بخشی از متن دانلود فایل مقاله Theoretical study of - stacking interactions in substituted-coronene||cyclooctatetraene complexes: A system without direct electrostatic effects of substituents :
سال انتشار : 2015
تعداد صفحات :17
Stability of the ;-; stacking interactions in the substituted-coronene||cyclooctatetraene complexes wasstudied using the computational quantum chemistry methods (where || denotes ;–; stackinginteraction, and substituted-coronene is coronene which substituted with four similar X groups; X =OH, SH, H, F, CN, and NO). There are meaningful correlations between changes of geometricalparameters and topological properties of the electron charge densities at ring critical points due toformation of complexes and ;-; stacking binding energies. In these complexes both electronwithdrawingand electron-donating substituents lead to larger binding energies compared to X = H(unsubsitituetted-coronene||cyclooctatetraene complex).This finding was interpreted on the basis ofNMR data, especially spin-spin coupling constants between C atoms of cyclooctatetraene and C atomsat central rings of substituted-coronenes. Herein, relationships between the ;–; stacking bindingenergy (-E) values and, through-space C-C spin-spin coupling constants (JC-C) in the substitutedcoronene||cyclooctatetraene complexes has been investigated in the complexes without directelectrostatic effects of substituents.