Novel aryl oxalate esters for peroxyoxalate chemiluminescence reactions

Abstract

Six oxalate esters of 2-nitro-4-alkoxycarbonylphenol and 2-alkoxycarbonyl-4-nitrophenol were synthesised for use in the peroxyoxalate chemiluminescence reactions that take place via several steps with 4-hydroxy-3-nitrobenzoic acid and 5-nitrosalicylic acid as starting materials, respectively. The addition of ethylene glycol to the alkoxy moiety enhanced the solubility in solvents such as acetone, acetonitrile and ethyl acetate. When reacted with hydrogen peroxide in the presence of a fluorescent compound, perylene, they gave similar chemiluminescence reaction curves to those of DNPO [bis(2,4-dinitrophenyl) oxalate] and TCPO [bis(2,4,6-trichlorophenyl) oxalate]. Among them, bis[4-nitro-2-(3,6,9-trioxadecyloxycarbonyl)phenyl] oxalate was found to be the best for the high-sensitivity detection of both hydrogen peroxide and fluorescent compounds using the peroxyoxalate chemiluminescence reaction because of its extreme solubility in solvents such as acetone (767 mM) and acetonitrile (1010 mM).