Five electrochemical test methods were evaluated for prediction of tinplate performance during this study. In addition, test packs were performed which provided some tinplate performance data. Three of the electrochemical methods gave inconclusive results in predicting tinplate performance. Two of these were anodic polarization in citric acid solutions involving different cell configurations. Another was anodic polarization of stress fractured samples in citric acid solution. One method, measuring the tin/steel alloy couple potential and current, gave results which appeared to predict tinplate performance, but the procedure was time consuming and the results were not easily reproducible. One method gave results which predicted tinplate performance and is recommended for use by the industry. This method measured tin dissolution rate and peak current as a function of time. The best performing tinplates gave lower peak currents and longer dissolution times. New electrochemical test cells were designed for four of the test electrochemical methods. One cell was designed to do five tinplate samples at once. A computerized test apparatus was developed for two of the test methods. This test apparatus greatly improved data handling and storage. A software program was configured to collect and evaluate data for the two computerized electrochemical methods.

The goal of this research project was to develop two converging synthetic methods to form C-glycosides, specifically aminomethyl C-glycosides. Part I. A novel catalyst system consisting of 2-hydroxypyridine (2-HP)/1,8-diazabicyclo (5.4.0) undec-7-ene (DBU)/molecular sieves can catalyze 1,3 proton transfers in organic solvents under neutral or slightly basic conditions, adjustable by the 2-HP/DBU ratio. In the presence of the catalyst system, 4,6-O-benzylidene- scD-glycopyranose (1), 4,6-O-isopropylidene- scD-mannose (12), and 4,6-O-isopropylidene- scD-gluco-pyranose (16) undergo Henry condensations with nitromethane to give acetal protected nitromethyl C-glycopyranosides (2, 13, and 17, respectively), which were characterized by their O-acetyl derivatives (5, 15, and 18, respectively). The Henry product from 4,6-O-benzylidene- scD-glucopyranose could be reduced, with retention of the 4,6-O-benzylidene protecting group, by a specially prepared form of elemental iron in aqueous tetrahydrofuran under CO$\sb2$ to aminomethyl C-glycopyranoside (16). This product was characterized by N-acetyl, peracetyl, and M-Cbz derivatives (7, 8, 9, 10) and was converted with diazonium salt to a triazene derivative (11). Nitroalkenes are only mechanistic intermediates in our condensations with nitromethane, but they undergo Michael additions with a second mole of nitromethane to give novel 4,6-O-alkylidene-1-deoxy-1,1-di(nitromethyl)- scD-glycitols (3 and 14) as side-products. Part II. 2,3:5,6-Di-O-isopropylidene mannofuranose (20), 2,3:4,6-di-O-isopropylidene mannopyranose (21), and 2,3,4,6-tetra-O-benzyl-glucopyranose each have been converted with 2-fluoro-1-methylpyridinium tosylate into anomerically pure pairs of glycosyl fluorides. Reaction of each anomeric mannopyranosyl and mannofuranosyl fluoride with Et$\sb2$AlCN in THF gave only the two (four component) anomeric mixtures of mannopyranosyl or mannofuranosyl cyanides and isocyanides, respectively. The pyranosidic four component mixture ($\alpha$-CN, $\alpha$-NC, $\beta$-CN, and $\beta$-NC) was completely separated by a combination of flash chromatography, crystallization, and/or preparative HPLC to give the individual components; in the furanose series, only the crystalline two component mixture of $\alpha$-furano cyanide and isocyanide could not be resolved. Isocyanides show two absorption maxima in their UV-spectra (195 and 230 nm) while cyanides show only the first. Cyanides, being C-glycosides, char more slowly on heated TLC plates than isocyanides.

The literature of polarography is so vast that any new publication in the field is likely to have an impact comparable to that of a raindrop falling on an ocean. If, however, through some alchemy of the imagination, the raindrop transformed to quicksilver and accompanied by discharge of "lightning"; and the "ocean" be a solution under carefully controlled conditions, then the effect may be measurable--even reproducible--and thus subject to rational interpretation. Since Jaroslav Heyrovsky's pioneer work in the early nineteen twenties, many such drops have fallen, bringing the science and art of polarography to its present highly developed state. Though superseded by gas chromatography in current popularity and publication rate in this country, polarography has many devoted followers and an almost inexhaustible and growing literature. Within the field, frontiers now being explored include alternating current polarography, oscillographic polarography, derivative polarography, controlled potential polarography, and non-aqueous systems. The present work is in the latter two categories.

