Abstract
The asymmetric unit of the title salt, C17H17F6N2O(+)·C10H8F3O3 (-), comprises two piperidin-1-ium cations and two carboxyl-ate anions. The cations, each having an l-shaped conformation owing to the near orthogonal relationship between the quinolinyl and piperidin-1-ium residues, are pseudo-enanti-omeric. The anions have the same absolute configuration but differ in the relative orientations of the carboxyl-ate, meth-oxy and benzene groups. Arguably, the most prominent difference between the anions occurs about the Cq-Om bond as seen in the Cc-Cq-Om-Cm torsion angles of -176.1 (3) and -67.1 (4)°, respectively (q = quaternary, m = meth-oxy and c = carboxyl-ate). The presence of Oh-H⋯Oc and Np-H⋯Oc hydrogen bonds leads to the formation of a supra-molecular chain along the a axis (h = hy-droxy and p = piperidin-1-ium); weak intra-molecular Np-H⋯Oh hydrogen bonds are also noted. Chains are connected into a three-dimensional architecture by C-H⋯F inter-actions. Based on a literature survey, related mol-ecules/cations adopt a uniform conformation in the solid state based on the letter L.
Highlights
The asymmetric unit of the title salt, C17H17F6N2O+ÁC10H8F3O3À, comprises two piperidin-1-ium cations and two carboxylate anions
The cations, each having an l-shaped conformation owing to the near orthogonal relationship between the quinolinyl and piperidin-1-ium residues, are pseudo-enantiomeric
The presence of Oh—HÁ Á ÁOc and Np—HÁ Á ÁOc hydrogen bonds leads to the formation of a supramolecular chain along the a axis (h = hydroxy and p = piperidin-1-ium); weak intramolecular Np—HÁ Á ÁOh hydrogen bonds are noted
Summary
Biological considerations remain as the primary reason for the study of mefloquine, Scheme 1, and derivatives thereof. Other biological activities have been described for these compounds, namely anti-bacterial (Mao et al, 2007), anti-mycobacterial (Goncalves et al, 2012) and anti-cancer (Rodrigues et al, 2014). It was in this context that the title salt was isolated from the attempted chiral resolution of mefloquine with the carboxylic acid, (+)-PhC(CF3)(OMe)CO2H. There is a noncrystallographic enantiomeric relationship between the cations so the sample is classified as a kryptoracemate Surveys of this phenomenon have appeared in recent times for both organic (Fabian & Brock, 2010) and metal-organic (Bernal & Watkins, 2015) systems. The crystal and molecular structures of the title salt, (I), are described
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
