| dc.description.abstract | The purpose of Chapter 1 is to create a bicyclic, two-coordinate phosphorus derivative in the
form of a 2,3-benzo-l,4,5,6-tetraphenyl-7-phosphanorbomadiene anion and measure its
experimental 3,P NMR chemical shift. This value is compared to a theoretical NMR shift of
8 +1085 ppm calculated by D.B. Chesnut at Duke University using ab initio quantum mechanics.
This is the largest downfield chemical shift ever predicted for an organophosphorus compound.
Diphenylacetylene was reacted with solid Li to produce l,4-dilithio-l,2,3,4-tetraphenylbutadiene
(LTPB). Then, LTPB was reacted with dichlorophenylphosphine to produce pentaphenylphosphole,
which was oxidized with 30% hydrogen peroxide to pentaphenylphosphole oxide.
Next, this oxide was reacted with benzyne to synthesize 2,3-benzo-l,4,5,6,7- pentaphenyl-7-
phosphabicyclo[2.2. l]hept-5-ene oxide which has a 31P NMR chemical shift of 8 + 96 ppm.
Reduction of this product using trichlorosilane afforded products with 31P NMR chemical shifts
o f 8 +57 and +58 ppm which could possibly be the two isomers of 2,3-benzo-l,4,5,6,7-
pentaphenyl-7- phosphabicyclo[2.2. l]hept-5-ene. Further reduction of these crude products was
attempted using elemental sodium but with no success. Because of a time restraint and the
difficulty in obtaining a stable 7-phosphanorbomadiene, the bicyclic, two- coordinate anionic
phosphorus derivative could not be synthesized and proven to have a 31P NMR chemical shift of
8+1085 ppm.
Amino acid racemization occurs according to the environment to which the amino acids are
exposed. Racemization occurs when laevorotary-forms of amino acids are converted to
dextrorotary-forms of amino acids by exposure to weak acids or bases, over time. This
conversion in ancient samples was found to take place at the same rate as degradation of DNA.
It was found [1] that if the D/L ratio of aspartic acid was lower than 0.08 in a bone or tissue
sample, viable DNA could be extracted from it In Chapter 2 this research attempted to
derivatize enantiomeric amino acids with L-Marfey’s Reagent to produce diastereomers that
could be separated using capillary electrophoresis, gas chromatography, and high pressure liquid
chromatography. Problems with the equipment, contamination, unrepeatable results and a
variety of unknown factors plagued this portion of the research. This mode of testing for the
presence of viable DNA was deemed a non-viable process. | |
