Supramolecular associates of para-aminobenzoic acid with N- and N,O-heterocyclic molecules

Abstract

A series of novel supramolecular multicomponent complexes of para-aminobenzoic acid (PABA) with N-containing cyclic molecules and aza-crown ethers, (H 2 PPz)

Interaction of hexafluorosilicic acid with sulfa drugs. Bis(sulfathiazolium) hexafluorosilicate: Spectral data and crystal structure

“…We have previously shown that interaction of hexafluorosilicic acid with p-aminobenzoic acid, sulfanilamide and 5-amino-1-benzyl-1,2,3-triazol-4-carbonic acid yielded the corresponding hexafluorosilicates with the aromatic cations formed due to protonation of the terminal amino group [6,12,13]. In a similar way, we expected the formation of the corresponding hexafluorosilicates starting from the sulfa drugs sulfathiazole and sulfalen.…”

“…The crystal structure is stabilized by the network of hydrogen bonding. All fluorine atoms are involved in the hydrogen-bonding system ( 6 ] 2À anion via the imine NH-site ( Fig. 2(a)).…”

“…The reaction mixture was stored under ambient conditions prior to the beginning of crystallization of the reaction product which was obtained with a quantitative yield. The reaction product was a colorless transparent crystals of the composition (C 6 …”

“…This choice is explained by our interest to the co-crystals of sulfa drugs, products of their transformations or other active pharmaceutical ingredients (APIs) [4] possessing H-donor/H-acceptor functions with co-crystal partners of different nature [5,6]. In recent years, this topic has received increased attention [7,8].…”

Supramolecular chemistry of crown ethers

“…The functionalized (oxime, N→O, sulfoxide) pyrimidine derivatives, being coupled with diaza-18-crown-6, revealed different modes of deprotonation (terminal oxime or sulfoxide functionalities or NH of pyrimidine ring) that results in proton-transfer complexes organised in 2D or 3D networks via charge-assisted hydrogen bonds [3]. Anhydrous or hydrated protontransfer complexes were obtained by Aspirin, salicylic, mefenamic or p-aminobenzoic [4] We want to design flexible dynamic frameworks that can create pores to include small guest molecules [1]. These dynamic pores come from a sort of "bistability" of the soft apohost framework, capable to convert from a closed to an open phase in response to guest molecules [2,3].…”