Interlayer Water Molecules in the Vanadium Pentoxide Hydrate, V2O5·nH2O. 6. Rigidity of Crystal Structure against Water Adsorption and Anisotropy of Electrical Conductivity

Langmuir ◽  
1996 ◽  
Vol 12 (4) ◽  
pp. 1078-1083 ◽  
Author(s):  
Shigeharu Kittaka ◽  
Hiroya Hamaguchi ◽  
Takeshi Shinno ◽  
Tohru Takenaka
Keyword(s):  
Crystal Structure ◽  
Electrical Conductivity ◽  
Vanadium Pentoxide ◽  
Water Adsorption ◽  
Water Molecules ◽  
Interlayer Water

Interlayer water molecules of vanadium pentoxide hydrate, V2O5nH2O

1992 ◽  
Vol 154 (1) ◽  
pp. 216-224 ◽  
Author(s):  
Shigeharu Kittaka ◽  
Tomoyuki Suetsugi ◽  
Rika Kuroki ◽  
Mahiko Nagao
Keyword(s):  
Vanadium Pentoxide ◽  
Water Molecules ◽  
Interlayer Water

Interlayer Water Molecules in Vanadium Pentoxide Hydrate, V2O5·nH2O. 7. Quasi-elastic Neutron Scattering Study

Langmuir ◽  
2000 ◽  
Vol 16 (26) ◽  
pp. 10559-10563 ◽  
Author(s):  
Shuichi Takahara ◽  
Shigeharu Kittaka ◽  
Yasushige Kuroda ◽  
Toshio Yamaguchi ◽  
Hiroyuki Fujii ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Vanadium Pentoxide ◽  
Water Molecules ◽  
Interlayer Water ◽  
Elastic Neutron ◽  
Scattering Study ◽  
Elastic Neutron Scattering ◽  
Neutron Scattering Study

Ionic Properties of Vanadium Pentoxide Gels

1988 ◽  
Vol 121 ◽  
Author(s):  
J. Livage ◽  
P. Barboux ◽  
J. C. Badot ◽  
N. Baffier
Keyword(s):  
Vanadium Pentoxide ◽  
Water Adsorption ◽  
Mixed Valence ◽  
Adsorbed Water ◽  
Water Molecules ◽  
Proton Diffusion ◽  
Hydrous Oxides ◽  
Solution Interface ◽  
Ionic Devices ◽  
Acid Aqueous Medium

ABSTRACTVanadium pentoxide gels V2O5·nH2O are actually hydrous oxides. Water adsorption and dissociation occurs at the surface of the oxide leading to negatively charged oxide particles surrounded by an acid aqueous medium. Ionic conductivity is observed, arising from proton diffusion through the water molecules. This process mainly depends on the nature of adsorbed water molecules. Proton conductivity is strongly related to the water adsorption isotherm.Ion exchange readily occurs at the oxide-solution interface when the gel is dipped into an aqueous solution of a metal chloride. New vanadium bronzes have been obtained upon heating such gels around 300° C. They exhibit interesting properties as reversible cathodes.Electrochemical insertion of Li* into the gel phase is quite easy. This is due to the very open structure of the gel and the mixed valence behavior of the vanadium oxide.Transition metal oxide gels could then be used as thin films or pressed pellets for making micro-ionic devices.

Interlayer Water Molecules in Vanadium Pentoxide Hydrate. 8. Dynamic Properties by Quasi-Elastic Neutron Scattering

Langmuir ◽  
2005 ◽  
Vol 21 (4) ◽  
pp. 1389-1397 ◽  
Author(s):  
Shigeharu Kittaka ◽  
Shuichi Takahara ◽  
Toshio Yamaguchi ◽  
Marie-Claire Bellissent Funel
Keyword(s):  
Neutron Scattering ◽  
Vanadium Pentoxide ◽  
Dynamic Properties ◽  
Water Molecules ◽  
Interlayer Water ◽  
Elastic Neutron ◽  
Elastic Neutron Scattering

Restricted Rotational Motion of InterlayerWaterMolecules in Vanadium Pentoxide Hydrate, V2O5·n D2O, as Studied by Deuterium NMR

2002 ◽  
Vol 57 (6-7) ◽  
pp. 419-424 ◽  
Author(s):  
Sadamu Takeda ◽  
Yuko Gotoh ◽  
Goro Maruta ◽  
Shuichi Takahara ◽  
Shigeharu Kittaka
Keyword(s):  
Double Layer ◽  
Vanadium Pentoxide ◽  
Rotational Motion ◽  
Interlayer Space ◽  
Layer Structure ◽  
Bond Distance ◽  
Adsorbed Water ◽  
Deuterium Nmr ◽  
Water Molecules ◽  
Layer Structures

The rotational behavior of the interlayer water molecules of deuterated vanadium pentoxide hydrate, V2O5.nD2O, was studied by solid-state deuterium NMR for the mono- and double-layer structures of the adsorbed water molecules. The rotational motion was anisotropic even at 355 K for both the mono- and double-layer structures. The 180° flipping motion about the C2-symmetry axis of the water molecule and the rotation around the figure axis, which makes an angle Ɵ with the C2-axis, occurred with the activation energy of (34±4) and (49±6) kJmol-1, respectively. The activation energies were almost independent of the mono- and double-layer structures of the water molecules, but the angle Ɵ made by the two axes varied from 33° for the monolayer to 25° for the double-layer at 230 K. The angle started to decrease above 250 K (e. g. the angle was 17 at 355 K for the double-layer structure). The results indicate that the average orientation of the water molecules in the two dimensional interlayer space depends on the layer structure and on the temperature. From the deuterium NMR spectrum at 130 K, the quadrupole coupling constant e2Qq/h = 240 kHz and the asymmetry parameter η= 0.12 were deduced. These values indicate the average hydrogen bond distance R(O H) = 2.0 Å for the D2O molecules in the 2D-interlayer space

The effect of partial methylation of the glycine amino group on crystal structure inN,N-dimethylglycine and its hemihydrate

2012 ◽  
Vol 68 (8) ◽  
pp. o283-o287 ◽  
Author(s):  
Vasily S. Minkov ◽  
Elena V. Boldyreva
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonds ◽  
Water Molecules ◽  
Amino Group ◽  
Asymmetric Unit ◽  
Partial Methylation ◽  
Space Groups ◽  
Carboxylate Groups ◽  
Anhydrous Compound ◽  
Additional Hydrogen

N,N-Dimethylglycine, C4H9NO2, and its hemihydrate, C4H9NO2·0.5H2O, are discussed in order to follow the effect of the methylation of the glycine amino group (and thus its ability to form several hydrogen bonds) on crystal structure, in particular on the possibility of the formation of hydrogen-bonded `head-to-tail' chains, which are typical for the crystal structures of amino acids and essential for considering amino acid crystals as mimics of peptide chains. Both compounds crystallize in centrosymmetric space groups (PbcaandC2/c, respectively) and have twoN,N-dimethylglycine zwitterions in the asymmetric unit. In the anhydrous compound, there are no head-to-tail chains but the zwitterions formR44(20) ring motifs, which are not bonded to each other by any hydrogen bonds. In contrast, in the crystal structure ofN,N-dimethylglycinium hemihydrate, the zwitterions are linked to each other by N—H...O hydrogen bonds into infiniteC22(10) head-to-tail chains, while the water molecules outside the chains provide additional hydrogen bonds to the carboxylate groups.

Sign in / Sign up

Export Citation Format

Share Document