Experimental and computational analysis of supramolecular motifs involving Csp2(aromatic)–F and CF3 groups in organic solids. (8th April 2016)

• Record Type: Journal Article
• Authors: Panini, Piyush; Gonnade, Rajesh G.; Chopra, Deepak
• Is Part Of: New journal of chemistry. Volume 40:Number 6(2016:Jun.)
• Page Start: 4981
• Page End: 5001
• Publication Date: 2016-04-08
• Subjects: Chemistry -- Periodicals; Chimie -- Périodiques; 540
• DOI: 10.1039/c5nj03211c
• Languages: English
• ISSNs: 1144-0546

Abstract

Abstract : Structural motif by Csp 2 –F and CF3 group have been identified and investigated by the PIXEL method and QTAIM approach. Abstract : A detailed experimental (SCXRD) and theoretical (PIXEL and QTAIM) investigation of the evolution of different supramolecular motifs formed via the presence of both C(sp 2 )/(sp 3 )–F groups in the crystal packing has been performed in a series of newly synthesized substituted benzanilides (containing "both" the fluorine and the trifluoromethyl group in the same molecule) along with previously reported similarly related crystal structures [ CrystEngComm, 2008, 10, 54–67; CrystEngComm, 2012, 14, 1972–1989, CrystEngComm, 2013, 15, 3711–3733]. It was observed that the highest stabilized molecular motifs primarily consist of C(sp 2 )–H⋯F–C(sp 2 ) H-bonds in preference to C(sp 2 )–H⋯F–C(sp 3 ) H-bonds in the crystal. The motifs involving C(sp 2 )–H⋯F–C(sp 2 )/(sp 3 ) H bonds were observed to be present over the entire distance range between 2.2 and 2.7 Å, albeit the difference in energies of stabilization involving fluorine atoms attached to sp 2 and sp 3 carbon is not significant in molecular crystals. From QTAIM analysis, the C(sp 2 )/(sp 3 )–F⋯F–C(sp 2 )/(sp 3 ) interactions were observed to be a closed shell in nature and provide local stabilization, indicating the formation of bonds, similar to weak hydrogen bonds observed in crystals.