@article{KleinpeterKlaumuenzer2014,
  author    = {Kleinpeter, Erich and Klaumuenzer, Ute},
  title     = {Quantification of the push-pull Effect in disubstituted alkynes - Application of occupation quotients pi*/pi and C-13 chemical shift differences Delta delta(C C)},
  series = {Journal of molecular structure},
  volume    = {1074},
  journal   = {Journal of molecular structure},
  publisher = {Elsevier},
  address   = {Amsterdam},
  issn      = {0022-2860},
  doi       = {10.1016/j.molstruc.2014.05.072},
  pages     = {193 -- 195},
  year      = {2014},
  abstract  = {Structures, C-13 chemical shifts, and the occupation quotients of anti-bonding pi* and bonding pi orbitals of the C C triple bond along a series of push-pull alkynes (p)X-C6H4 C(O)-C C-NH-C6H4-Y(P) (X,Y= H, Me, OMe, NMe2, NO2, COMe, COOMe, F, Cl, Br) were computed at the DFT level (B3LYP/6-311G**) of theory. Both the stereochemistry (cis/trans-isomers) by steric twist and the push-pull character by both C-13 chemical shift differences (Delta delta(C C)) and the occupation quotient (pi(C C)/pi(C C)) were studied; the latter two parameters can be readily employed to precisely quantify the push-pull effect in alkynes. (C) 2014 Elsevier B.V. All rights reserved.},
  language  = {en}
}
@article{BaranacStojanovicKlaumuenzerMarkovicetal.2010,
  author    = {Baranac-Stojanovic, Marija and Klaumuenzer, Ute and Markovic, Rade and Kleinpeter, Erich},
  title     = {Structure, configuration, conformation and quantification of the push pull-effect of 2-alkylidene-4- thiazolidinones and 2-alkylidene-4,5-fused bicyclic thiazolidine derivatives},
  issn      = {0040-4020},
  doi       = {10.1016/j.tet.2010.09.040},
  year      = {2010},
  abstract  = {Structures of a series of push-pull 2-alkylidene-4-thiazolidinones and 2-alkylidene-4,5-fused bicyclic thiazolidine derivatives were optimized at the B3LYP/6-31G(d) level of theory in the gas phase and discussed with respect to configurational and conformational stability. Employing the GIAO method, C-13 NMR chemical shifts of the C-2, C-2', C-4 and C-5 atoms were calculated at the same level of theory in the gas phase and with inclusion of solvent, and compared with experimental data. Push-pull effect of all compounds was quantified by means of the quotient pi*/pi, length of the partial double bond, C-13 NMR chemical shift difference (Delta delta(C=C)) and H-1 NMR chemical shifts of olefinic protons. The effect of bromine on donating and accepting ability of other substituents of the push- pull C=C double bond is discussed, too.},
  language  = {en}
}