The calcination of calcium carbonate in a cement or a lime kiln uses approximately two to four times the theoretical quantity of energy predicted from thermodynamic calculation depending upon the type of the kiln used (1.4 x 10^6 Btu/ton theoretical to 6 x 10^6 Btu/ton actual). The objective of this research was to attempt to reduce the energy required for the calcination by 1. decreasing the calcination temperature of calcium carbonate, and/or 2. increasing the rate of calcination at a specific temperature. Assuming a catalytic enhancement of 20 percent in the industrial applications, an energy savings of 300 million dollars annually in the United States could be reached in the cement and lime industries. Three classes of compounds to date have shown a positive catalytic effect on the calcination of calcium carbonate. These include alkali halides, phospho- and silico-molybdate complexes, and the fused carbonates system.

This study is concerned with certain factors affecting the content of lactobacillic acid in Lactobacillus plantarum. Three main areas of investigation are reported herein. The effects of both the oxygen tension and the pH of the culture medium on the accumulation of lactobacillic acid were determined. In addition, monolayer studies were conducted to determine the influence of cyclopropane fatty acid content on the molecular packing of membrane lipids.

A series of dihydroxy bridged copper(II) complexes of the type [(L)Cu(OH)₂Cu(L)]x₂ * nH₂0, where L is 2,2'-bipyridine, 4,4'-dimethyl-2,2'-bipyridine or 1,10-phenanthroline, x is a counter ion, and n is the number of water molecules, was synthesized. In the case of monohydroxy bridged copper(II) complexes, we have found a new method of synthesis for [ (L)₂Cu(OH)Cu(L)₂ ] (ClO₄)₃, where L is 2,2'-bipyridine or 1,10-phenanthroline. We have synthesized five new monohydroxy bridged copper(II) complexes, thus increasing the number of monohydroxy bridged copper(II) complexes to nine. All complexes have been characterized by infrared spectroscopy, UV-visible spectroscopy, magnetic moments, and elemental analysis. The electron spin resonance results establish that the fulvic acids contain organic free radicals as an internal part of their molecular structure. The concentration of unpaired electrons will increase by increasing the pH. The unpaired electron in fulvic acid interacts with the unpaired electron on copper(II) through the Π system, and this will decrease the spin concentration of fulvic acid complexed with copper(II). The displacement of titration curve from a free ligand (fructose-1,6-diphosphate, ribulose-1,5-diphosphate, phospherine, phosphothreonine, and 3-phosphoglyceric acid, to a ligand plus copper(II) (1:1 ratio) shows there is a strong interaction between copper(II) and the corresponding ligand. All complexes absorb UV-visible at …

The second order rate constants for nucleophilic substitution by methoxide of (Z)- and (E)-O-methylbenzohydroximoyl fluorides [C6H4C(F)=NOCH3] with various substituents on the phenyl ring [p-OCH3 (1h, 2h), p-CH3 (1g, 2g), p-Cl (1f, 2f), p-H (1e, 2e), (3,5)-bis-CF3 (1i, 2i)] in 90:10 DMSO:MeOH have been measured. A Hammett plot of these rate constants vs σ values gave positive ρ values of 2.95 (Z isomer) and 3.29 (E isomer). Comparison of these rates with methoxide substitution rates for Omethylbenzohydroximoyl bromide [C6H4C(Br)=NOCH3] and Omethylbenzohydroximoyl chloride [C6H4C(Cl)=NOCH3] reveal an element effect for the Z isomers of Br:Cl:F(1e) = 2.21:1.00:79.7 and for the E isomers of Cl:F(2e) = 1.00:18.3. With the p-OCH3-imidoyl halides the following element effects are found: Br:Cl:F(1h) = 2.78:1.00:73.1 for the Z isomer and Br:Cl:F(2h) = 1.97:1.00:12.1 for the E isomer. Measurement of activation parameters revealed ∆S≠ = -17 eu for 1e and ∆S≠ = -9.9 eu for 2e. Ab initio calculations (HF/6-31+G*, MP2/6-31+G*//HF/6-31+G*, B3LYP/6- 31+G*//HF/6-31+G*, HF-SCIPCM/6-31+G*//HF/6-31+G*) were performed to define the reaction surface. These calculations demonstrate a relatively large barrier for nucleophilic attack in relation to halogen loss and support the experimental findings that this reaction proceeds by an addition-elimination mechanism (AN# + DN). The imidoyl fluorides have been used to synthesize …

