HOMOCONJUGATED RSIBLE-ARROW-N-CENTER-DOT-CENTER-DOT-CENTER-DOT-HN HYDROGEN-BONDS IR CONTINUUM AND PROTON POLARIZABILITY AS A FUNCTION OF THE PK(A) OF THE NH ACIDS

We synthesized systems with NH ... N(-)reversible arrow(-)N ... HN hyd rogen bonds by the reaction of five NH acids with the phosphazene (P2E t) base and studied them by FT-IR spectroscopy. The intensity of the o bserved IR continua caused by the NH ... N(-)reversible arrow(-)N ... HN hydrogen bonds is comparable with all systems. Thus, the proton pol arizabilities and the proton potentials are independent of the pK(a) o f the NH acids. The band structure observed in the region 3000-1700 cm (-1) is caused by Fermi resonance of nu(NH) and the overtone of the ri ng breathing vibration. (C) 1997 Published by Elsevier Science B.V.