title: 5-Hydr-oxy-1-methyl-3,4-dihydro-2H-pyrrolium hydrogensulfate.
abstract: The title compound, C(5)H(10)NO(+)·HSO(4) (-), has been synthesized by reaction of 1-methyl-pyrrolidin-2-one with H(2)SO(4) in a 1:1 molar ratio. The substituted pyrrolium ring adopts an envelope conformation. The hydrogensulfate anions form infinite helical chains parallel to the a axis via strong O-H⋯O hydrogen bonds. The pyrrolium cations are pendant from the chains. These cations are the hydrogen donors in the strong O-H⋯O hydrogen bonds to the hydrogensulfates. In addition, there are weak C-H⋯O hydrogen bonds in the structure.
authors.affiliation: Faculty of Light Industrial and Chemical Engineering, Guangdong University of Technology, Guangzhou 510090, People's Republic of China.
authors.forename: Yan-Xiong
authors.initials: YX
authors.lastname: Fang
authors.forename: Hua-Rong
authors.initials: HR
authors.lastname: Huang
authors.forename: Zhi-Yun
authors.initials: ZY
authors.lastname: Du
authors.forename: Bao-Hua
authors.initials: BH
authors.lastname: Huang
authors.forename: Kun
authors.initials: K
authors.lastname: Zhang