title: Theoretical investigation of in-plane hydrogen-bonded complexes of ammonia with partially substituted fluorobenzenes.
abstract: Systematic investigation of in-plane hydrogen-bonded complexes of ammonia with partially substituted fluorobenzenes has revealed that fluorobenzene, difluorobenzene, and trifluorobenzene favor formation of cyclic complexes with a C-H...N-H...F-C binding motif. On the other hand, tetrafluorobenzene and pentafluorobenzene favor formation of linear C-H...N hydrogen-bonded complexes. The complete absence of exclusively linear N-H...F hydrogen-bonded complexes for the entire series indicates that C-F bond in fluorobenzenes is a reluctant hydrogen-bond acceptor. However, fluorine does hydrogen bond when cooperatively stabilized with C-H...N hydrogen bonds for the lower fluoro analogues. The propensity of fluorobenzenes to adapt to the C-H...N-H...F-C binding motif decreases with the progressive fluorination of the benzene ring and disappears completely when benzene ring is substituted with five or more fluorine atoms.
authors: Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, India.
authors: Prashant Chandra
authors: PC
authors: Singh
authors: Mohana
authors: M
authors: Ray
authors: G Naresh
authors: GN
authors: Patwari
mesh_terms: D000641:Ammonia / Q000737:chemistry*; D005464:Fluorobenzenes / Q000737:chemistry*; D006860:Hydrogen Bonding; D008956:Models, Chemical; D008958:Models, Molecular; D015394:Molecular Structure
chemical_list: D005464:Fluorobenzenes; D000641:Ammonia