@article{LazarevaShainyanKleinpeter2010,
  author    = {Lazareva, Nataliya F. and Shainyan, Bagrat A. and Kleinpeter, Erich},
  title     = {4-Alkyl-2,2,6,6-tetramethyl-1,4,2,6-oxaazadisilinanes : synthesis, structure, and conformational analysis},
  issn      = {0894-3230},
  doi       = {10.1002/Poc.1605},
  year      = {2010},
  abstract  = {4-Alkyl-2,2,6,6-tetramethyl-1,4,2,6-oxaazadisilinanes RN[CH2Si(Me)2]2O [R = Me (1), i-Pr (2)] were synthesized by two methods which provided good yields up to 84\%. Low temperature NMR study of compounds (1) and (2) revealed a frozen ring inversion with the energy barriers of 8.5 and 7.7 kcal/mol at 163 and 143 K, respectively, which is substantially lower than that for their carbon analog, N-methylmorpholine. DFT calculations performed on the example of molecule (1) showed that N-Meax conformer to exist in the sofa conformation with the coplanar fragment C-Si-O-Si-C, and its N-Meeq conformer in a flattened chair conformation.},
  language  = {en}
}
@article{ShainyanUshakovKochetal.2006,
  author    = {Shainyan, Bagrat A. and Ushakov, Igor A. and Koch, Andreas and Kleinpeter, Erich},
  title     = {Stereodynamics of 1-(methylsulfonyl)-3,5-bis(trifluoromethylsulfonyl)-1,3,5-triazinane: Experimental and theoretical analysis},
  doi       = {10.1021/Jo061112x},
  year      = {2006},
  abstract  = {Dynamic NMR of 1-(methylsulfonyl)-3,5-bis(trifluoromethylsulfonyl)-1,3,5-triazinane reveals the existence of three conformers and two dynamic processes: ring inversion and rotation about the N-S bond, both processes having Delta G(double dagger) = 13.5 kcal/mol. An unprecedented large reverse Perlin effect (J(CHax) > J(CHeq)) was found experimentally and calculated theoretically.},
  language  = {en}
}
@article{KirpichenkoKleinpeterShainyan2010,
  author    = {Kirpichenko, Svetlana V. and Kleinpeter, Erich and Shainyan, Bagrat A.},
  title     = {Conformational analysis of 3,3-dimethyl-3-silathiane, 2,3,3-trimethyl-3-silathiane and 2-trimethylsilyl-3,3- dimethyl-3-silathiane{\`u}preferred conformers, barriers to ring inversion and substituent effec},
  issn      = {0894-3230},
  year      = {2010},
  abstract  = {The first conformational analysis of 3-silathiane and its C-substituted derivatives, namely, 3,3-dimethyl-3- silathiane 1, 2,3,3-trimethyl-3-silathiane 2, and 2-trimethylsilyl-3,3-dimethyl-3-silathiane 3 was performed by using dynamic NMR spectroscopy and B3LYP/6-311G(d,p) quantum chemical calculations. From coalescence temperatures, ring inversion barriers ;G; for 1 and 2 were estimated to be 6.3 and 6.8;kcal/mol, respectively. These values are considerably lower than that of thiacyclohexane (9.4;kcal/mol) but slightly higher than the one of 1,1- dimethylsilacyclohexane (5.5;kcal/mol). The conformational free energy for the methyl group in 2 (;;G°;=;0.35;kcal/mol) derived from low-temperature 13C NMR data is fairly consistent with the calculated value. For compound 2, theoretical calculations give ;E value close to zero for the equilibrium between the 2-Meax and 2-Meeq conformers. The calculated equatorial preference of the trimethylsilyl group in 3 is much more pronounced (;;G°;=;1.8;kcal/mol) and the predominance of the 3-SiMe3 eq conformer at room temperature was confirmed by the simulated 1H NMR and 2D NOESY spectra. The effect of the 2-substituent on the structural parameters of 2 and 3 is discussed.},
  language  = {en}
}
@article{KleinpeterBoelkeKoch2010,
  author    = {Kleinpeter, Erich and Boelke, Ute and Koch, Andreas},
  title     = {Subtle Trade-off Existing between (Anti)Aromaticity, Push-Pull Interaction, Keto-Enol Tautomerism, and Steric Hindrance When Defining the Electronic Properties of Conjugated Structures},
  issn      = {1089-5639},
  year      = {2010},
  language  = {en}
}
@article{KleinpeterBoelkeKreicberga2010,
  author    = {Kleinpeter, Erich and Boelke, Ute and Kreicberga, Jana},
  title     = {Quantification of the push-pull character of azo dyes and a basis for their evaluation as potential nonlinear optical materials},
  issn      = {0040-4020},
  year      = {2010},
  abstract  = {The push-pull characters of a large series of donor-acceptor substituted azo dyes{\`u}71 structures in all{\`u}have been quantified by the NN double bond lengths, dNN, the 15N NMR chemical shift differences, ;;15N, of the two nitrogen atoms and the quotient, ;*/;, of the occupations of the antibonding ;*, and bonding ; orbitals of this partial NN double bond. The excellent correlation of the occupation quotients with the bond lengths strongly infers that both ;*/; and dNN are excellent parameters for quantifying charge alternation in the push-pull chromophore and the molecular hyperpolarizability, ;0, of these compounds. By this approach, selected compounds can be appropriately considered as viable candidates for nonlinear optical (NLO) applications.},
