Variety of Intermolecular Reactions via Active Species in Gas Hydrates

Abstract

Recent progress in observations of radiation-induced radicals in gas hydrates was reviewed. Two different types of intermolecular hydrogen transfer reactions were observed. One is hydrogen-picking reaction where alkyl radicals withdraw hydrogen of alkane guest molecules in the adjacent cages of alkane hydrates. The other is hydrogen-hopping reaction where carboxyl (HOCO) radicals transfer excess hydrogen to CO₂ molecules in the adjacent cages of CO₂ hydrate. In the CO₂+methane mixed gas hydrates, the yield of radiation-induced radicals increases by reducing the inverse reactions of radical formation. The variety of intermolecular reactions in gas hydrates will attract us not only in physical chemistry but also in application area using new reaction field.