HYDROGEN-BOND STUDIES .36. CRYSTAL STRUCTURE OF 1-1 ADDITION COMPOUND OF ACETIC ACID WITH FLUOROSULFURIC ACID

The crystal structure of CH3COOH.HSO3F has been determined from three-dimensional single-crystal X-ray data obtained at -57°. The crystals are monoclinic, space group P21/c, with four formula units in a cell of dimensions a = 7.732 (9) Å, b = 8.093 (5) Å, c = 9.982 (2) Å, and β = 108.06 (9)°. The acetic acid exists in the form of CH3C(OH)2+ ions (acetate acidium ions), in which one proton is attached to each of the two oxygen atoms. The CH3C(OH)2+ and SO3F- ions are hydrogen bonded to each other forming infinite chains parallel to the b axis. The O-H…-O bond lengths are 2.568 (6) and 2.583 (6) Å. The S-O distances within the fluorosulfate group are 1.418 (5), 1.429 (4), and 1.432 (4) Å; the S-F distance is 1.561 (4) Å. In the CH3C(OH)2+ ion the C-C distance is 1.469 (8) Å; the two C-O distances are 1.261 (7) and 1.273 (7) Å. The above distances are not corrected for thermal motion. © 1969, American Chemical Society. All rights reserved.