The Crystal Structure of Sulfamic Acid

Abstract

X-Ray studies show that sulfamic acid crystallizes in the orthorhombic system. The unit cell, comprised of eight molecules, has ao = 8.100 Å., b0 = 8.049 Å., and C0 = 9.228 Å., all ±0.002 Å. All atoms are in general positions of the space group [formula omitted]−Pbcs. Analysis of diffraction intensity data by means of Patterson-Harker projections and Fourier refinements established the parameters. Hydrogen parameters were deduced to fit this structure. Interatomic distances within the molecule are: sulfur-nitrogen, 1.73 Å.; sulfur-oxygen (1), 1.49 Å.; sulfur-oxygen (2), 1.47 Å.; sulfur-oxygen (3), 1.48 Å. (all ±0.05 Å.). Bonding conditions are discussed resulting in the conclusion that the acid crystallizes as zwitterion molecules (NH3+SO3−) of a distorted tetrahedral form. Extensive hydrogen bonding of the type N-H···O is shown to exist in the structure with each NH3+ group entering into five bridging systems. The hydrogen bond distances vary from 2.82-3.07 Å. © 1951, American Chemical Society. All rights reserved.