“…1), which is yet another zwitterionic compound. The structure of (I) is a rare example of an organic thiosulfate, these being limited to one aromatic (Boese et al, 1999) and six aliphatic examples (Cruz et al, 1995;Foust & Janickis, 1980;Keefe & Stewart, 1972;Okaya, 1966;Steudel et al, 1993;Zhang et al, 1985). In all of these, an ammonium (ÀNH 3 or >NH 2 ) group interacts with the thiosulfate group through hydrogen bonds, and the SÐO distances in the thiosulfate unit are similar to one another, in agreement with the delocalized nature of this group; for example, in CH 3 NH 2 CH(CH 3 )CH(C 6 H 5 )S 2 O 3 , the three SÐO distances are essentially identical [1.445 (2), 1.448 (2) and 1.456 (2) A Ê ; Cruz et al, 1995].…”