01-2003.

QUANTITATIVE DETERMINATION OF THE PHOTOREDUCTION EFFECIENCY OF 4-BROMO-4'-FLUOROBENZOPHENONE. Chris E. Holm, Experimental Chemistry 463, Department of Chemistry, Oregon State University, Gilbert Hall, Corvallis, OR 97331-4003 

The photoreduction of 4-bromo-4'-fluorobenzophenone (Br-F-BP) to yield 4-bromo-4'-fluorobenzepinacol was studied using FTIR spectroscopy.  A peak at 1600cm-1 was used to measure the disappearance of Br-F-BP.  The photoreduction was carried out in a rotating rack UV-photoreactor which was calibrated with azoxybenzene, a compound with a known photoreduction efficiency. The photoreduction efficiency of 4-bromo-4'-fluorobenzophenone was measured at 46%.

02-2003.

PHOTOPHYSICS OF 1,3-BIS(2’,4’-DIMETHYLBENZOYL)BENZENE. Mark J. Abel, Department of Chemistry, Oregon State University, Corvallis, Oregon 97331. 

Benzophenone derivatives continue to attract attention for their interesting photophysical and photochemical properties. A new phenyl-diketone, 1,3-bis(2’,4’-dimethylbenzoyl)-benzene (I), has been synthesized and its photophysical properties explored. Unlike many benzophenone derivatives, (I) underwent no photochemistry. However, five singlet electronic states and one triplet were probed using a combination of absorption and phosphorescence measurements.

03-2003.

QUANTITATIVE FTIR ANALYSIS OF 4-FLUORO-4'-METHYLBENZOPHENONE. Nanako Ogi, Oregon State University, Department of Chemistry, Corvallis, Oregon 97331. 

4-fluoro-4'-methylbenzophonene has a high quantum efficiency and thus is a good starting material to prepare benzopinacol. Standard solutions and irradiated samples were analyzed by FTIR.  The area under the peaks which responded in a linear fashion to the increase in concentration or irradiation time was integrated. Finally the photoreduction quantum efficiency for this compound was determined to be 0.994 from the slope of the moles of reacted benzophenone versus moles of photons plot.

04-2003.

PHOTOREDUCTION OF 4,4’-DIMETHYLBENZOPHENONE TO DETERMINE THE PHOTOREDUCTION QUANTUM EFFICIENCY.
S.R. Robinson, Department of Chemistry, Oregon State University, Corvallis, OR   97331

A stock solution of 4,4’-dimethylbenzophenone was prepared from which three standards were made by dilution in isopropyl alcohol.   The stock solution was placed in four cylindrical quartz tubes for 350 nm UV irradiation.  Each of the four tubes underwent exposure for a set amount of time and from this data a value for the photoreduction efficiency for the ketone was determined to be 0.67.  

05-2003.

SYNTHESIS AND PURIFICATION OF 4-CHLOROBENZOPHENONE. John K. Yan, Department of Chemistry, Oregon State University, Corvallis, OR 97331.

4-chlorobenzophenone was prepared using the Friedel Crafts Acylation method with the starting materials benzoyl chloride, chlorobenzene and aluminum chloride as a catalyst.  From this procedure a mixture of two isomers, 4-chlorobenzopheone and 2-chlorobenzopenone was generated.  These two isomers were separated via an ethanol-water recrystalization procedure of the crude material.  Identification of the separated material was confirmed by IR spectroscopy and 1H-NMR.

06-2003.

APPLICATION OF AMINE-TETHERED BENZOPHENONE FOR CROSS-LINKING OF COLLAGEN PROTEINS. T. L. Suyama, OSU, Corvallis, Oregon  97331

Amine-tethered dimers of substituted benzophenones have recently been used to cross-link collagen proteins via reductive coupling at the ketones. The mechanism of such coupling reactions with peptides has been under investigation utilizing IR and UV/Vis spectrophotometry. The relevance of the experiments done in CH 463 to this type of research and possible outcomes, as well as benefits, of the mechanistic studies are discussed.

07-2003.

PHOSPHORESCENCE EMISSION STUDY OF 4-BROMOBENZOPHENONE IN VARIOUS SOLVENTS.  Nicola Maynard, Department of Chemistry, Oregon State University, Corvallis, Oregon, 97331.

When dissolved in a mixed hydrolytic solvent of water and ethanol, 4-bromobenzophenone exists as two H-bonded species. At reduced temperature, phosphorescence emission data was collected. The effect of increasing the polarity of the solvent caused the emission spectra to blue shift. The lowest excited singlet and triplet states for both species are of n-pi character. This suggests that the hydrogen bonds in the water bound species are stronger than those in the ethanol bound species. 

08-2003.

LIFETIME DIFFERENCES OF 4-CHLORO-4'-METHYLBENZOPHENONE IN POLAR AND NONPOLAR SOLVENTS.  J. Pan, Department of Chemistry, Oregon State University, Corvallis, Oregon 97333. 

A solvent study of the benzophenone showed relative differences in the UV lifetimes in a polar, protic solvent (ethanol) compared with a more nonpolar solvent mixture (EPA). A possible explanation of these differences is that they are due to hydrogen bonding of the nonbonding electrons on the carbonyl with the solvent, emphasizing the forbidden nature of the carbonyl UV electronic transitions between S₀, the ground state, and several excited states, S_n and T₁.

09-2003.

QUANTITATIVE DETERMINATION OF THE EXTENT OF PHOTOREDUCTION OF 4-BROMO-4-CHLOROBENZOPHENONE.  Melissa McEwan, Oregon State University, Department of Chemistry, Corvallis, Oregon 97331. 

Diphenyl ketones are often found to be quite photoreactive and can participate in a free radical-like hydrogen abstraction reaction in the presence of simple alcohols. This project will examine the photoreduction quantum efficiency of this ketone. Four 5.00 mL samples of a 0.0491 M stock solution in isopropyl alcohol were irradiated over the range of 1-20 min at 350 nm using quartz tubes in a Rayonet photoreactor. The standards and samples were analyzed for the ketone concentration on a Nicolet FTIR yielding a photreduction quantum efficiency of 0.55.

10-2003.

11-2003.

 12-2003.

13-2003.

FACTORS AFFECTING DOMAIN REORIENTATION IN FERROELASTIC UREA INCLUSION COMPOUNDS.
Mark Abel, Alexis Black, Mark Hollingsworth,  Kansas State University, 111 Willard Hall, Manhattan, KS 66506

Monoketone impurities in ferroelastic crystals of 2,10-undecanedione and 2-undecanone in urea (1,2/urea) have already been shown to speed domain reorientation.  Here, two new factors affecting domain wall motion are addressed: defects created during domain reorientation, and chiral twinning. Defects in daughter domains in 1,2/urea have been relaxed by mechanical vibration, removing the energy incentive for spontaneous reversion. A crystal system suitable for studying the effect of chiral twinning on domain reversion, 2,9-decanedione and  2-decanone in urea, is also introduced.