The unified learning model (ULM) focuses on students' engagement, motivation, prior knowledge, and working memory. This study employs the use of video games to assess students' learning through a 3D chemistry gaming environment. In this human-subjects research, students carried out missions and applied reasoning to solve problems appropriate for general chemistry content. For learning to occur, students must be engaged and motivated as stated in the ULM. Learning cannot necessarily be accomplished by experience alone, and critical thinking is required to turn the experience into learning. The interpretation of educational theory applied to video games and this proposed study are discussed. A moderately positive correlation was found between exam score and study time (playing the game). Essentially the more time spent playing the game or an online activity the higher the exam scores. There was an alpha level less than 0.05 (p < 0.05) between the experimental group and non-traditional group (no game or online activity). Supporting that there was a statistically significant difference between groups, the null hypothesis was accepted between the game and online activity. Furthermore, as stated under the ULM, engagement is necessary for optimal learning.

The purpose of this investigation was to study the syntheses of enol lactones and to prepare a series of amide derivatives of these compounds.

In model reaction systems to test amino acids in chlorinated waste effluents, several amino acids were chlorinated at high chlorine doses. (2000-4000 mg/1). Amino acids present in municipal waste effluents before and after chlorination were concentrated and purified using cation exchange and Chelex resins. After concentration and cleanup of the samples, the amino acids were derivatized by esterification of the acid functional groups and acylation of the amine groups. Identification and quantification of the amino acids and chlorination products was carried out by gas chromatography/mass spectrometry, using a digital computer data system. Analysis of the waste products revealed the presence of new carbon-chlorine bonded derivatives of the amino acid tyrosine when the effluents were treated with heavy doses of chlorine.

A study was conducted to investigate the relationships between cybergaming treatment groups and the control group (N = 99: ncontrol = 8; nlogic = 29; nspatial = 30; ncombination = 32) with success in the organic chemistry I course as measured by achievement over a 10-week period. The treatment groups included logic training, spatial training, and combination logic-spatial training. Students' ability was measured by pre/post exams using the Group Assessment of Logical Thinking (GALT) to measure logic ability, Purdue Visualizations of Rotations (ROT) test to measure spatial skills, and the General-Organic-Biochemistry (GOB) Exam to measure content attainment. Finally, students' responses about participation in this experience were evaluated using open- and closed-ended questions on a self-developed survey. A second study was conducted to evaluate the relationship between the cybergaming treatment and control groups (N = 88: nexperimental = 27; ncontrol = 61) with success in the general chemistry I course as measured by achievement and final course averages and grades. The cybergaming treatment group underwent intensive combination logic-spatial training for 10 weeks. Students' progress was measured using three pre/post instruments: Group Assessment of Logical Thinking (GALT) measured logic ability, Purdue Visualizations of Rotations (ROT) Test measured spatial skills, and the California …

The method utilizes both cation and anion concentrator columns in parallel as a preconcentration system. The preconcentrator system is loaded using a reagent delivery module operated for a specific time at a preset flow rate. Total injection volumes of 2-5 ml are routinely used. Various chromatograms are discussed along with detailed information concerning detection limits for sodium and chloride, the system operating conditions, and the solutions to other pitfalls which have arisen during the course of this work.

The determination of carbon monoxide is also possible by trapping CO on preconditioned molecular sieve and thermal desorption. Analysis in this case is performed by gas chromatography/mass spectroscopy, although the trapping technique is applicable to other suitable GC techniques.

Within this educational endeavor instrumental development was explored through the investigation of microwave induce stable electromagnetic waves within a non-linear yttrium iron garnet ferromagnetic waveguide. The resulting magnetostatic surface waves were investigated as a possible method of rapid analytical evaluation of material composition. Initial analytical results indicate that the interaction seen between wave and material electric and magnetic fields will allow phase coherence recovery andanalysis leading to enhancement of analytical value. The ferromagnetic waveguide selected for this research was a high quality monocrystalline YIG (yttrium iron garnet) film. Magnetostatic spin waves (MSW) were produced within the YIG thin waveguide. Spin waves with desired character were used to analytically scan materials within the liquid and solid phase.

The preparation of layered double hydroxides via co-precipitation of a divalent/trivalent metal solution against a base results in 1 mm LDH particles with a disorganized metal lattice. Research was performed to address these morphological issues using techniques such as Ostwald ripening and precipitation via aluminate. Another interesting issue in layered double hydroxide materials is the uptake and orientation of anions into the interlayer. Questions about iron cyanide interlayer anions have been posed. Fourier transform infared spectroscopy and powder x-ray diffraction have been used to investigate these topics. It was found that factors such as orientation, anion charge, and anion structure depended on the divalent/trivalent metal ratio of the hydroxide layer and reactivity time. The cyanide self-addition reaction is an important reaction of classical prebiotic chemistry. This reaction has been shown to give rise to amino acids, purines and pyrimidines. At cyanide concentrations similar to that expected on the early earth, hydrolysis to formamide rather than self-addition occurs. One theory to alleviate this side reaction is the use of minerals or clays that are thought to concentrate and catalyze prebiotics of interest. Layered double hydroxides have been studied as a catalyst for this reaction.

The specific goal of the investigation was the measurement, as a function of temperature, of the self-diffusion coefficients of Pb210 and Cl36 in PbCl2-KCl compositions in the region of the first compound, and to calculate from these data the activation energy necessary for the diffusion of these ions.

Investigations presented here are (a) the study of reorientational dynamics and internal rotation in transition metal complexes by NMR relaxation experiments, and (b) the study of ligand exchange dynamics in transition metal complexes by exchange NMR experiments. The phenyl ring rotation in Ru3(CO)9(μ3-CO)(μ3-NPh) and Re(Co)2(CO)10(μ3- CPh) was monitored by 13C NMR relaxation experiments to probe intramolecular electronic and/or steric interactions. It was found that the rotation is relatively free in the first complex, but is restrained in the second one. The steric interactions in the complexes were ascertained by the measurement of the closest approach intramolecular distances. The rotational energy barriers in the two complexes were also calculated by using both the Extended Hiickel and Fenske-Hall methods. The study suggests that the barrier is due mainly to the steric interactions. The exchange NMR study revealed two carbonyl exchange processes in both Ru3(CO)9(μ3-CO)(μ3-NPh) and Ru3(CO)8(PPh3)(μ3-CO)(μ3-NPh). The lower energy process is a tripodal rotation of the terminal carbonyls. The higher energy process, resulting in the exchange between the equatorial and bridging carbonyls, but not between the axial and bridging carbonyls, involves the concerted formation of edge-bridging μ2-CO moieties. The effect of the PPh3 ligand on the carbonyl exchange rates has been discussed. …

Reductive functionalization of methyl ligands by 3d metal catalysts and two possible side reactions has been studied. Selective oxidation of methane, which is the primary component of natural gas, to methanol (a more easily transportable liquid) using organometallic catalysis, has become more important due to the abundance of domestic natural gas. In this regard, reductive functionalization (RF) of methyl ligands in [M(diimine)2(CH3)(Cl)] (M: VII (d3) through CuII (d9)) complexes, has been studied computationally using density functional techniques. A SN2 mechanism for the nucleophilic attack of hydroxide on the metal-methyl bond, resulting in the formation of methanol, was studied. Similar highly exergonic pathways with very low energy SN2 barriers were observed for the proposed RF mechanism for all complexes studied. To modulate RF pathways closer to thermoneutral for catalytic purposes, a future challenge, paradoxically, requires finding a way to strengthen the metal-methyl bond. Furthermore, DFT calculations suggest that for 3d metals, ligand properties will be of greater importance than metal identity in isolating suitable catalysts for alkane hydroxylation in which reductive functionalization is used to form the C—O bond. Two possible competitive reactions for RF of metal-methyl complexes were studied to understand the factors that lower the selectivity of C—O bond …

Computational techniques, mostly density functional theory (DFT), were applied to study metal-based catalytic processes for energy conversion reactions. In the first and second projects, the main focus was on activation of the light alkanes such as methane, which have thermodynamically strong and kinetically inert C–H bonds plus very low acidity/basicity. Two Mo-oxo complexes with the different redox non-innocent supporting ligands, diamide-diimine and ethylene-dithiolate, were modeled. These Mo-oxo complexes are modeled inspired by active species of a metalloenzyme, ethylbenzene dehydrogenase (EBDH). The results for the activation of the benzylic C–H bond of a series of substituted toluenes by modeled Mo-oxo complexes show there is a substantial protic character in the transition state which was further supported by the preference for [2+2] addition over HAA for most complexes. Hence, it was hypothesized that C–H activation by these EBDH mimics is controlled more by the pKa than by the bond dissociation free energy of the C–H bond being activated. The results suggest, therefore, promising pathways for designing more efficient and selective catalysts for hydrocarbon oxidation based on EBDH active site mimics. Also, it is found that the impact of supporting ligand and Brønsted/Lowry acid/base conjugate is significant on the free energy barrier of …

Environmental monitoring is becoming increasingly important, primarily in urban areas due to the concentrated levels of human activities. The air sampling device presented is a novel method to sample air which harnesses the power of paper spray ionization paired with the intrinsic advantages of mass spectrometry such as high sensitivity, high selectivity, high throughput, and the ability to monitor multiple compounds at once.

