Synthesis and Characterization of Vanadium Oxide Gels from Alkoxy-Vanadate Precursors

1988 ◽  
Vol 121 ◽  
Author(s):  
C. Sanchez ◽  
M. Nabavi ◽  
F. Taulelle
Keyword(s):  
Vanadium Oxide ◽  
Synthesis And Characterization ◽  
Large Excess ◽  
Vanadium Oxide Gels ◽  
Hydrolysis Conditions ◽  
Hydrolysis Of ◽  
Controlled Hydrolysis ◽  
Alkoxide Precursors ◽  
Inorganic Precursors

ABSTRACTVanadium oxide gels are synthesized through vanadium oxo-alkoxide hydrolysis condensation processes. Different precursors and hydrolysis conditions lead to different sorts of gels. V0(0Amt)3 hydrolyzed with a large excess of water results in red jammy gels with a layered structure. They exhibit electronic and ionic behavior comparable to vanadium pentoxide gels from inorganic precursors. Hydrolysis of VO(OPrn)3 in an alcoholic medium, leads to orange transparent monolithic gels. They have a highly branched polymeric structure. Controlled hydrolysis of vanadium oxo-alkoxide precursors has the further advantage of giving good adherent thin films.

Synthesis and characterization of sodium vanadium oxide gels: the effects of water (n) and sodium (x) content on the electrochemistry of NaxV2O5·nH2O

2011 ◽  
Vol 13 (40) ◽  
pp. 18047 ◽  
Author(s):  
Chia-Ying Lee ◽  
Amy C. Marschilok ◽  
Aditya Subramanian ◽  
Kenneth J. Takeuchi ◽  
Esther S. Takeuchi
Keyword(s):  
Vanadium Oxide ◽  
Synthesis And Characterization ◽  
Vanadium Oxide Gels

Synthesis and characterization of new CaCO3/cellulose nanocomposites prepared by controlled hydrolysis of dimethylcarbonate

2010 ◽  
Vol 79 (4) ◽  
pp. 1150-1156 ◽  
Author(s):  
Carla Vilela ◽  
Carmen S.R. Freire ◽  
Paula A.A.P. Marques ◽  
Tito Trindade ◽  
Carlos Pascoal Neto ◽  
...  
Keyword(s):  
Synthesis And Characterization ◽  
Cellulose Nanocomposites ◽  
Hydrolysis Of ◽  
Controlled Hydrolysis

scholarly journals Characterization of Glycoside Hydrolase Family 5 Proteins in Schizosaccharomyces pombe

2010 ◽  
Vol 9 (11) ◽  
pp. 1650-1660 ◽  
Author(s):  
Encarnación Dueñas-Santero ◽  
Ana Belén Martín-Cuadrado ◽  
Thierry Fontaine ◽  
Jean-Paul Latgé ◽  
Francisco del Rey ◽  
...  
Keyword(s):  
Cell Wall ◽  
Schizosaccharomyces Pombe ◽  
Protein Characterization ◽  
Wall Material ◽  
Glycoside Hydrolase Family ◽  
Content Type ◽  
Hydrolysis Of ◽  
Controlled Hydrolysis ◽  
Hydrolase Family

ABSTRACT In yeast, enzymes with β-glucanase activity are thought to be necessary in morphogenetic events that require controlled hydrolysis of the cell wall. Comparison of the sequence of the Saccharomyces cerevisiae exo-β(1,3)-glucanase Exg1 with the Schizosaccharomyces pombe genome allowed the identification of three genes that were named exg1 + (locus SPBC1105.05), exg2 + (SPAC12B10.11), and exg3 + (SPBC2D10.05). The three proteins have different localizations: Exg1 is secreted to the periplasmic space, Exg2 is a membrane protein, and Exg3 is a cytoplasmic protein. Characterization of the biochemical activity of the proteins indicated that Exg1 and Exg3 are active only against β(1,6)-glucans while no activity was detected for Exg2. Interestingly, Exg1 cleaves the glucans with an endohydrolytic mode of action. exg1 + showed periodic expression during the cell cycle, with a maximum coinciding with the septation process, and its expression was dependent on the transcription factor Sep1. The Exg1 protein localizes to the septum region in a pattern that was different from that of the endo-β(1,3)-glucanase Eng1. Overexpression of Exg2 resulted in an increase in cell wall material at the poles and in the septum, but the putative catalytic activity of the protein was not required for this effect.

Synthesis and Characterization of Cobalamines with Phosphonito and Phosphinito Ligands

1992 ◽  
Vol 47 (1) ◽  
pp. 121-125 ◽  
Author(s):  
Sigrídur Jónsdóttir ◽  
Günter Klar
Keyword(s):  
Synthesis And Characterization ◽  
Optical Induction ◽  
Hydrolysis Of

Reactions of aquacobalamine with dimethyl and diphenyl phenylphosphonite and with methyl diphenylphosphinite lead to neutral complexes in which the partially hydrolyzed an ionic ligands [PPh(OR)(O)]- (R = Me, Ph) and [PPh2(O)]- are P-bonded to the cobalt(III) ion of the cobalamine moiety. Hydrolysis of the prochiral phosphonite already coordinated to the chiral cobalamine leads to two diastereomers which are formed in different yields. This optical induction is seen in the 1H and 31P{1H} N M R spectra.

Sign in / Sign up

Export Citation Format

Share Document