Calcium Hydroxide Effect in Degradation of Aqueous Naphthalene: Nucleophilic Substitution of Hydrogen at the C(sp²)–H Bond

Abstract

The degradation of naphthalene in aqueous solutions containing submerged calcium peroxide-based and calcium hydroxide pellets was examined by using UV–vis and IR spectroscopy and mass spectrometry. The observed products are one-ring and fused rings quinoid and aromatic compounds containing OH and C(H)O groups. Their formation is explained in terms of a Ca²⁺ cation–π interaction and a nucleophilic OH^– attack at the aromatic ring ensued by a departure of H^– anion. Such process has not been so far observed in aqueous phase. Its recognition may become a challenge for further studies on applications of alkaline substances in remediation of wastewater and soil contaminated with polycyclic hydrocarbons.

Keywords:

• Calcium hydroxide
• C–H bond
• degradation
• naphthalene
• nucleophilic substitution

Disclosure statement

There are no conflicts of interest to declare.