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We unified the number-of-layer dependence of the A1g and the E12g phonon frequencies of the layered MX2 (M = Mo and W; X = S and Se) semiconductors with derivative of quantitative information on the bond relaxation dynamics and clarification of their physical origins. Theoretical reproduction of observations confirms that atomic undercoordination stems the unusual behavior of phonons of the MX2. The difference in electronegativity and ionic radius between the constituent elements resolves the bond nature index m and the relaxation extents of phonon frequencies. It is also clarified that the dimer interaction dictates the blue shift of the E12g phonon but the collective interaction of an atom with its z-neighbors governs the red shift of the A1g phonon dynamics as the number-of-layer reduces. Copyright © 2017 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Although the alcohol-water mixtures are ubiquitously important to beverage and pharmacy industries, it remains yet puzzling how the alcohols interact with watermolecules and how the alcoholmolecules functionalize the hydrogen bond network of liquid water and body fluid. We show spectrometrically that alcohol hydration softens both the H-O bond and the O:H nonbond through hydrogen bond cooperative relaxation and associated charge polarization. Observations suggested that each of the dangling hydroxide group :Ö:H- (interacts with :Ö or -H+) and the dangling methyl group C-H+ (with -H+ or :Ö) is equally capable of interacting with H2O molecules in the form of Ö:↔:Ö point compressor, H+↔H+ point breaker, and O:H-O hydrogen bond at the alcohol-water interface without charge sharing or new bond formation. The alcohol-water O:H-O formation enables the solubility and hydrophilicity of the alcohol; the H+↔H+ breaker embrittles the hydration network; the Ö:↔:Ö compression shortens the O:H nonbond and lengthens the H-O bond. H-O softening is associated with heat emission and depression of solution melting temperature; the O:H nonbond softening (due to polarization) lowers the critical temperatures for freezing. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]