Pentacarbonylacryloylferrocenetungsten(0) complex was synthesized photochemically from hexacarbonyltungsten(0) and acryloyferrocene (acfc). UV irradiation of W(CO)6 in the presence of acryloylferrocene at 10 oC for 4 hours in n-hexane solution generates the W(CO)5(&amp / #61544 / 2-acfc) complex as the sole monosubstitution product of the photolysis, as monitored by FT-IR spectroscopy. The product complex could be isolated from the reaction solution and characterized by IR, Raman, 1H-NMR, 13C-NMR spectroscopies, mass spectrometry and elemental analysis. The complex was found to be unstable in solution and to decompose to the parent W(CO)6 complex and free acryloylferrocene molecule. The instability of the complex makes its isolation as analytically pure substance difficult. In order to stabilize the tungsten-olefin bond, trimethylphosphite was introduced as a donor ligand into the molecule. Thus, a complex containing a donor ligand in addition to the olefinic ligand was prepared starting with W(CO)6, trimethylphosphite, and acryloylferrocene. UV irradiation of W(CO)5[P(OMe)3] with acryloylferrocene in n-hexane solution at room temperature generates W(CO)4[P(OMe)3](&amp / #61544 / 2-acfc), which was isolated from the reaction solution and characterized by IR, 1H-NMR, 13C-NMR spectroscopies and mass spectrometry. The complex was found to have a cis arrangement of four CO groups in the pseudo-octahedral geometry. However, the cis-W(CO)4[P(OMe)3](&amp / #61544 / 2-acfc) complex was found to be less stable than W(CO)5(&amp / #61544 / 2-acfc).

Thesis (Ph. D.)-- University of Washington, 2005. / Vita. Includes bibliographical references (leaves 108-114).

Judicious addition of photolabile caging groups (PCGs) to protect biologically im- portant molecules, has enabled the development of many powerful chemical tools for the study of biological processes. These tools have the potential to be activated in a cellular setting by irradiation with light of appropriate wavelengths, restoring functionality, with excellent spatial and temporal control. This D. Phil. dissertation highlights two biologically relevant examples where PCGs can be applied: (i) 4,5-dimethoxynitrobenzyl (DMNB) caged derivatives of GSH and ESG, were synthesised and uncaging of the DMNB group at 350 nm to reveal the free α-carboxylic acid of the glycine residue was demonstrated. These molecules have the potential to probe the binding mode within the KefC KTN binding domain, a ligand-gated K+ efflux system, critical for bacterial response to electrophilic assault. The molecules are currently with collaborators awaiting further evaluation. (ii) The wavelength-dependent application of PCGs toward the study of protein post- translational modifications (PTMs) was developed. PTMs modulate protein function and have a ubiquitous role in a diverse range of cellular functions. A wavelength selective sequential pair of PCGs was developed and demonstrated in a tripeptide, using the diethylamino coumarin (DEACM), which was cleaved at 420 nm, and the DMNB caging group, which was subsequently cleaved at 350 nm. A chromatically orthogonal pair of PCGs, with possible applications in both organic synthesis and biological systems, incorporating the BODIPY-based and DEACM caging groups, which could be cleaved at 530 nm and 420 nm, respectively, was also developed. Photolysis was conducted on a tripeptide and hexapeptide and an in vitro application was demonstrated where when caged, the peptide was not susceptible to peptidolysis when incubated with enzymes. Following irradiation at 420 nm, the DEACM group was uncaged and the peptide underwent peptidolysis in the presence of Endoproteinase AspN, whereas following irradiation at 530 nm to uncage the BODIPY group, the peptide underwent peptidolysis in the presence of Endoproteinase LysC. These results not only provide conclusive evidence of the ability of this pair of caging groups to act in a wavelength orthogonal sense but also demonstrates the potential applicability of the pair to biochemical studies. This pair of PCGs represents the first example of an orthogonal pair of caging groups where both PCGs could be cleaved, at wavelengths longer than 400 nm, in a sequence independent manner.

Contaminants of emerging concern (CECs) are an unregulated suite of constituents frequently detected in environmental waters, which possess the potential to cause a host of reproductive and developmental problems in humans and wildlife. Degradation pathways of several CECs are well-characterized in idealized laboratory settings, but CEC fate and transport in complex field settings is poorly understood. In the present study I use a multi-tracer solute injection to study and quantify physical transport and photodegradation in a wastewater effluent-impacted stream in Ankeny, Iowa. Conservative tracers are used to quantify physical transport processes in the stream. Use of reactive fluorescent tracers allows for isolation of the relative contribution of photodegradation within the system. Field data were used to calibrate a one-dimensional transport model, and forward modeling was then used to predict the transport of sulfamethoxazole, an antibiotic in the effluent which is susceptible to photolysis. Results show that accurate predictions of reactive CECs at the scale of stream reaches can be made using the fate and transport model based on field tracer studies. Results of this study demonstrate a framework that can be used to couple field tracer and laboratory CEC studies to accurately predict the transport and fate of CECs in streams.

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The lethal effect of ultraviolet (UV) light on microorganisms is well known and many studies have been undertaken into the effects of UV induced damage. Most of this work has been experimental; by comparison relatively little theoretical work has been undertaken to analyse the kinetics of the UV inactivation process, or to develop quantitative methodologies to support the experimental work. This paper presents a new and simple model for quantifying the photolysis rate. A theoretical study is also presented in this paper which quantifies photolysis rates for E. coli O26 and E. coli O157:H7. This study uses experimental data collected by Tosa and Hirata, and reveals the photolysis rate for E. coil O26 during the UV irradiation process to be 4.69 x 10(-3) m2 J(-1). By comparison, E. coli O157:H7 is much more susceptible to UV induced damage than E. coli O26, having a photolysis constant of only 2.09 x 10(-3) m2 J(-1).

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