Structural and IR-spectroscopic characterization of pyridinium acesulfamate, a monoclinic twin

BARAN, ENRIQUE J.; PIRO, OSCAR E.; ECHEVERRÍA, GUSTAVO A.; PARAJÓN-COSTA, BEATRIZ S.

ZEITSCHRIFT FUR NATURFORSCHUNG SECTION B - A JOURNAL OF CHEMICAL SCIENCES

VERLAG Z NATURFORSCH

Año: 2018 vol. 0

0932-0776

The crystal structure of pyridinium 6-methyl-1,2,3,-oxathiazine-4(3H)-one, 2.2-dioxide [(C5NH6)(C4H4NO4S)], for short pyH(ace), was determined by X-ray diffraction methods. It crystallizes as a twin in the monoclinic space group P21/c with a = 6.9878(9), b = 7.2211(7), c = 21.740(2) Å, β = 91.67(1)° and Z = 4 molecules per unit cell. The structure was determined employing 1599 reflections with I>2(I) from one of the twin domains and refined employing 2092 reflection from both crystal domains to an agreement R1-factor of 0.0466. Besides electrostatic attraction, intermolecular pyH...O=C(ace) bond stabilizes acesulfamate anion and pyridinium cation into planar discrete units parallel to the (100) crystal plane. The unit forms stacks of alternated ace- and pyH+ ions along the a-axis that favors inter-ring pi-pi interaction. The FTIR spectrum of the compound was recorded and is briefly discussed. Some comparisons with the related pyridinium saccharinate salt are also made.