Sodium phenoxide (sodium phenolate) is an organic compound with the formula NaOCH. Sodium phenoxide is a moderately strong base. The sodium salt of phenol, sodium phenoxide, is far more water-soluble. Most commonly, solutions of sodium phenoxide are produced by treating phenol with sodium hydroxide. Adducts of sodium phenoxide are molecular, such as the cubane-type cluster [NaOPh](HMPA). Sodium phenoxide is susceptible to certain types of electrophilic aromatic substitutions. The phenoxide derivative is susceptible to formylation paraformaldehyde to give salicylaldehyde. In general however, electrophiles irreversibly attack the oxygen center in phenoxide. The reactive species is the phenoxide anion (CHO) formed by deprotonation of phenol. Its anion, phenoxide, also known as phenolate, is the conjugate base of phenol.