Linearly‐fused polyarenes are an important class of compounds with high relevance in materials science. While modifying the shape and size represents a common means to fine‐tune their properties, the precise placement of heteroatoms is a strategy that is receiving an increasing deal of attention to overcome the intrinsic limitations of all‐carbon structures. Thus, linearly‐fused diphosphaarenes recently emerged as a novel family of molecules with striking optoelectronic properties and outstanding stability. However, the properties of diphosphaarenes are far from being benchmarked. Herein, we report the synthesis, phosphorus post‐functionalization and properties of new diphosphapentaarene derivatives. We describe their synthetic limitations and unveil their potential for optoelectronic applications.