A force-constant approach to O–H interactions in the light of the chained interactions conjecture

Abstract

The chain interaction conjecture (ChIC) establishes that as any chemical bond is stretched, it must undergo a concatenated sequence of pair interactions of decreasing strength at specific distances defined by mechanical (spinodal) and energetic (rigid sphere) instabilities in the potential energy. A comprehensive analysis of ChIC is provided by studying the effect of temperature on OH interactions in water for temperatures between 240 and 450 K. The effects of temperature on the OH bond are rationalized using classical potential energy models and force constants, and OH stretching frequencies are used as a check on the goodness of the approximation. We demonstrate that the characteristic distances of the instabilities for the three interactions considered (covalent, hydrogen bond, and dispersive) correlate remarkably well with characteristic OH distances found in experimental, simulation, and theoretical studies.