ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Reactions of perchlorates with antipyrine

S. Šimko, E. Polášek, and J. Čelechovský

Department of Physical Chemistry, Faculty of Pharmacy, Komenský University, Bratislava

Abstract: By gradually acidifying an antipyrine (L) soln. in the presence of perchlorates, white, needlelike crystals of the salt HL₂ClO₄ are formed which are slightly sol. in H2O and very sol. in acid and alk. media. The soly. can be expressed by the equation KS = aClO4-×aH(L)2+, which equals 1.08 × 10^-6, under the condition that K₂ = [H] [L]2/[H(L)2+] = 0.634. It forms the H(L)+ ion, which if dissolved in the acid medium, the concn. is given by the following equil. const.: K1 = [H] [L]/[HL]+ = 4.18 × 10^-2. The stability and soly. of this salt increase with temp. up to 70°, so that it can be thoroughly purified and applied as an anal. standard for elementary anal.

Full paper in Portable Document Format: 219a723.pdf (in Czech)

Chemical Papers 21 (9) 723–728 (1967)