3,3,4,4-Tetrafluoro-1-[2-(3,3,4,4-tetrafluoropyrrolidin-1-yl)phenyl]pyrrolidine

The asymmetric unit of the title compound, C14H12F8N2, contains one tetrafluoropyrrolidine system and one half-molecule of benzene; the latter, together with a second heterocyclic unit, are completed by symmetry, with a twofold crystallographic axis crossing through both the middle of the bond between the C atoms bearing the heterocyclic rings and the opposite C—C bonds of the whole benzene molecule. The pyrrolidine ring shows an envelope conformation with the apex at the N atom. The dihedral angle between the least-squares plane of this ring and the benzene ring is 36.9 (5)°. There are intramolecular C—H⋯N interactions generating S(6) ring motifs. In the crystal structure, the molecules are linked by C—H⋯F interactions, forming chains parallel to [010].

The asymmetric unit of the title compound, C 14 H 12 F 8 N 2 , contains one tetrafluoropyrrolidine system and one halfmolecule of benzene; the latter, together with a second heterocyclic unit, are completed by symmetry, with a twofold crystallographic axis crossing through both the middle of the bond between the C atoms bearing the heterocyclic rings and the opposite C-C bonds of the whole benzene molecule.The pyrrolidine ring shows an envelope conformation with the apex at the N atom.The dihedral angle between the leastsquares plane of this ring and the benzene ring is 36.9(5) .There are intramolecular C-HÁ Á ÁN interactions generating S(6) ring motifs.In the crystal structure, the molecules are linked by C-HÁ Á ÁF interactions, forming chains parallel to [010].

Comment
It is well known that the introduction of a fluorine atom or a fluoroalkyl group into heterocyclic compounds has a profound influence on their chemical, physical and biological properties (Hagan, 2008).Fluorinated ring play an important role in the pharmaceutical and advanced materials fields (Babudri et al., 2007).Many forms of systemic or topical fluoride have been studied and tested for clinical application (Brambilla, 2001).As a part of our studies in this area, we now report the synthesis and structure of the title compound.
An ORTEP view of the title compound, C 14 H 12 F 8 N 2 , is depicted in Fig. 1.The asymmetric unit contains one tetrafluoropyrrolidin system and a half-molecule of benzene.The whole molecule is generated by rotation around a 2-fold crystallographic axis crossing through, both, the middle of the bond between the carbon atoms bearing the heterocyclic rings (C3 and C3a) and the opposite C1-C1a bond.The pyrrolidine ring shows an envelope conformation with the apex at the N1 atom, the dihedral angle between the least-squares plane of this ring and the benzene moiety is 36.9(5)°.

Figures
Figures

Fig. 1 .
Fig. 1.An ORTEP view of the title compound.Ellipsoids are drawn at the 50% probability level.