Fundamental research is key important to allow us to find new, economically and ecologically attractive ways to meet current challenges. The current depletion of available phosphorus resources is a concern. Unlike oil, which is lost once used, phosphorus can be recovered and used over and over again or at least transformed into other compounds of chemical use. The intention of the present research proposal is to contribute to the field of synthetic chemistry both, inorganic and organic, by identifying and developing highly-reactive phosphorus building blocks that can be potentially regenerated. We would like to enter new avenues of phosphorus chemistry which will address fundamental questions and develop new applications. Using novel and powerful phosphorus reagents, new concepts for more efficient, selective and sustainable synthetic procedures will be developed. We also seek greener and more efficient processes and, whenever possible, to recover the phosphorus after the reaction. Phosphorus-based compounds will also be used in the recovery of industrial waste by-products such as phosphane oxides and depleted UF6, and will therefore have a positive impact on certain chemical industries and the environment.With our proposal we aim to address the following aspects:1) Synthesis of N-heterocyclic pnictanes (Pn = P, As, Sb, Bi with emphasis on P) and related cationic derivatives2) Exploration of N-heterocyclic phosphanes as reagents in organic synthesis.3) Preparation of catenated, branched and cyclic polyphosphanes via a novel method for P–P bond formation – access tonovel polyphosphorus-based ligand systems.4) Alternative processes for the recycling of UF6 and related derivatives to access novel precursors for uranium chemistryand to recover fluorine based products of high economic value.