-methylene-4-substituted-1,4-pentadienes. Correlations of the SCS with the substituent parameters of Swain and Lupton provide a mutually consistent picture of the electronic effects in these compounds. The pattern of the electronic effects can be fully rationalized by a model based on the direct transmission of substituent effects through-space (direct through-space field effects), and via conjugative interactions (resonance effects), or by substituent-induced polarization of the ¶-system in the unsaturated chain (¶-polarization effect). Semi-empirical MNDO-PM3 calculations suggest the s-cis conformation of 3-methylene-4-substituted-1,4-pentadienes as the one with minimal heat of formation., Na 13C supstituentska hemijska pomeranja (SHP) ugljenikovih atoma u nezasićenom lancu 3-metilen-4-supstituisanih-1,4-pentadiena su primenjeni principi linearne korelacije slobodne energije. Korelacije SHP sa supstituentskim parametrima Swain-a i Lupton-a pružaju usaglašenu sliku elektronskih efekata u ovim jedinjenjima. Koncept elektronskih efekata može u potpunosti biti objašnjen modelom koji se zasniva na direktnom prenošenju efekata supstituenata kroz prostor (direktni efekti polja kroz prostor) i preko konjugacionih interakcija (rezonancioni efekti), ili putem supstituentom izazvane polarizacije ¶-sistema u nezasićenom lancu (efekti ¶-polarizacije). MNDO-PM3 semiempirijska izračunavanja upućuju na s-cis konformaciju 3-metilen-4-supstituisanih-1,4-pentadiena kao konformaciju sa minimalnom energijom obrazovanja.",
publisher = "Serbian Chemical Society, Belgrade",
journal = "Journal of the Serbian Chemical Society",
title = "Effect of substituents on the 13C-NMR chemical shifts of 3-methylene-4-substituted-1, 4-pentadienes - Part I, Efekti supstituenata na 13C-NMR hemijska pomeranja 3-metilen-4-supstituisanih-1,4-pentadiena - deo I",
pages = "76-67",
number = "2",
volume = "68",
url = "https://hdl.handle.net/21.15107/rcub_technorep_574"
}

Valentić, N., Vitnik, Ž., Kozhushkov, S. I., de Majere, A., Ušćumlić, G.,& Juranić, I.. (2003). Effect of substituents on the 13C-NMR chemical shifts of 3-methylene-4-substituted-1, 4-pentadienes - Part I. in Journal of the Serbian Chemical Society
Serbian Chemical Society, Belgrade., 68(2), 67-76.
https://hdl.handle.net/21.15107/rcub_technorep_574

Valentić N, Vitnik Ž, Kozhushkov SI, de Majere A, Ušćumlić G, Juranić I. Effect of substituents on the 13C-NMR chemical shifts of 3-methylene-4-substituted-1, 4-pentadienes - Part I. in Journal of the Serbian Chemical Society. 2003;68(2):67-76.
https://hdl.handle.net/21.15107/rcub_technorep_574 .

Valentić, Nataša, Vitnik, Željko, Kozhushkov, Sergei I., de Majere, Armin, Ušćumlić, Gordana, Juranić, Ivan, "Effect of substituents on the 13C-NMR chemical shifts of 3-methylene-4-substituted-1, 4-pentadienes - Part I" in Journal of the Serbian Chemical Society, 68, no. 2 (2003):67-76,
https://hdl.handle.net/21.15107/rcub_technorep_574 .