Electronic excitation energy transfer from coumarins to xanthene dyes in different media has been investigated. Nonradiative energy transfer between coumarin 1 (d) and fluorescein (a), in 95% ethanol and in n-octanol takes place with critical transfer distances: 48.4 A (d-a) and 21.0 A (d-d) in 95% ethanol, and 46.4 A (d-a) and 25.4 A (d-d) in 1-octanol. The rate constants of nonradiative energy transfer and energy migration in these two solvents were compared with the rates of diffusion. Energy transfer in the three-component system coumarin 1/fluorescein/rhodamine B, was studied. The critical transfer distances between each two of the three components were: 48.4 A for coumarin 1/fluorescein; 42.2 A for coumarin 1/rhodamine B; and 65.5 A for fluorescein rhodamine B respectively. The quantitative description of this three component system indicates that, using our modified correction factors, the experimental data coincided satisfactorily with Kusba-Bojarski general equations of multi-component luminescence system. Nonradiative energy transfer between coumarin 6 and rhodamine 3B in poly-(methyl methacrylate) was studied. The fluorescence quantum yields of coumarin 6 in the monomer and polymer were measured to be 1.00 and 0.94 respectively. The calculated critical transfer distances were: 50.0 A (d-a) and 38.9 A (d-d) in the monomer; and 47.7 A (d-a) and 38.2 A (d-d) in the polymer. Unexpected high energy transfer efficiency was observed in the polymer. Environmental effects on the fluorescence of the fluorophore and the mechanism of energy transfer in fluid and rigid solutions were discussed. Fluorescence quantum yields of coumarin 1 in various alcohols were measured to be: 0.573 in 95% ethanol; 0.688 in ethanol; 0.826 in n-propanol; 0.814 in n-butanol; 0.818 in n-pentanol; 0.912 in n-hexanol; 0.846 in n-heptanol; 0.869 in n-octanol; 0.876 in n-nonanol and 0.882 in n-decanol. The fluorescence lifetimes of coumarin 1 in these alcohols, were calculated to be: 2.23; 3.20; 3.67; 3.42; 3.76; 3.47; 3.35; 3.88; 3.64; and 3.57 ns respectively. Solvent effects on the quantum yields were discussed.

Tens of thousands of metric tons of highly radioactive, nuclear waste have been generated in the United States. Currently, there is no treatment or disposal facility for these wastes. Of the radioactive elements in high-level nuclear waste, neptunium (Np) is of particular concern because it has a long half-life and may potentially be very mobile in groundwaters associated with a proposed underground disposal site at Yucca Mountain, Nevada. Aqueous Np concentrations observed in previous, short-term solubility experiments led to calculated potential doses exceeding proposed long-term regulatory limits. However, thermodynamic data for Np at 25°C showed that these observed aqueous Np concentrations were supersaturated with respect to crystalline NpO 2 . It was hypothesized that NpO 2 is the thermodynamically stable solid phase in aqueous solution, but it is slow to form in an aqueous solution of NpO 2 + on the time scale of previous experiments. The precipitation of NpO 2 would provide significantly lower aqueous Np concentrations leading to calculated doses below proposed regulatory limits. To test this hypothesis, solubility experiments were performed at elevated temperature to accelerate any slow precipitation kinetics. Ionic NpO 2 + (aq) was introduced into very dilute aqueous solutions of NaCl with initial pH values ranging from 6 to 10. The reaction vessels were placed in an oven and allowed to react at 200°C until steady-state aqueous Np concentrations were observed. In all cases, aqueous Np concentrations decreased significantly from the initial value of 10 −4 M. The solids that formed were analyzed by x-ray powder diffraction, x-ray absorption spectroscopy, and scanning electron microscopy. The solids were determined to be high-purity crystals of NpO 2 . This is the first time that crystalline NPO 2 has been observed to precipitate from NpO 2 + (aq) in near-neutral aqueous solutions. The results obtained demonstrate that Np will precipitate as NpO 2 in aqueous solutions thereby leading to significantly lower aqueous Np concentrations.

The increasing awareness of the close inter-relationships between biological activity and chemical reactions has resulted in a rapidly growing pursuit of biochemical knowledge. Research in the related fields of medicine, virology, pharmacy, and biophysics is expanding at a rapid rate. Problems related to food production for an exploding population, space explorations, world health issues, the utilization of the resources of the oceans, and the proper employment of energy sources have spurred man to delve deeper into the secrets of creation. The mysteries of life itself are slowly being revealed through finding in egentic studies. With this ever expanding biochemical and related research comes the concomitant requirement for the new and better analytical techniques. Already quantitative determinations are on the nanogram level. Many procedures are semi- or fully automated. In this framework of recent advances, the desire to develop an analytical procedure useful to mankind was kindled. In particular, the importance of iodine in certain essential biological systems and biochemical mechanisms led to the problem of this research. The purpose of this study was to determine the possibilities of utilizing fluorescein as an “indicator” in the quantitative determination of sub-micro amounts of iodine by an existing colorimetric technique. Furthermore, the application of this procedure to the determination of micro-amounts of simple carbohydrates, as glucose was considered a very real possibility.

The purpose of the present work was to (1) determine the feasibility of performing radiometric titrations using low activity radioisotopes and inexpensive equipment; (2) develop a workable procedure for performing ·radiometric titrations in the classroom; and (3) assemble the basic radioactive concepts needed so the content could be used in a chemistry course of study. The limited work done previously with radiometric titrations has used solutions of high specific activity and relatively large volumes of solution. The use of high activity radioisotopes creates problems of radioisotope procurement, shielding, handling and disposal. The use of high activity radioisotopes required special training and licensing. This imposed a severe limitation on the number of persons that could perform radiometric titrations. Thus to make this technique available to a large number of classroom teachers and other similarly qualified persons, it was imperative that a procedure be devised that would allow radiometric titrations to be performed using low activity, license free radioisotopes. The low activity of the license free radioisotopes necessitated the delineation of the physical conditions that could best utilize the limited activity of the solution. The amount of radioisotope used was determined as an amount low enough to simplify or eliminate the problems of procurement, shielding, handling and disposal but yet have a sufficient count rate to enable precise and accurate results. A physical setup was devised that met the desired criteria. Using this setup, the feasibility of radiometric titrations was determined for precipitation reactions using, as the indicator, one or more of the following radioisotopes: Ca-45; I-125; I-131; Ag-110; Cl-36; W-185; Tl-204; and S-35. The isotopes selected allowed delineation of systems having wide variation of emission type and energies. Thus in addition to the systems deliniated, this allows the prediction of the usefulness of isotopes for other systems than those investigated. The systems using Ca-45, S-35, and Tl-204 were found capable of giving very good results. A field study was· conducted in which a total of sixty-two students performed a radiometric titration. Their average results agreed almost exactly with the accepted value. Their average deviations were of the same order of magnitude as the accuracy reported in many studies using radioisotopes of high activity. The effects of complexation and pli dependence was also studied for some of the systems. The affect on the titration curve shape agrees well with the theoretical predictions. Therefore, in addition to the deliniation of new systems for radiometric titrations, this study provided a method of teaching radioactive concepts in a manner that allows safe student participation. Student participation not only allows the teaching of radioactive concepts, the techniques of radioactive solution handling and disposals, and an analytical method, but also allows ready observation of the factors affecting solubility.

New methods were developed to purify histone H4 from chicken erythrocyte nuclei. Hydroxylapatite gel sedimentation required approximately one hour to isolate whole histones from chromatin as opposed to days when the traditional HTP chromatography was employed. In addition, a selective membrane ultrafiltration technique was proven to be as effective as the HTP gel in separating histones from DNA. A reversed-phase high performance liquid chromatography elution profile was developed to isolate histone H4 from other histones. A linear gradient from 95% H2O : 5% CH3CN (both solvents contained 0.1% v/v trifluoroacetic acid) to 42% H2O : 58% CH3CN through a C18 column (Axxiom, 3μm, spherical particles, 60 Å pore size, 4.6 mm x 100 mm) at a flow of 1 ml/min for 1 hour yielded electrophoretically pure histone H4. The binding of 32PO4 to purified histone H4 was studied by equilibrium partitioning across a 5 kD MWCO semipermeable membrane in an Amicon micro-partition system. A linear Scatchard plot was obtained indicating a stoichiometric ratio of 5 molecules of ligand to every molecule of histone H4 (n = 5.4) and a dissociation constant in the millimolar range (Kd = 2.8 x 10-3 M). The 31P-NMR linewidths increased markedly and progressively as a function of histone H4 concentration. However, the 31P peak became narrower, although never back to the original value for PO4 alone, when the [PO4] : [H4] ratio was greater than 5. At ratios higher than 5 : 1, free phosphate contributes significantly to the observed relaxation rate. Hence, both types of studies suggest the same 5 to 1 stoichiometry for the inorganic phosphate-histone H4 interaction. Two-dimensional high-resolution NMR was used to assign all resolvable peaks from a 500 MHz 1H-NMR spectrum of N-acetyl-AKRHRKV, an oligopeptide that resembles an important part of the N-terminal end of histone H4. Binding of this peptide segment with inorganic phosphate was studied by 31P- and 1H-NMR. Analysis of 31P-NMR linewidths with added peptide revealed a dissociation constant of 7.04 x 10-2 M. The apparent spin-spin relaxation times for free, TF2,and histone-bound phosphate, TB2. were calculated to be 28.7 mseconds and 6.3 mseconds respectively. 1H-NMR TOCSY and NOESY spectra indicated that this peptide adopts a loop conformation with the C-terminal valine H-bonded to the histidine carbonyl. The involvement of the histidine imidazole ring in phosphate binding is also indicated by the shifts of the H2 and H4 protons in the presence of PO4.

Recent work in this laboratory has centered about the platinum metals and their complexes. The current activity in thin layer chromatography, and especially the work of Seiler in using the technique for inorganic applications, led to speculation regarding the separation and identification of the platinum metal ions by thin layer chromatography. Specifically, then, the purpose of this study was twofold: (1) to find a suitable adsorbent and solvent system to separate some or all of the platinum metal ions; (2) to find appropriate locating agents, so that once the separation had been accomplished, the ions could be identified.

A search of the literature revealed that no study has sought to measure and compare the polarographic solvent properties of the anhydrous aliphatic diamines. In fact, there has been no reported instance of the use of anhydrous 1,3-propanediamine or 1,4-butanediamine in any electro- chemical system.