The field of single molecule electronics research has been spurred by the need to add functionality to next-generation electronic circuits and the desire to miniaturize devices. We focused on some acenebased molecular junctions, in which molecules are connected to Au electrodes via anchor groups. The frontier molecular orbitals (FMOs) and charge transport nature of the junction were examined by employing the density functional theory (DFT) in conjunction with the non-equilibrium Green's functional (NEGF) formalism. Particular attention was paid to the anchoring groups (NH2, S, CN, and SH), chemical impurity doping (B, N, and NB), and side groups (-CH3, -NH2, and –NO2). The findings demonstrate that the FMOs can change depending on the dopants or substituents employed. Additionally, it is noted that depending on the materials employed, charge transfer may be p-type or ntype. It is discovered that the molecular junctions have the highest conductivity when cyanides are used as anchor groups. It is therefore the ideal anchor material to utilize with tetracene and pentacene molecules. Understanding and creating n-type or p-typed high conductivity single molecule electronic components can be greatly aided by these discoveries.