Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Alcohols active hydrogen determination

Use Analytical reagent for active hydrogen atoms in organic compounds also to determine water, alcohols, and amines in inert solvents. [Pg.1342]

Of the three steps in the mechanism, step 2 has the highest activation energy and is the slowest step. A reaction can proceed no faster than its slowest step, which is referred to as the rate-determining step. In the reaction of fert-bntyl alcohol with hydrogen chloride, formation of the carbocation by dissociation of the alkyloxonium ion is the rate-determining step. [Pg.144]

The dynamic NMR technique allows investigations on the rate of exchange between 3-substituted quinuclidinium ions and water. The rate of dissociation of amine/water (or amine/alcohol) complexes is determined by the free energy contribution from the p fa-dependent hydrogen bond breaking, and from dispersion forces between acceptor and donor which may be at the most 40% of the activation energy of the dissociation of the complex. Similar importance may be attributed to a term for the formation of a cavity prior to the dissociation of the complexes. [Pg.432]

Table IV presents the results of the determination of polyethylene radioactivity after the decomposition of the active bonds in one-component catalysts by methanol, labeled in different positions. In the case of TiCU (169) and the catalyst Cr -CjHsU/SiCU (8, 140) in the initial state the insertion of tritium of the alcohol hydroxyl group into the polymer corresponds to the expected polarization of the metal-carbon bond determined by the difference in electronegativity of these elements. The decomposition of active bonds in this case seems to follow the scheme (25) (see Section V). But in the case of the chromium oxide catalyst and the catalyst obtained by hydrogen reduction of the supported chromium ir-allyl complexes (ir-allyl ligands being removed from the active center) (140) C14 of the... Table IV presents the results of the determination of polyethylene radioactivity after the decomposition of the active bonds in one-component catalysts by methanol, labeled in different positions. In the case of TiCU (169) and the catalyst Cr -CjHsU/SiCU (8, 140) in the initial state the insertion of tritium of the alcohol hydroxyl group into the polymer corresponds to the expected polarization of the metal-carbon bond determined by the difference in electronegativity of these elements. The decomposition of active bonds in this case seems to follow the scheme (25) (see Section V). But in the case of the chromium oxide catalyst and the catalyst obtained by hydrogen reduction of the supported chromium ir-allyl complexes (ir-allyl ligands being removed from the active center) (140) C14 of the...
Thus, the enantiomeric contents in a pair of sulphoxides can be determined by the H NMR chemical shifts in the methine or methylene protons in the two diastereomeric complexes which are stabilized by the hydrogen bond between the hydroxyl and the sulphinyl groups (Scheme 13). Similarly, the enantiomeric purity and absolute configurations of chiral sulphinate ester can be determined by measuring the NMR shifts in the presence of the optically active alcohols. ... [Pg.564]


See other pages where Alcohols active hydrogen determination is mentioned: [Pg.938]    [Pg.114]    [Pg.119]    [Pg.114]    [Pg.244]    [Pg.192]    [Pg.233]    [Pg.198]    [Pg.299]    [Pg.110]    [Pg.131]    [Pg.106]    [Pg.115]    [Pg.326]    [Pg.108]    [Pg.242]    [Pg.328]    [Pg.518]    [Pg.943]    [Pg.371]    [Pg.298]    [Pg.173]    [Pg.462]    [Pg.335]    [Pg.321]    [Pg.216]    [Pg.45]    [Pg.86]    [Pg.293]    [Pg.487]    [Pg.73]    [Pg.236]    [Pg.756]    [Pg.486]    [Pg.104]    [Pg.26]    [Pg.423]    [Pg.504]    [Pg.10]    [Pg.164]    [Pg.339]    [Pg.154]    [Pg.241]    [Pg.55]    [Pg.693]   
See also in sourсe #XX -- [ Pg.299 ]




SEARCH



Activators determination

Active hydrogen

Activity determination

Activity, hydrogenation

Alcohol activation

Alcohols determination

Alcohols hydrogen

Alcohols hydrogenation

Hydrogen activated

Hydrogen activation

Hydrogen activity

Hydrogenation determination

Hydrogenation, activated

© 2024 chempedia.info