Abstract
In order to tune the optoelectronic and charge transfer properties of 4,6-di(thiophen-2-yl)pyrimidine (1), some new compounds were designed, i.e., 4,6-bis(benzo[b]thiophen-2-yl)pyrimidine (2), 4,6-bis(naphtho[2,3-b]thiophen-2-yl)pyrimidine (3), 4,6-bis(anthra[2,3-b]thiophen-2-yl)pyrimidine (4), 4,6-bis(tetraceno[2,3-b]thiophen-2-yl)pyrimidine (5) and 4,6-bis(pentaceno[2,3-b]thiophen-2-yl)pyrimidine (6). Compounds 2-6 were designed by assimilation of benzene, naphthalene, anthracene, tetracene and pentacene, respectively at both ends of compound 1. Integration of oligocene end cores reduces the energy gap resulting in a red shift in the absorption and fluorescence emission spectra. The legible intra-molecular charge transfer is significant from electron-rich moieties to the electron-deficient core (pyrimidine). The elongation of -conjugation led to escalate the electron affinity, lower the ionization potential and hole reorganization energy. The hole reorganization energies of compounds 3-6 exposed that these materials would be effective hole transport contenders to be used in diverse semiconductor devices.