The crystal and molecular structure of magnesium hexa‐antipyrine perchlorate

The structure of magnesium hexa-antipyrine perchlorate, Mg(C 11 H 12 ON 2 ) 6 (ClO 4 ) 2 , has been solved by isomorphous difference-Patterson and trial-and-error methods. The compound crystallizes in the hexagonal system, space group P3, with one formula unit in a unit cell of dimensions a = 14.06, c = 9.76 A. The positional and anistropic thermal parameters of the atoms were refined by the method of least squares to an R value of 0.132 for 1184 observed reflexions. In the structure, the six 3 equivalent antipyrine molecules are coordinated octahedrally to the central Mg 2+ ion through their lone carboxyl oxygen atoms. The pyrazolone and the phenyl rings in the antipyrine group are planar and are inclined to each other by 62.3°. The non-equivalent Cl-O distances in the structure are 1.448 and 1.437 A.