Aminosulfonic acids. Part 1. Crystal structures of N-methylaminomethanesulfonic acid, MeNHCH2SO3H, and disodium N-methyliminobis(methanesulfonate) dihydrate, MeN(CH2SO3Na)2•2H2O

Abstract

The crystal structure of N-methylaminomethanesulfonic acid (P212121, a = 5.455(1) Å, b = 7.791(1) Å, c = 11.925(2) Å, Z = 4) consists of +MeNH2CH2SO3− zwitterions hydrogen-bonded to form infinite chains about screw axes parallel to a. In the structure of MeN(CH2SO3Na)2•2H2O (Pbcn, a = 10.469(1) Å, b = 6.039(3) Å, c = 17.549(3) Å, Z = 4), layers of MeN(CH2SO3−)2 anions alternate with layers of Na+ ions parallel to (001). The anions are linked by [Formula: see text] bonds between the water molecules and the O(2) atoms of the sulfonate groups. Because of the twofold orientational disorder of the N—CH3 groups the space group Pbcn is only statistical.The S—C, C—N, and S—O bond lengths in solid aminosulfonic acids and their salts are discussed with a view to detecting the existence of effects due to deprotonation of the amino group and to hydrogen bonding.