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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

An evaluation of efficiency of phenylenediamines as corrosion inhibitors for ASTM-A-179 steel in 1.0 N hydrochloric acid at room temperature

Al-Zubail, Saleh Abdullah. January 1986 (has links)
Thesis (M.S.)--Ohio University, March, 1987. / Title from PDF t.p.
22

The rearrangement of [alpha]-phenylallyl alcohol in aqueous dioxane

Dilgren, Richard Evarts, January 1959 (has links)
Thesis (Ph. D.)--University of Wisconsin--Madison, 1959. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 88-89).
23

Potent short-chain fatty acid-based histone deacetylase inhibitors as anti-tumor agents

Lu, Qiang, January 2005 (has links)
Thesis (Ph. D.)--Ohio State University, 2005. / Title from first page of PDF file. Document formatted into pages; contains xix, 116 p.; also includes graphics. Includes bibliographical references (p. 106-116). Available online via OhioLINK's ETD Center
24

The chemistry of 3-diazo-5-phenyl-1,2,4-triazole and 5-phenyl-1,2,4-triazol-3-ylidene /

Glinka, Jerome January 1981 (has links)
No description available.
25

Study of the kinetics of the [1,5]-sigmatropic phenyl rearrangement in 3,4-bis(para-substituted phenyl)-1,2,5-triphenyl-2,4-cyclopentadien-1-ols

Perfetti, Thomas Albert 07 April 2010 (has links)
A kinetic study of the suprafacial [1,5]-sigmatropic phenyl rearrangements of 3,4-bis- (para-substituted)-1,2,5-triphenyl-2,4- cyclopentadien-1-ols to 3,4-bis-(para-substituted)-2, 2,5-triphenyl-3-cyclopenten-1-ones, where the substituent were, t-butyl, methyl, hydrogen, chloro and bromo, has been performed at 180, 190, 200 and 210 ± 0.2° in tetraethylene glycol. The rearrangement was observed to be first order throughout the temperature range investigated, and the rate constants (k) at the temperatures used were found to be 8.057, 2.143, 2.930 and 6.456 x 10⁻⁴ sec⁻¹ for the t-butyl substituent; 4 7.700, 2.110, 3.434, and 6.581 x 10⁻⁴ sec⁻¹ for the methyl substituent; 0.909, 2.166, 3.678 and 6.448 x 10⁻⁴ sec⁻¹ for the unsubstituted alcohol; 1.469, 2.992, 5.989 and 11.12 x 10⁻⁴ sec⁻¹ for the chloro substituent; and 1.955, 3.215, 6.215 and 13.01 x 10⁻⁴ sec⁻¹ for the bromo substituent, respectively. . Calculations of the activation energy of this phenyl [1,5]-sigmatropic shift from the Arrhenius equation give values of 28.71, 30.31, 28.01, 29.38 and 27.49 kcal·mol⁻¹ for the above substituents respectively, while ΔH<sup>‡</sup> these phenyl migrations were 27.78, 29.39, 27.93, 28.45 and 26.56 kcal·mol⁻¹ respectively. ΔS<sup>‡</sup> values were also calculated to be -16.6, -13.1, -16.1, -14.0 and -17.8 eu, respectively for a mean temperature range of 453-483 ± 0.2°K. The isokinetic temperature was calculated to be 320°. Calculated rho (ρ) values for the sigmatropic migrations were -0.813, -0.400, -0.690 and -0.658 at 180, 190, 200 and 210 ± 0.2°C. These results are used to discuss both the mechanism of this rearrangement and the transition state for rearrangements in the pentaphenylcyclopentadienol system. Ina much broader sense these results and the results of previously documented sigmatropic rearrangements exhibiting electronic influences were used to formulate a general scheme to predict the outcome of those sigmatropic rearrangements that entail an electronic effect as seen in the rates of the above reactions. This scheme used as its basis the transition state approach invoking inductive and mesomeric arguments to rationalize the observed rates of the sigmatropic rearrangements of this dissertation, those of previously documented sigmatropic rearrangements and finally to predict a relative rate of rearrangements in general. Finally a mass spectral investigation of the fragmentation patterns of 1-para-phenylsubstituted 2,3,4,5-tetraphenyl-2,4-cyclopentadien-l-ols and 3,4-bis(para-substituted phenyl)-1,2,5-triphenyl-2,4- cyclopentadien-1-ols was undertaken. A continuum of two super imposable pathways with the choice of the major decomposition mode being determined by the electron donating or withdrawing ability of the substit- vent was established. Linear free energy relationships for mass spectral decomposition were presented as well as a justification for this behavior. / Ph. D.
26

