56140-47-7Relevant articles and documents
Formation constants in C-H hydrogen bonding. 4. Effects of cyano, nitro, and trifluoromethyl substituents in aromatic compounds
Lorand, John P.
, p. 186 - 205 (2015/02/19)
Formation constants ( Keq) have been measured using 1H NMR for H-bond complexes with HMPA in CCl 4of 35 aromatic compounds variously substituted with cyano, nitro, and trifluoromethyl groups; several compounds contained F and Cl. The three strongly polar groups enhance H-bonding significantly, usually in the order NO2 > CN > CF3; all are superior to Cl and F. 1,3,5-Trinitrobenzene fails to H-bond at all; however, TNT, its tert-butyl analog, and trinitro-m-xylene show significant Keq values. Coplanarity of nitro groups with the ring blocks approach of HMPA, probably via intramolecular H-bonds. The buttressing effect is evident in some crowded compounds.