In this thesis, first, the self-assembly features of the dithienophosphole system were explored by controlling the structural features of the compounds. By varying different directing forces and tuning their strength, a wide variety of self-assembly motifs with interesting optoelectronic features was achieved. Second, the unique chemistry involving the exocyclic R substituent at the phosphorus centre of the phosphole was discussed. Direct functionalization of the phosphole post ring closing can be achieved conveniently through newly synthesized chlorophosphole precursors. Furthermore, an unprecedented method for the construction of P-P single bond was discussed in mechanistic detail.