3.5. Powerful charge transport property of DTS structural
modification
Among the previously listed studied compounds, the priority should be
the electronic properties of the dimer compound. At that biased level,
we continuously study the influences of functional groups at
1,1’-positions on DTS-DTS compound 10 , thereby designating four
new compounds 10a-10d as shown in Fig. 6.
Similar to the original compound 10 , frontier molecular orbital
analysis from 10a-10d has resulted in describing that electrons
delocalize over DTS-DTS skeleton in HOMO and LUMO neutral states and
slightly visual concentration in pyridyl group in individual10d (Fig. S3). HOMO energies of designated groups10a-10d are comparable to or higher than that of dimer10 , but LUMO and the band gap energies reach to a remarkable
order of 10a > 10c >10 ≥ 10b > 10d (Table 5). We can
safely manage a good strategy to make lowered LUMO layers and reduce
band gap energies, using SiMe3 and
C5H3SiMe3 groups at
1,1’-positions.
Considering what λh and λe have acquired
so far for charge transport rate. Although the computed values still
have better outcomes than CBP , only two significant features
can be observed: i) the values λh of designated
compounds are scaled down about 2-2.5 folds, relative to originated
agent 10 , and ii) the decline has only occurred in the values
λe of 10a-10b . Nonetheless, the numerous
research that focused on analyzing ionization potential and electron
affinity, as compared with compound 10 , the amount of
IPv/IPa of 10c-10d is lesser,
and compound 10d successfully increases the values
EAv/EAa. Generally, structure
modification happens at 1,1’-positions of DTS-DTS core which would help
to set out to favorable low reorganization energies as expected.
Functional groups are reasonable for drastically hole reorganization
energies reduction, especially in terms of structural expansion,
π-conjugated unit that would help increase electron delocalization and
electron transport capacity in oxidative-reductive stable polymeric
materials.