Evidence for Bonded Hydrogen

Ion beam profiling techniques have been used to determine the total content and concentration versus depth of hydrogen in a-Si H (Lanford et al., 1976 Brodsky et al., 1977b Ziegler et al., 1978 Milleville et al., 1979). An a-Si H sample is bombarded with 15N ions, which can undergo a resonant reaction. 

Vibrational spectroscopy is a very important tool in characterizing the content and local bonding environments of hydrogen in a-Si H (Brodsky et al., 1977a Knights et al., 1978). The infrared absorption 

The Raman spectra of a-Si H show complementary hydrogen vibrational bands in those spectral regions that are free of contributions from 

The nature of the clustered phase is not well understood. One possible interpretation is that a cluster is composed of a relaxed divacancy whose inner surface is dressed with hydrogens however there is no direct NMR data which supports this identification (Reimer and Petrich, 1988). Alternatively, it has been suggested that the broad component of the NMR spectrum arises from hydrogen atoms lined up alone microtubular structural defects (Chenevas-Paule and Bourret, 1983). 

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A hydrate CO2.8H2O can be crystallized from aqueous solutions at 0° and p C02) 45 atm. There is also evidence for a hydrogen-bonded sesquicarbonate ion, H3C20s this was originally suggested to have the sandwich... 

Pant and Levinger have measured the solvation dynamics of water at the surface of semiconductor nanoparticles [48,49]. In this work, nanoparticulate Zr02 was used as a model for the Ti02 used in dye-sensitized solar photochemical cells. Here, the solvation dynamics for H2O and D2O at the nanoparticle surface are as fast or faster than bulk water motion. This is interpreted as evidence for reduced hydrogen bonding at the particle interface. 

There has been one recent report of a paramagnetic hydrogen state, with indirect evidence that it would be associated with the bond center. ESR experiments by Gorelkinskii and Nevinnyi (1987) and by Gordeev et al. (1988) showed the existence of a paramagnetic state due to H in Si, called the AA9 center. They also showed that the characteristics of AA9 are similar to those of Mu. Since Mu is now known to be associated with the bond center (a fact not appreciated by the Russian group), this provides indirect evidence for bond-centered hydrogen. 

Additional evidence for the hydrogen bonding mechanism is provided by Douglas and Dietz 20> who observed that Jl3 for chloroform increases with... 

DR. NORTON An excellent attempt to observe such hydrogen bonding was made recently by Fachinetti, et al. [Calderazzo, F. Fachinetti, G. Marchetti, F. Zanazzi, P. F. J. Chem. Soc., Chem. Commun. 1981, 181]. They took hydridocobalttetracarbonyl and triethylamine, and crystallized out a species which one can only describe as the tetracarbonylcobaltate of protonated triethylamine. They proposed some type of interaction between the hydrogen and a face of the cobalt tetrahedral complex, but it was clear that the interaction was almost entirely with nitrogens. The conclusion I would draw is that the complex appears to proceed directly to full protonation of the amine without any observable evidence for a hydrogen bonded intermediate. 

The infrared spectra of carboxylic acids provide clear evidence for the hydrogen bonding discussed in the preceding section. This is illustrated in Figure 18-2, which shows the spectrum of ethanoic acid in carbon tetrachloride solution, together with those of ethanol and ethanal for comparison. 

Determinant by the Lectin IV of Griffonia simplicifolia and by a Monoclonal Anti-Lewis b Antibody. Evidence for Intramolecular Hydrogen Bonding, R. U. Lemieux, R. Cromer, and U. Spohr, Can. J. Chem., 66 (1988) 3083-3098. 

C. H. DePuy and P. R. Story, Gas chromatographic evidence for intramolecular hydrogen bonding with double bonds, Tetrahedron Lett. 1 (1959), 20. 

Acid-base properties of ( H-benzimidazol-2-yl-methyl)phosphonate (Bimp ) (502) were investigated. Evidence for intramolecular hydrogen bond formation in aqueous solution between (N-l)H and the phosphonate group was presented (Figure 91) ... 

Michel, D., Witschard, M. and Schlosser, M. (1997) No evidence for intramolecular hydrogen bonds in a-fluorocarboxamides. Liebigs Ann., 517-519. 

B.S. Hudson, D.A. Braden, D.G. Allis, T. Jenkins, S. Baronov, C. Middleton, R. Withnall C.M. Brown (2004). J. Phys. Chem. A, 108, 7356-7363. The crystalline enol of 1,3-cyclohexanedione and its complex with benzene vibrational spectra, simulation of structure and dynamics and evidence for cooperative hydrogen bonding. 

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