Exploration of Novel α,ω‐Substituted Diphosphatrisilanes by Combining Experimental Methods and DFT Calculations

The novel diphosphatrisilanes {(R₂P‐Si(SiMe₃)₂‐)₂‐SiMe₂} [R = Ph, H] and the cyclophosphatrisilabutanes {R–PSi₃} [R = H, SiMe₃] have been prepared via salt metathesis reactions between phosphanides and 2,4‐dihalogenated pentasilanes and characterized via NMR spectroscopy. The experimental results were supported by DFT calculations. Although P–Si bond formation was observed in all cases, the outcome of the reactions varied depending on the nature of ligands on the phosphanides, forming either linear diphosphatrisilanes or cyclic phosphatrisilacyclobutanes. DFT studies were performed to get a better understanding of the reactions. The precursor silanes were fully characterized using NMR spectroscopy and single‐crystal X‐ray diffraction and offer interesting building blocks. In addition, a modified route for the synthesis of P(TMS)₃ was successfully carried out, achieving high yields of up to 73 %, circumventing the use of white phosphorus and phosphine gas during the reaction.