“…Scheme 1) such as polyphosphazenes 1,2 have drawn particular notoriety in flame-retardant materials 3 -6 such as derivatives of R1, although they are also commercially employed in optical applications (R2), 7 for glass fiber reinforcement (R3) 8,9 and as finishes for textiles (R4). 10,11 Examples of phosphorus-containing polymers with promise for more recently emerging technologies, such as semiconducting -conjugated polymers incorporating low-coordinate phosphorus centers, have also been reported. 12 -14 Phosphines are among the best-studied ligands for coordination chemistry and catalysis, and have thus naturally drawn attention as elements of coordination polymers as well.…”