A Push-Pull Phosphasilene and Phosphagermene and Their Anion-Radicals

Phosphasilene 1a and phosphagermene 1b, featuring unprecendented substitution patterns (donors on Si or Ge and acceptor on P), were synthesized utilizing a one-step synthetic approach; direct coupling of dilithiosilane/dilithiogermane and dichlorophosphine. The structural features of both 1a and 1b based on their NMR and X-ray crystal data are discussed, as well as their one-electron reduction forming persistent phosphasilene and phosphagermene anion-radicals.