Complexes of 2,2-cis [Rh2(N{C6H5}COCH3)4] bound to benzonitrile, ortho-tolunitrile, and meta-tolunitrile were synthesized and characterized using X-ray crystallography, IR spectroscopy, and proton NMR. The crystal structures of 2,2-cis [Rh2(N{C6H5}COCH3)4]•2NCC6H5, 2,2-cis [Rh2(N{C6H5}COCH3)4]•2NC{2-CH3}C6H4, and 2,2-cis [Rh2(N{C6H5}COCH3)4]•2NC{3-CH3}C6H4 were solved using a Rigaku Mercury375R/M CCD XtaLab Mini Diffractometer. The 2,2-cis [Rh2(N{C6H5}COCH3)4]•2NCC6H5 complex had unit cell dimensions of a=10.2115(7) Å, b=9.9667(7) Å, c=21.367(2) Å, and β=100.971(7)° with a P21/n space group. The 2,2-cis [Rh2(N{C6H5}COCH3)4]•2NC{2-CH3}C6H4 complex had unit cell dimensions of a=10.3625(8) Å, b=10.0489(7) Å, c=21.611(2) Å, and β=100.868(7)° with a P21/n space group. The 2,2-cis [Rh2(N{C6H5}COCH3)4]•2NC{3-CH3}C6H4 complex had unit cell dimensions of a=10.849(3) Å, b=11.530(3) Å, c=12.259(3) Å, α=117.562(8)°, β=103.061(7)°, and γ=101.562(7)° with a P-1 space group. Each rhodium atom had approximate octahedral coordination and was bound to another rhodium atom along with two equatorially bound nitrogens and two equatorially bound oxygens and one axially bound nitrogen that was a part of the nitrile.

Placing degree constraints on the vertices of a path allows the definitions of uphill and downhill paths. Specifically, we say that a path π = v1, v2,...vk+1 is a downhill path if for every i, 1 ≤ i ≤ k, deg(vi) ≥ deg(vi+1). Conversely, a path π = u1, u2,...uk+1 is an uphill path if for every i, 1 ≤ i ≤ k, deg(ui) ≤ deg(ui+1). We investigate graphical parameters related to downhill and uphill paths in graphs. For example, a downhill path set is a set P of vertex disjoint downhill paths such that every vertex v ∈ V belongs to at least one path in P, and the downhill path number is the minimum cardinality of a downhill path set of G. For another example, the downhill domination number of a graph G is defined to be the minimum cardinality of a set S of vertices such that every vertex in V lies on a downhill path from some vertex in S. The uphill domination number is defined as expected. We determine relationships among these invariants and other graphical parameters related to downhill and uphill paths. We also give a polynomial time algorithm to find a minimum downhill dominating set and a minimum uphill dominating set for any graph.

Mira-type stars are luminous red giants that have pulsation periods that last anywhere between 100 and 700 days. The irregular behavior of their periods and atmospheric properties flag them as excellent candidates for astrophysical studies of non-spherical stars. This paper focuses on the linear polarization of light emitted from three Mira- type stars: Mira itself, R Leo, and V CVn. Polarimetric data from the University of Wisconsin’s Half-Wave Spectropolarimeter (HPOL) database, as well as other archives of polarimetric data, provide us with insight into the atmospheric and geometrical prop- erties of these three stars. We were able to study the net polarizations and position angles alongside light curves provided by AAVSO. The observed variable polarization is a clear signature of evolving aspherical geometries for these stars. However, we found a major surprise concerning the polarimetric characteristics in V CVn, which suggest that V CVn is unlike a traditional Mira-type variable star. We end with an exploration of new possibilities regarding the atmospheric properties of V CVn.

No abstract.

The objective of my thesis was to add to a catalogue of molecular structures that is being compiled as a part of the Standoff Detection Project. The optimized geometry of P8O20 and P20O20 were calculated using restricted Hartree-Fock Theory, using the standard quantum mechanics and computational chemistry programs ECCÈ and NWChem. Unfortunately, due to the extremely time consuming nature of these calculations there was not enough time to complete the calculations for P24O48 and P24O60.

