The crystal structures of eleven ionic compounds containing the substituted guanidinium cations [C(NH2)2(NHR)]⁺ (R = Me, Et) or [C(NH2)2(NMe2)]⁺ and the sulfonate anions [RSO3]^â (R = 1-naphthalene, 2-naphthalene, d-(+)-10-camphor, Me, Ph) have been determined in order to investigate the effects of removing Nâ H groups on the symmetrical guanidinium sulfonate hydrogen-bonded layer structure. Analysis of the supramolecular structures of these compounds, together with those of previously reported compounds in the same series, has shown that the monoalkylguanidinium sulfonates generally respond to the loss of a hydrogen bond donor by forming one of two hydrogen bonds patternsâ shifted ribbon sheets or adapted sheetsâ and the way in which these sheets are arranged in the gross structure is, in most cases, similar to that of the related unsubstituted guanidinium sulfonate. In contrast, dimethylguanidinium sulfonates form structures based on cationâ ¯anion pairs that are inter-connected into ribbons or sheets.