title: Mechanism study of SO2 elimination from sulfonamides by negative electrospray ionization mass spectrometry.
abstract: The elimination of SO2 from deprotonated sulfonamides in the negative ion mode was confirmed by Fourier transform ion cyclotron resonance mass spectrometry (FTICR-MS) experiments. For a set of N-arylbenzenesulfonamides substituted at the para position of the arylamine, the ln([M-H-SO2](-)/[M-H]-) values were correlated with the sigmap(-) substituent constants but, instead of a linear relationship, a bent line was obtained. Analyses of the complex curve led to the identification of two competing routes, which were further investigated by Hartree-Fock theoretical calculations. Furthermore, collision-induced dissociation (CID) of deprotonated N-alkylbenzenesulfonamides containing the -CHCHNHSO2- structure yielded a [M-H-66](-) product ion This characteristic ion could help to distinguish the side-chain isomers.
authors.affiliation: Department of Chemistry, Zhejiang University, Hangzhou 310027, China.
authors.forename: Nan
authors.initials: N
authors.lastname: Hu
authors.forename: Pengyuan
authors.initials: P
authors.lastname: Liu
authors.forename: Kezhi
authors.initials: K
authors.lastname: Jiang
authors.forename: Yuping
authors.initials: Y
authors.lastname: Zhou
authors.forename: Yuanjiang
authors.initials: Y
authors.lastname: Pan
mesh_terms: D008956:Models, Chemical; D021241:Spectrometry, Mass, Electrospray Ionization / Q000295:instrumentation / Q000379:methods*; D013329:Structure-Activity Relationship; D013449:Sulfonamides / Q000737:chemistry*; D013458:Sulfur Dioxide / Q000737:chemistry*; D013816:Thermodynamics
chemical_list: D013449:Sulfonamides; D013458:Sulfur Dioxide