4-Ammonio-5-methoxy-2-methylbenzenesulfonate

Alan R Kennedy,Lygia Silva De Moraes

doi:10.1107/s2414314616017788

Abstract

The title compound, C8H11NO4S, crystallizes as a zwitterion, with the negatively charged benzenesulfonate group and the positively charged NH3+group in mutuallyparapositions. All the non-H atoms, except for one O atom of the sulfonate group, lie on a crystallographic mirror plane (Z′ = 1/2). In the crystal, the hydrogen-bonding structure is two-dimensional, propagating in thec-axis direction through a bifurcated hydrogen bond between the NH3+and the SO3−groups, and in theb-axis direction through anR22(16) ring motif involving the same functional groups. This latter hydrogen bonding is supported by offset π–π interactions [intercentroid distance = 3.8114 (4) Å].

Highlights

The title compound, C8H11NO4S, crystallizes as a zwitterion, with the negatively charged benzenesulfonate group and the positively charged NH3+ group in mutually para positions
The hydrogen-bonding structure is two-dimensional, propagating in the c-axis direction through a bifurcated hydrogen bond between the NH3+ and the SO3À groups, and in the b-axis direction through an R22(16) ring motif involving the same functional groups. This latter hydrogen bonding is supported by offset – interactions [intercentroid distance = 3.8114 (4) A ]
The body of the molecule lies on the crystallographic mirror plane (Z0 = 12) with only atom O3 of the sulfonate group and H atoms of the methyl and NH3+ groups out of plane

Summary

Structure description

Amino-benzenesulfonic acids are used extensively in the preparation of azo dyes and pigments (Christie, 2015). Their crystal structures tend to be zwitterionic with a negatively charged sulfonate and protonation of the amine to give NH3+ (Smith et al, 2006; Butcher & Deschamps, 2006; Sledzet al., 2010). Hydrogen bonding involves the NH3+ group as an H-donor and the O atoms of the SO3À group as the acceptors (Table 1).

DÁ Á ÁA

Data collection Diffractometer Absorption correction

Synthesis and crystallization

Crystal data

Oxford Diffraction Xcalibur E diffractometer

Special details