An Isolable 2,5‐Disila‐3,4‐Diphosphapyrrole and a Conjugated Si=P−Si=P−Si=N Chain Through Degradation of White Phosphorus with a N,N‐Bis(Silylenyl)Aniline

White phosphorus (P(4)) undergoes degradation to P(2) moieties if exposed to the new N,N‐bis(silylenyl)aniline PhNSi (2) 1 (Si=Si[N(tBu)](2)CPh), furnishing the first isolable 2,5‐disila‐3,4‐diphosphapyrrole 2 and the two novel functionalized Si=P doubly bonded compounds 3 and 4. The pathways for the transformation of the non‐aromatic 2,5‐disila‐3,4‐diphosphapyrrole PhNSi (2)P(2) 2 into 3 and 4 could be uncovered. It became evident that 2 reacts readily with both reactants P(4) and 1 to afford either the polycyclic Si=P‐containing product [PhNSi (2)P(2)](2)P(2) 3 or the unprecedented conjugated Si=P−Si=P−Si=NPh chain‐containing compound 4, depending on the employed molar ratio of 1 and P(4) as well as the reaction conditions. Compounds 3 and 4 can be converted into each other by reactions with 1 and P(4), respectively. All new compounds 1–4 were unequivocally characterized including by single‐crystal X‐ray diffraction analysis. In addition, the electronic structures of 2–4 were established by Density Functional Theory (DFT) calculations.