caa a22 4500 465807488 CHVBK 20180323112107.0 cr unu---uuuuu 170327e19900701xx s 000 0 eng 10.1007/BF00530428 doi (NATIONALLICENCE)springer-10.1007/BF00530428 Quantum-chemical calculation of the factors determining interaction forces in monosubstituted methanes [Elektronische Daten] [I. Tupitsyn, Yu. Puzanov, A. Shibaev] On the basis of non-empirical calculations in the basis 3-21GF and semiempirical calculations by the MINDO/3 method we have considered the factors responsible for changes in the force constant of the CH bond (KCH) in molecules of the type CH3X (X = NH2, OH, F, Cl, CN, NC). Analysis of the "orbital strengths,” which determine the value of KCH, shows that for molecules of symmetry C3V the most important contributions come from electrons in MO of the π type. In such molecules the methyl group exhibits a hyperconjugation effect through its group of quasi-π orbitals. The qualitative picture of electronic effects on the value of KCH, obtained by resolving the total valency deformation forces into their components by the method of Fisher and Kollmar, agrees on the whole with the results obtained by treatment in terms of orbitals. It was found that in a number of methane derivatives, including molecules with CS symmetry, the value of KCH is influenced by non-valency interactions as well as by hyperconjugative effects. Plenum Publishing Corporation, 1990 Tupitsyn I. State Institute of Applied Chemistry, Leningrad aut Puzanov Yu State Institute of Applied Chemistry, Leningrad aut Shibaev A. State Institute of Applied Chemistry, Leningrad aut Theoretical and Experimental Chemistry Kluwer Academic Publishers-Plenum Publishers 25/4(1990-07-01), 378-383 0040-5760 25:4<378 1990 25 11237 https://doi.org/10.1007/BF00530428 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF00530428 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Tupitsyn I. State Institute of Applied Chemistry, Leningrad aut NATIONALLICENCE 700 1- Puzanov Yu State Institute of Applied Chemistry, Leningrad aut NATIONALLICENCE 700 1- Shibaev A. State Institute of Applied Chemistry, Leningrad aut NATIONALLICENCE 773 0- Theoretical and Experimental Chemistry Kluwer Academic Publishers-Plenum Publishers 25/4(1990-07-01), 378-383 0040-5760 25:4<378 1990 25 11237 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer