Theoretical investigation of in-plane hydrogen-bonded complexes of ammonia with partially substituted fluorobenzenes.
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.
Singh
Prashant Chandra
PC
Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400 076, India.
Ray
Mohana
M
Patwari
G Naresh
GN
D000641:Ammonia / Q000737:chemistry*; D005464:Fluorobenzenes / Q000737:chemistry*; D006860:Hydrogen Bonding; D008956:Models, Chemical; D008958:Models, Molecular; D015394:Molecular Structure
D005464:Fluorobenzenes; D000641:Ammonia