Photodynamic therapy (PDT) employs photosensitizing drugs for treating cancer. Once introduced into the body and localized in tumor cells, these photosensitizers are irradiated with light to produce active singlet oxygen radicals which kill cancer cells. The current drugs used in PDT have low quantum yield and always require a high energy radiation (normally laser). There is always a need for more effective drugs that have a high quantum yield and can be activated by visible light, in order to eliminate side effects caused by laser radiations. In this work we synthesized derivatives of phenothiazine and phenothiazinium chromophores from the commercially available phenothiazine (1). These derivatives include: 3,7-dibromophenothiazinium perbromide (2), N-acetyl phenothiazine (5), N-acetyl-3,7-dibromophenothiazine (6), 3,7-dinitrophenothiazine (10), N-acetyl-3,7-dinitrophenothiazine (11), N-acetyl-3,7-diaminophenothiazine (12), thionine chloride (15) and 3,7-phenothiaziniumdinitrile (14). Synthesis of 3,7-phenothiazinium dicarboxylic acid was attempted using 1 and 15 as starting materials by exploring various synthetic routes for carboxylic acids.

Anodic stripping voltammetry (ASV) is an electroanalytical method used in the determination of trace metals in solutions volumes of 20 milliliters or less. Generally, 10-6 M concentrations are routinely analyzed. The analysis of Zn(II), Cd(II), and Cr(III) by ASV was Investigated, and the effects of introducing the bridging ligands, cyanide and thiocyanate into solutions of these metal ions was examined. These effects include a cathodic shift in the reduction potentials of the metals, and ASV signal changes ranging from small increases in peak currents to a total loss of peak-current signals, depending on the concentration of the ligand added.

1-(9-Anthry1)-2-nitropropene and 1-(3-pyridy1)-2-nitropropene were prepared and irradiated with ultraviolet light. Irradiation of 1-(9-anthry1)-2-nitropropene, in which the ethylene group was twisted out of the plane of the aromatic ring and the resonance stabilization between the ethylene group and the aromatic ring was limited , gave only cis-trans isomerization. Irradiation of 1-(3-pyridy1)-2-nitropropene gave an oxime. The effect of added HC1 on the reactivity of 1-(3-pyridy1)-2-nitropropene showed that the rate for the formation of oximinoketone was decreasing., while irradiation of 1-phenyl-2-nitropropene with HC1 showed that the rate for the formation of oximinoketone was increasing. From these observation, steric factors and resonance factors are postulated to have a rather large influence on the nitro-nitrite rearrangement and the extent to which it will occur.

Edible oils are easily oxidized when used for frying. Oxidation originates with double bonds present in unsaturated fatty acids. A new NMR method is presented which offers potential for determining the products of oil oxidation. High resolution fourier transform nuclear magnetic resonance (FT-NMR) and fourier transform infrared (FT-IR) spectroscopy have found increasing use in biochemistry. One pure fat, trioleoylglycerol, was heated at 160°C in the presence of air Samples were taken for FT-NMR and FT-IR analyses at 4, 10. 20. 25, 35, 50, 70 and 100 hours. Proton, Carbon-13 and several types of two-dimensional FT-NMR spectra were obtained using a JEOL 270 Mhz instrument. The spectra suggest initial oxidation occurs by an allyl free radical mechanism facilitating the formation of epoxide and peroxide products.

It has been postulated that acetone is the best solvent for the photochemical rearrangement of β-methy1-β-nitrostyrene to 1-phenyl-1, 2-propanedione-1-oxime and it has been postulated to be a sensitizer for this rearrangement. It has also been suggested that the methyl group on the beta-carbon is required for the proper orientation of the nitro group for rearrangement. The irradiation of β-methyl-β-nitrostyrene in several solvents has been studied and the yield of oxime has been recorded. It has been found that several solvents gave yields of oxime higher than that recorded for acetone. We do not, therefore, believe acetone to be necessary to sensitize the rearrangement. The fact that essentially quantitative yields of 1-phenyl-1, 2-propanedione-1-oxime were obtained in aqueous acetone, ethanol and methanol (the yield of oxire in diethyl ether was increased from 45% to 85.6% by the addition of 1% of water prior to irradiation) leads us to believe that water plays an important role in the formation of the oxime. The role of the s-methyl group was verified and the effect of oxygen on the rearrangement was investigated. Irradiation of β-methyl-β-nitrcstyrene in aqueous ethanol under an oxygen stream gave benzaldehyde, benzoic acid and 1-phenyl-1, 2-propanedione as the major products. c oxire could be detected in the reaction mixture.