Two Different Pathways in the Reduction of [(S=)PCl(μ‐NtBu)]2 with Na

Abstract

Reduction of the cyclodiphosphazane [(S=)ClP(μ‐NtBu)]2 (1) with sodium metal in refluxing toluene proceeds via two different pathways. One is a Wurtz‐type pathway involving elimination of NaCl from 1 followed by head‐to‐tail cyclization to give the hexameric macrocycle [(μ‐S)P(μ‐NtBu)2P(=S)]6 (2). The other pathway involves reduction of the P=S bonds of 1 to generate colorless singlet biradicaloid dianion trans‐[S−P(Cl)(μ‐NtBu)]22−, which is observed in the polymeric structures of three‐dimensional [{(S−)ClP(μ‐NtBu)2PCl(S)}Na(Na⋅THF2)]n (3) and two dimensional [{(S−)ClP(μ‐NtBu)2PCl(S)} (Na⋅THF)2]n (4).