Fig. 3: Calculated conductance, difference charge density and bond length.

a Calculated conductance of diphenyl [n] conjugated polyene sandwiched between two copper electrodes, as a function of electrode distance (i.e., numbers of carbon atoms in polyene part of molecules (n)). The calculations are performed under bias voltage of 50 meV (blue dot), 100 mV (light red dot) and 200 mV (red dot), with exponential fittings shown as dash lines. The inset presents an example of model used in the calculations, where a single diphenyl [20] conjugated polyene molecule adsorbs on two electrodes via two phenyl groups. Circles color: bronze (copper), gray (carbon), white (hydrogen). b The difference charge density plot for the calculated transport model with diphenyl [20] conjugated polyene with side view and top view. The isosurface value is set as 0.05 e Å⁻¹ at \(\pm\)0.005 a₀⁻³. The symbol a₀ represents the Bohr radius, and a₀⁻³ is a unit of number density, indicating the number of entities per cubic Bohr radius. The arrows indicate the electrons transfer from C = C bonds to C-C bonds. c Structural and bond-length features of diphenyl [20] conjugated polyene. The structure of an individual diphenyl [20] conjugated polyene, its bond length alternation in gas phase and the fading bond length alternation in the calculated transport model are shown in order. Source data are provided as a Source Data file.