Podcasts covering essential first-semester general chemistry laboratory techniques and central concepts that aid in experimental design or data processing were prepared and made available for students to access on an as-needed basis on iPhones- or iPod touches-. Research focused in three areas: the extent of podcast usage, the numbers and types of interactions between instructors and research teams, and student performance on graded assignments. Data analysis indicates that the podcast treatment research teams accessed a podcast 2.86 times on average during each week that podcasts were available. Comparison of interaction data for the lecture treatment research teams and podcast treatment research teams reveals that interactions with instructors were statistically significantly fewer for teams that had podcast access rather than a pre&#8208;laboratory lecture. The implication of the results is that student research teams were able to gather laboratory information more effectively when it was presented in an on-demand podcast format. Finally, statistical analysis of data on student performance on graded assignments indicates no significant differences between outcome measures for the treatment groups when compared as cohorts. The only statistically significant difference is between students judged to be highly motivated; for this sub&#8208;group the students in the podcast treatment group earned a …

The field of direct inject mass spectrometry includes a massive host of ambient ionization techniques that are especially useful for forensic analysts. Whether the sample is trace amounts of drugs or explosives or bulk amounts of synthetic drugs from a clandestine laboratory, the analysis of forensic evidence requires minimal sample preparation, evidence preservation, and high sensitivity. Direct inject mass spectrometry techniques can rarely provide all of these. Direct analyte-probed nanoextraction coupled to nanospray ionization mass spectrometry, however, is certainly capable of achieving these goals. As a multifaceted tool developed in the Verbeck laboratory, many forensic applications have since been investigated (trace drug and explosives analysis). Direct inject mass spectrometry can also be easily coupled to assays to obtain additional information about the analytes in question. By performing a parallel artificial membrane assay or a cell membrane stationary phase extraction prior to direct infusion of the sample, membrane permeability data and receptor activity data can be obtained in addition to the mass spectral data that was already being collected. This is particularly useful for characterizing illicit drugs and their analogues for a biologically relevant way to schedule new psychoactive substances.

Mother nature has laid out a beautiful blueprint to capture sunlight and convert to usable form of energy. Inspired by nature, donor-acceptor systems are predominantly studied for their light harvesting applications. This dissertation explores new donor-acceptor systems by studying their photochemical properties useful in building artificial photosynthetic systems. The systems studied are divided into phthalocyanine-porphyrin-fullerene-based, perylenediimide-based, and aluminum porphyrin-based donor-acceptor systems. Further effect of solvents in determining the energy or electron transfer was studied in chapter 6. Such complex photosynthetic analogues are designed and characterized using UV-vis, fluorescence spectroscopy, differential pulse voltammetry and cyclic voltammetry. Using ultrafast transient absorption spectroscopy, the excited state properties are explored. The information obtained from the current study is critical in getting one step closer to building affordable and sustainable solar energy harvesting devices which could easily unravel the current energy demands.

Donor-acceptor systems have unique properties that make them ideal candidates for solar energy harvesting through mimicry of natural photosynthesis. This dissertation is focused on unraveling those unique properties in various types of donor-acceptor systems. The systems investigated are categorized as closely linked, push-pull, supramolecular, and multi-unit. As part of the study, photosynthetic analogues based on BF2-chelated dipyrromethene (BODIPY), porphyrin, phthalocyanine, truxene, ferrocene, quinone, phenothiazine (PTZ), perylenediimide (PDI), fullerene (C60), dicyanoquinodimethane (DCNQ), tetracyanobutadiene (TCBD), and triphenylamine (TPA) are investigated. The effects of proximity between donor-acceptor entities, their geometrical orientation relative to each other, push-pull character of substituents, and competitive energy and electron transfer are examined. In all systems, primary events of photosynthesis are observed, that is absorption and energy transfer and/or electron transfer is witnessed. Ultrafast transient absorption spectroscopy is utilized to characterize the photo-induced events, while other methods such as steady-state luminescence, cyclic voltammetry, differential pulse voltammetry, chronoamperometry, and computational calculations are used to aid in the characterization of the donor-acceptor systems, in particular their applicability as solar energy harvesters.