Different mutual positions of double bonds in open carbon chains and corresponding information from magnetically induced current densities

摘要

Magnetically induced current densities have been extensively utilized to investigate aromaticity. However, an applied external magnetic field induces a current in all chemical bonds. The present work investigates the values and patterns of magnetically induced current densities in open hydrocarbon chains containing two or more C(sic)C double bonds, considering the three possibilities for the mutual positions of the double bonds (conjugated, isolated, and consecutive) and comparing the corresponding current patterns. The patterns for chains containing three conjugated double bonds are also compared with the patterns in the aromatic benzene ring. The study highlights different current patterns for the three categories of double-bonds arrangements. The differences can be interpreted in terms of presence or absence of electron delocalization (present only in the case of conjugated double bonds) and, for consecutive double bonds, also in terms of the mutual perpendicularity of the pi orbitals of adjacent double bonds.