  language  = {en}
}
@article{KleinpeterKoch2010,
  author    = {Kleinpeter, Erich and Koch, Andreas},
  title     = {Identification of benzenoid and quinonoid structures by through-space NMR shieldings (TSNMRS)},
  issn      = {1089-5639},
  year      = {2010},
  language  = {en}
}
@article{KramerKleinpeter2010,
  author    = {Kramer, Markus and Kleinpeter, Erich},
  title     = {STD-DOSY : a new NMR method to analyze multi-component enzyme/substrate systems},
  issn      = {1090-7807},
  doi       = {10.1016/j.jmr.2009.11.007},
  year      = {2010},
  abstract  = {A new approach to analyze multi-component Saturation Transfer Difference (STD) NMR spectra by combining the STD and the DOSY experiment is proposed. The resulting pulse sequence was successfully used to simplify an exemplary multi- component protein/substrate system by means of standard DOSY processing methods. Furthermore, the same experiment could be applied to calculate the ratio of saturated substrate molecules and its saturation rate in the case of competitive interactions. This ratio depends on the strength of this interaction between the substrates and the protein, so that this kind of information could be extracted from the results of our experiment.},
  language  = {en}
}
@article{KleinpeterKoch2010,
  author    = {Kleinpeter, Erich and Koch, Andreas},
  title     = {Probing the exohedral magnetic properties of C20 derivatives by through space NMR shieldings (TSNMRS)},
  issn      = {0166-1280},
  doi       = {10.1016/j.theochem.2009.09.018},
  year      = {2010},
  abstract  = {The through space NMR shieldings (TSNMRS) of dodecahedrane C20H20, of the isomeric hydrocarbons C20H12, of the ions C20H122+ and C20H122- of the fluxional fullerene C20 and of its dication C202+ have been ab initio calculated employing the NICS concept on basis of MP2/6-31G* geometries and visualized as iso-chemical-shielding/deshielding surfaces (ICSSs). TSNMRS values were employed to study the exohedral magnetic properties of the compounds studied. Hereby, the curved It-conjugation in the compounds studied could be quantified.},
  language  = {en}
}
@article{KihampaNkunyaJosephetal.2010,
  author    = {Kihampa, Charles and Nkunya, Mayunga H. H. and Joseph, Cosam C. and Magesa, Stephen M. and Hassanali, Ahmed and Heydenreich, Matthias and Kleinpeter, Erich},
  title     = {Antimosquito and antimicrobial clerodanoids and a chlorobenzoid from Tessmannia species},
  issn      = {1934-578X},
  year      = {2010},
  abstract  = {The clerodane diterpenoids trans-kolavenolic acid, 18-oxocleroda-3,13(E)-dien-15-oic acid, ent-(18- hydroxycarbonyl)-cleroda- 3,13(E)-dien-15-oate, 2-oxo-ent-cleroda-3,13(Z)-dien-15-oic acid and trans-2-oxo-ent-cleroda- 13(Z)-en-15-oic acid, and the chlorobenzenoid O-(3-hydroxy-4-hydroxycarbonyl-5-pentylphenyl)-3-chloro-4-methoxy-6-pentyl- 2-oxybenzoic acid were isolated from Tessmannia martiniana var pauloi and T. martiniana var matiniana. Structures were established based on interpretation of spectroscopic data. Some of the compounds exhibited significant antimosquito, antifungal and antibacterial activities.},
  language  = {en}
}
@article{Kleinpeter2007,
  author    = {Kleinpeter, Erich},
  title     = {Syntheses and conformational analyses of mono- and trans-1,4-dialkoxy substituted cyclohexanes : the steric substituent/skeleton interactions},
  issn      = {0040-4020},
  doi       = {10.1016/j.tet.2007.06.094},
  year      = {2007},
  abstract  = {Mono- and trans-1,4-dialkoxy substituted cyclohexanes (alkyl=Me, Et, i-Pr, t-Bu) were prepared using the solvomercuration-demercuration (SM-DM) procedure. The axialaxial and axial,axialequatorial, equatorial conformational equilibria of the products were studied by low temperature 1H and 13C NMR spectroscopy in CD2Cl2. The structures and relative energies of the participating conformers were calculated at both the B3LYP (6-311G*//6-311+G*) and MP2 (6-311+G*//6-311G*) levels of theory. In the case of DFT, good correlations of ;Gocalcd versus ;Goexptl were obtained. Both the structures and the energy differences of the conformers have been discussed with respect to established models of conformational analysis, viz. steric and hyperconjugative interactions. In addition, 1JH,C coupling constants were considered with respect to the hyperconjugation present.},
  language  = {en}
}