scholarly journals Electronic Structures of η7-Cycloheptatrienyl η5-Cyclopentadienyl Derivatives of Vanadium and Tantalum As Studied by Solution-Phase and Vapor-Phase Photoabsorption Spectroscopy in the Ultraviolet and Visible Regions.

1997 ◽  
Vol 16 (9) ◽  
pp. 1996-1996 ◽  
Author(s):  
Jennifer C. Green ◽  
Sergey Yu. Ketkov
Keyword(s):  
Vapor Phase ◽  
Electronic Structures ◽  
Solution Phase ◽  
Derivatives Of

Vapor-phase and solution-phase UV spectroscopic studies of η5-pentadienyl derivatives of iron and ruthenium

1998 ◽  
Vol 563 (1-2) ◽  
pp. 209-217 ◽  
Author(s):  
Sergey Yu Ketkov ◽  
Richard D Ernst ◽  
Lothar Stahl ◽  
Wimonrat Trakarnpruk
Keyword(s):  
Vapor Phase ◽  
Spectroscopic Studies ◽  
Solution Phase ◽  
Derivatives Of

The relative rates of bromination of cyclohexane and cyclopentane with molecular bromine. Comparison of the reactions in solution and in vapor phase

1981 ◽  
Vol 59 (9) ◽  
pp. 1368-1374 ◽  
Author(s):  
Dennis D. Tanner ◽  
Tomoki C-S. Ruo ◽  
Hideki Takiguchi ◽  
Andre Guillaume
Keyword(s):  
Vapor Phase ◽  
Hydrogen Bromide ◽  
Bromine Atom ◽  
Relative Rate ◽  
Solution Phase ◽  
Molecular Bromine ◽  
Transfer Rates ◽  
Relative Rate Constants ◽  
Halogenated Alkanes ◽  
Relative Transfer

The relative rates of transfer of the cyclopentyl radical with molecular bromine and hydrogen bromide (k2′/k−1′) and with hydrogen tribromide and hydrogen bromide (k3′/k−1′) have been determined. The relative transfer rates are compared with the analogous values previously reported for the reactions of cyclohexyl radicals (k2/k−1 and k3/k−1). Utilizing the values of k2′/k−1 and k2/k−1 the competitive vapor phase rates of bromine atom abstraction of hydrogen from the two substrates could be obtained. An expression using a combination of the five sets of relative rate constants was used to determine the effect of competitive cage reversal which occurs in the solution phase bromination of the two substrate radicals with caged hydrogen bromide. For two structurally similar radicals, cage reversal (internal return) was found to affect the relative rates of bromination by 30%, while the relative transfer rates, although differing each by a factor of two, fortuitously nearly cancel each other's effect.The effect of both internal and external reversal reactions on the relative rates of bromination of structurally dissimilar substrates, halogenated alkanes and their parent hydrocarbons, is discussed.

Reactivity of methyl derivatives of nitrogenous heterocycles in vapor-phase catalytic oxidation

1986 ◽  
Vol 22 (1) ◽  
pp. 63-66
Author(s):  
L. Ya. Leitis ◽  
R. A. Skolmeistere ◽  
L. O. Golender ◽  
D. P. Yansone ◽  
P. A. Meksh ◽  
...  
Keyword(s):  
Catalytic Oxidation ◽  
Vapor Phase ◽  
Methyl Derivatives ◽  
Derivatives Of

A proton magnetic resonance estimate of the extent of intramolucular hydrogen bonding in derivatives of 2-trifluoromethyl phenol. Solvent effects

1976 ◽  
Vol 54 (14) ◽  
pp. 2243-2248 ◽  
Author(s):  
Ted Schaefer ◽  
J. Brian Rowbotham
Keyword(s):  
Free Energy ◽  
Hydrogen Bonding ◽  
Vapor Phase ◽  
Coupling Constants ◽  
Spin Coupling ◽  
Hydroxyl Group ◽  
Spin Coupling Constants ◽  
Hydroxyl Protons ◽  
Spin Spin Coupling ◽  
Derivatives Of

The long-range spin–spin coupling constants between hydroxyl protons and ring protons or fluorine nuclei are used to establish the conformer populations in iodine and brornine derivatives of 2-trifluoromethylphenol in C6H12, CCl4, and C6D6 solutions. The sequence Cl, [Formula: see text] is established for the so-called hydrogen bonding preferences of the hydroxyl group in 2,4,6-trisubstituted phenols, the corresponding free energy sequence being −ΔG = 1690, 1690 > 1300 > 1230 > 0 ± 200 cal/mol at 32 °C in CCl4 solution. An indirect estimate of the free energy differences in the vapor phase suggests the sequence −ΔG = 2800, 2800 > 2400 > 2300 > 1100 ± 300 cal/mol; the latter value meaning that the hydroxyl group in 4-bromo-2-trifluoromethylphenol prefers the CF3 group by this amount in the vapor phase. Benzene interacts preferentially with the OH group in this compound to the extent of 1300 cal/mol (ΔG), referenced to the vapor phase.

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