Synthesis and characterization of n-heterocyclic phosphenium and arsenium salts

Two ligand types were employed for the one-step preparations of heavy group 15 cations, namely, diazabutadiene (DAB) and bis(imino)acenaphthene (BIAN). By exploiting the redox properties of these ligands, in conjunction with two different synthetic strategies, it was possible to synthesize a variety of phosphenium and arsenium salts in relatively high yields. The first synthetic method took advantage of the known equilibrium between PI/PI3 in solution. The second synthetic route employed SnCl2 as the reducing agent for converting the reactive trihalides ECl3 into the corresponding “ECl” moieties (E = P, As).