Structure and reactivity of sodium phenoxide - Following the course of the Kolbe-Schmitt reaction

Article abstract of DOI:10.1002/cber.19971301017

Solvent-free sodium phenoxide (NaOPh) crystallises as a polymer and forms a polymeric chain in the [001] direction. The low coordination of the sodium atoms, as evident in the crystal structure, is confirmed by the easy coordination of oxoligands (σ-donors). Hence, the four-membered ring chain of the solvent-free sodium phenoxide is separated by oxoligands, and forms partial structures as the polymer fragments. Thus, NaOPh crystallises in THF with the formation of an Na₆O₆ core, consisting of two face-fused heterocubes, and in N,N,N′,N′-tetrarnethyl urea (TMU) with the formation of a Na₄O₄ heterocubane. The solvent-free NaOPh-CO₂ complex obtained from the addition of CO₂ to a solution of sodium phenoxide is, when exposed to a temperature of 80 °C, subject to an irreversible phase transition, as demonstrated by FT-IR and DTA studies. The complex formed at 80 °C is, apparently, another intermediate of the Kolbe-Schmitt reaction. WILEY-VCH Verlag GmbH,.