Hydrogen bonds, infrared

TABLE 1. Hydrogen Bonding Infrared Frequency Shifts for Various Compounds"... 

Sammes, M.P. and Harlow, R.L. (1976) Intramolecular hydrogen bonds involving polar carbon hydrogen bonds infrared and H nuclear magnetic resonance spectra of some cyano-methyl and benzyl sulphones, J. Chem. Soc. Perkin Trans. H, 1130 1135. 

ZuNDEL, G., Proton polarizability of hydrogen bonds infrared methods, relevance to electrochemical and biological systems. Methods Enzymol., 1986, 127, 439-455. 

The exit gas from the generator ice trap is dissolved directly in water. The hydrogen-ion concentration of the resulting solution is determined by titration with standard base, and the iodide-ion concentration by the precipitation of silver iodide. Only traces of tetrahydronaphthalene are detected by the very slight carbon-hydrogen bond-infrared absorption in the samples of the anhydrous gas prepared by this procedure. 

Lindemann R, Zundel G (1977) Polarizability, proton transfer and symmetry of energy surfaces of carboxylic acid W-base hydrogen bonds—infrared investigations. J Chem Soc Faraday Trans 2(73) 788-803... 

Analytical Chemistry Collision-Induced Spectroscopy Hydrogen Bond Infrared Spectroscopy Interstellar Matter Ion Kinetics and Energetics Microwave Communications Millimeter Astronomy Quantum Chemistry Time... 

The low melting point of hydrazine hydrate seen in Table 1.2 is consistent with a solid crystal structure that is somewhat different from that of anhydrous hydrazine (Figure 1.2) [4,5]. The low melting point of the hydrate indicates that its crystal is held together by relatively weak chemical forces like hydrogen bonds. Infrared, Raman, microwave. Nuclear Magnetic Resonance (NMR), photoelectron spectra, and X-ray diffraction have been used to elucidate the structure of the crystal and bonding in these molecules. Both hydrazine and hydrazine hydrate... 

Provencal R A ef a/1999 Infrared cavity ringdown spectroscopy of methanol clusters single donor hydrogen bonding J. Chem. Phys. 110 4258-67... 

Ayotte P, Bailey C G, Weddle G FI and Johnson M A 1998 Vibrational spectroscopy of small Br (Fl20) and I Fl20) clusters infrared characterization of the ionic hydrogen bond J. Phys. Chem. A 102 3067-71... 

The infrared spectra of A-4-thiazoline-2-ones are characterized by a strong absorption around 1650 cm (55, 86, 103, 107. 870). For the N-H derivatives, the whole range 2700 to 3200 cm is covered by a strong absorption related to the dimeric and oligomeric states of the hydrogen-bonded structures (85, 86). 

Frohlich, H. Using Infrared Spectroscopy Measurements to Study Intermolecular Hydrogen Bonding, /. Chem. Educ. 1993, 70, A3-A6. 

Poly(vinyl acetate). The dielectric and mechanical spectra of hybrids produced by mixing a poly(vinyl acetate)—THE solution with TEOS, followed by the addition of HCl have been investigated (45). Mixtures were made which were beheved to be 0, 5, 10, 15, and 20 wt % Si02, respectively. These composites were transparent and Eourier transform infrared spectroscopy (ftir) revealed hydrogen bonding between the siUcate network and carbonyl units of the poly(vinyl acetate) (PVAc). No shift in the T of the composites from that of the pure PVAc was observed. Similarly, the activation... 

Color from Vibrations and Rotations. Vibrational excitation states occur in H2O molecules in water. The three fundamental frequencies occur in the infrared at more than 2500 nm, but combinations and overtones of these extend with very weak intensities just into the red end of the visible and cause the blue color of water and of ice when viewed in bulk (any green component present derives from algae, etc). This phenomenon is normally seen only in H2O, where the lightest atom H and very strong hydrogen bonding combine to move the fundamental vibrations closer to the visible than in any other material. 

In dimers composed of equal molecules the dimer components can replace each other through tunneling. This effect has been discovered by Dyke et al. [1972] as interconversion splitting of rotational levels of (HF)2 in molecular beam electric resonance spectra. This dimer has been studied in many papers by microwave and far infrared tunable difference-frequency laser spectroscopy (see review papers by Truhlar [1990] and by Quack and Suhm [1991]). The dimer consists of two inequivalent HE molecules, the H atom of one of them participating in the hydrogen bond between the fluorine atoms (fig. 60). PES is a function of six variables indicated in this figure. 

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