Study of the oxidative degradation of 2,2,3,4,5-pentaphenyl-3- cyclopentenone by various oxidants ; and, [1,5]-sigmatropic phenyl rearrangements in 2- and/or 5-(p- or m-substituted phenyl)-1,3,4-triphenyl-2,4- cyclopentadien-1-ols: electronic effects at the migration terminus

Brubaker, William Frederick January 1982 (has links)
A Harmnett series comprised of seven 2- and/or 5-(p- or m-substituted phenyl)-1,3,4-triphenyl-2,4-cyclopentadien-l-ols was prepared and the ratio of the two-product mixture resulting from their thermal [1,5]- sigmatropic phenyl rearrangements was determined. In this system phenyl could migrate toward either of two positions, and the effect of the substituents upon the direction of migration was investigated to determine the extent of electronic effects in this neutral sigmatropic rearrangement. The results of these rearrangements are used to discuss the proposed transition state for phenyl rearrangements in the pentaphenylcyclopentadienol system. A strictly neutral transition state is proposed. In addition, the oxidative degradation of 2,2,3,4,5-pentaphenyl-3-cyclopenten-l-one by various oxidants was investigated. This substrate was found to be inert to all the reagents examined, with the exception of diacetyl chromate. The action of this oxidant upon the substrate produced an equimolar mixture of benzil, benzophenone, and benzoic acid in an overall yield of 40 to 42 percent. / Ph. D.
27

Synthesis and structure of transition metal siloxy compounds

Huang, Mingdong 19 February 1993 (has links)
Graduation date: 1993
28

Part I. A mechanistic study of the dedeuteration of 2,2,5,5-tetradeuterocyclopentanone by 3-dimethylaminopropylamine ; Part II. A study of multiple hydrogen bonding by 1,8-biphenylenediol /

Miles, David E. January 1964 (has links)
No description available.
29

Investigation of the synthesis and thermal rearrangements of 1,2,3,4,5-Pentaphenyl-2,4,-Cyclopentadiene Alkyl Ethers

Martin, Patricia January 1987 (has links)
A comparative synthetic study of a series of six 1,2,3,4,5-pentaphenyl-2,4-cyclopentadiene alkyl ethers was investigated. It was determined that the most efficient route to these ethers was not the most generally accepted route to ethers - the Williamson Reaction - but rather a solvolysis reaction between 1-bromo-1,2,3,4,5-pentaphenyl-2,4-cyclopentadiene and the appropriate alcohol. Thermal rearrangement of the ethers had been expected to rearrange by a [1,5]-sigmatropic shift of the phenyl group in the 1-position to yield the corresponding enol ether. However, this appeared to occur only as a trace in some cases. Rather, the major product of the thermal rearrangements of these ethers was actually the elimination product, the hydrocarbon, 1,2,3,4,5-pentaphenyl-2,4-cyclopentadiene. The elimination is most likely the result of a retro-ene reaction. / Ph. D. / incomplete_metadata
30

Investigation of the steric and/or electronic effects associated with the (1,5)-sigmatropic rearrangement of 1-substituted-2,3,4,5-tetraphenyl- 2,4-cyclopentadien-1-ols

Eagan, Robert Lee January 1986 (has links)
A series of eight l-substituted-2,3,4,5-tetraphenyl-2,4-cyclopentadien-l-ols were efficiently synthesized by the addition of the appropriate organometallic reagent to tetracyclone. It was determined that the steric and electronic nature of the migrating groups played a predictable role in the [l,5]-sigmatropic rearrangement of these compounds. Electron donating groups increased the rate of migration whereas electron withdrawing substituents were responsible for slowing the migration. Likewise, smaller groups accelerated the rate while bulky groups deterred the migration. Consequently, the experimental evidence supports the originally proposed charge separated transition state. The Michael addition of potassium cyanide to tetracyclone afforded upon protonation a diastereomeric mixture of the cis (kinetic product) and the trans (thermodynamic product) 4-cyano-2,3,4,5-tetraphenyl-2-cyclopenten-l-ones. Finally an efficient synthesis of 2,3,4,5-tetraphenyl-2(1H)-pyridinone (90%) resulted from the acid promoted addition of sodium azide to tetracyclone. The presence of an intermediate bicyclic triazoline eliminated the Schmitt mechanism as a viable reaction pathway. / Ph. D.

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