Hydrogen bond in liquid water

VIBRATIONAL LINE SHAPES, SPECTRAL DIFFUSION, AND HYDROGEN BONDING IN LIQUID WATER... 

Hydrogen bonding in liquid water was discussed. The significance of the dipolar character of the water molecule was pointed out and its relation to the large value of the permittivity of the bulk... 

Luck, W. A. P. Hydrogen Bonds in Liquid Water, in Recent Progress in Hydrogen Bonds, Chapt. 28 (ed. P. Schuster, G. Zundel, C. Sandorffy). Amsterdam North Holland Publ. 

When a crystalline solid melts to a liquid, the regularity of the lattice is lost, but some local order may be retained. For example, in crystalline ice, each O atom is surrounded by four other O atoms linked by hydrogen bonds. In liquid water, the hydrogen bond network is partially retained, at least instantaneously, but long-range order is lost as the individual molecules are free to move about. Liquids with weaker intermolecular interactions are even more chaotic. 

At l(atm), Hr v should be negligible relative to AHlv. Then HRl —AHlv. Because the normal boiling point is a representative T for typical liquid behavior, and because HR reflects intermolecular forces, A Hlv has the stated feature. s.Hlv( CO) is much larger than A/Z ICIE) because of the strong hydrogen bonding in liquid water. 

Hydrogen Bonding in Liquid Water and Aqueous Solutions. 

Xenides D, Randolf BR et al (2006) Hydrogen bonding in liquid water an ab initio QM/MM MD simulation study. J Mol Liquids 123 61... 

Gale GM, Gallot G, Hache F, Lascoux N, Bratos S, Leicknam JCL, Femtosecond dynamics of hydrogen bonds in liquid water a real time study. Phys Rev Lett 1999 82 1068-1071. 

The hydrogen bonds in liquid water have an average lifetime of less than 10"10 second as measured by dielectric relaxation times (4). But the hydrogen bonds between water and a polymer could exist for longer than 10"7 seconds. Such a structure would appear permanent at the frequencies used in the ultrasonic impedometer (107 cycles/sec. range), and should demonstrate a measurable shear stiffness at these frequencies. 

In liquid hydrazine, hydrogen bonding occurs between the hydrazine molecules similar to the hydrogen bonding in liquid water. In solid hydrazine, the hydrogen bonds have NH-N distances between 319 and 367 pm. In hydrazine hydrate, each hydrazine molecule is linked via six hydrogen bonds to surrounding water molecules so that the hydrazine molecules are separated from each other by water molecules. Some physical properties of hydrazine and hydrazine hydrate are shown in Table 16. 

Blumberg RL, Stanley HE, Geiger A, Mausbach P. Connectivity of hydrogen bonds in liquid water. J. Chem. Phys. 1984 80 5230-5241. 

Silverstein KAT, Haymet ADJ, Dill KA. The strength of hydrogen bonds in liquid water and around nonpolar solutes. J. Am. Chem. Soc. 2000 122 8037-8041. 

C. J. Montrose, J. A. Bucaro, J. Marshall-Coakley, and T, A. Litovitz. Depolarized Rayleigh scattering and hydrogen bonding in liquid water. 5. Chem. Phys., 60 5025-5029 (1974). 

Why is water so unique and why are its properties so different from those of the normal liquids These questions have been asked by numerous researchers, and so far, there are no absolute answers. However, there is one point on which almost all researchers agree the network of hydrogen bonds in liquid water and ice (a water molecule can form up to four H-bonds) is the key to the understanding of this mystery . Therefore, the main emphasis of Chapter 6 is on the H-bond network in water and dilute aqueous solutions. 

The heat of water vaporization is much higher than that of many other liquids. As is the case with melting ice, a large amount of thermal energy is required for breaking hydrogen bonds in liquid water, to permit water molecules to dissociate from one another and to enter the gas phase. Perspiration is an effective mechanism of decreasing body temperature because the evaporation of water absorbs so much heat. 

Falk and Ford concluded that hydrogen bonds in liquid water have a broad smooth single-peaked distribution of strengths which gradually shifts with temperature. At one end of this distribution the hydrogen bond strengths are comparable to... 

In the preceding section, we discussed the equilibrium aspects of the percolating network of extended hydrogen-bonding in liquid water. We now discuss the dynamics of the rearrangement of this network. 

Woessner DE (1964) Molecular reorientation in liquids. Deuteron quadrupole relaxation in liquid deuterium oxide and perdeuterobenzene. J Chem Phys 40 2341-2348 Xenides D, Randolf BR, Rode BM (2006) Hydrogen bonding in liquid water an ab initio QM/MM MD simulation study. J Mol Liquids 123 61-67 Yalkowsky SH, Baneijee S (1992) Aqueous solubility. Dekker, New York Yalkowsky SH, Valvani SC (1980) Solubility and partitioning I solubility of nonelectrolytes in water. J Pharm Sci 69 912-922... 

Salt in water Requires breaking strong bonds between ions, and disrupting hydrogen bonding in liquid water, but ions often become strongly hydrated as polar water molecules are attracted to the ions. Some, but not all, ionic solids are very soluble in water. 

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