Bi-P Bond Homolysis as a Route to Reduced Bismuth Compounds and Reversible Activation of P4

Bismuth diphenylphosphanides Bi(NONR)(PPh2) (NONR=[O(SiMe2NR)(2)], R=tBu, 2,6-iPr(2)C(6)H(3), Aryl) undergo facile decomposition via single-electron processes to form reduced Bi and P species. The corresponding derivatives Bi(NONR)(PCy2) are stable. Reaction of the isolated Bi-II radical Bi-center dot(NONAr) with white phosphorus (P-4) proceeds with the reversible and selective activation of a single P-P bond to afford the bimetallic mu,eta(1:1)-bicyclo[1.1.0]tetraphosphabutane compound.