Chemistry and chemical engineering.
Vice-chair: Mudlagiri Goli, Mississippi Valley State University
Exhibit Hall A1
8:30 PREPARATION OF HOMOCHIRALLY SIMILAR SERINE ANALOGS FROM A COMMON INTERMEDIATE
Dale Rosado* and Douglas S. Masterson, University of Southern Mississippi, Hattiesburg, MS 39406
Recently, there has been much research in the area of unnatural ([beta], [gamma], and [delta]) amino acids. It has been shown that incorporation of such unnatural amino acids into protease specific sites in small peptides (such as peptide hormones) increases the in vivo half life of the peptide. This behavior could make such peptides powerful site specific drug delivery systems to cells, such as cancerous cells, which produce and use relatively large quantities of peptide hormones composed of natural ([alpha]) amino acids. Currently, synthetic routes to synthesize the unnatural analogs of the [alpha]-amino acids easily, inexpensively, and with sufficient enantiomeric yields does not exist. The goal of this project is to develop a method to synthesize the unnatural serine analogs via a common synthetic intermediate. Furthermore, the synthetic path chosen allows for synthesis of both enantiomers in sufficient chemical and enantiomeric yields. This synthetic path uses derivatized prochiral malonate diesters (Diethyl-2-[(benzyloxy)methyl]-2-methyl malonate), on which a desymmetrization enzyme (i.e. Esterases) can be used to hydrolyze one of the ester substituents to a carboxylic acid. This produces a chiral propanoic acid derivative with an enantiomeric excess of either the R or S enantiomer. The acid substituent can then be derivatized via combination of several well-known synthetic paths (Curtius, Wolff, Witting), to give the unnatural serine analogs.
8:45 PHOTO-INDUCED POLYMERIZATION OF IONIC LIQUID MONOMERS
Zulma Jimenez (1*), John A. Pojman (1), Hui Zhou (1), Charles Hoyle(1), Andrew B. Lowe (1), and Mark Paley (2), (1) University of Southern Mississippi, Hattiesburg, MS, 39406 and (2) A-Z Technology, Marshall Space Flight Center XD42, Huntsville, AL 35812
Real Time FTIR was used to measure the maximum photo-polymerization rates of tributylmethylammonium acrylate, methacrylate and (2-methacrylate)ethyl phosphate, which are novel ionic liquid monomers. These were compared with the rates for the component acids at 25 and 80[degrees]C.
9:00 COMPARISION OF THE CORROSION EFFECT UPON WIRES AND PIPES UTILIZED IN SHIPBUILDING
Matt Sword (1*) Steven Manis (1), and Ulises B. Chavez (2), (1) Mississippi Gulf Coast Community College, Gautier, MS 39533, National Aeronautics and Space Administration, Stennis Space Center, MS 39522 and (2) Northrop Grumman, Pascagoula, MS 39581
Northrop Grumman is one of the largest shipbuilders in the country and continues to deal with corrosion and conductivity of wires and cables used in ship construction. Cable and wire were stored at various locations on ships in preparation for installation when Hurricane Katrina flooded the shipyard. This resulted in over 5,000 reels of cable and electric wire being exposed to salt water for several days in varying degrees. Cable must pass certain manufacturer quality control requirements, i.e., chlorides not greater than 100ppm. The testing for this requirement is outlined in Naval Testing Protocol. The Pascagoula Northrop Grumman staff is testing the rolls of cable to see what rolls can be saved or must be discarded. Northrop Grumman and the cable manufacturers supervised all testing to insure consistency, standardization, and test techniques.
9:15 AMIDE AND THIOAMIDE BASED RECEPTORS FOR ANIONS
Md. Alamgir Hossain, Jackson State University, Jackson, MS 39217
Design and synthesis of neutral receptors for anions are of current intense interest from the view of their sophisticated application in both environment and medicine. Amide based synthetic receptors provide necessary binding sites for anions through acidic NH groups. Because such receptors are soluble in organic solvent, therefore they could be useful in the application oriented field for separation and removal of anions of environmental relevance. We devised macrocyclic receptors containing four amido groups that show very strong affinity for both sulfate and phosphate. We also converted the macrocyclic amides to macrocyclic thioamides to increase the acidity of NH groups. Studies indicated that thioamide based macrocycles show superior binding affinity for anions. The details of the synthesis of new receptors, NMR binding studies and crystallographic structures will be presented.
9:30 A NOVEL METHOD TO SYNTHESIZE UNNATURAL CYSTEIN ANALOG
Kinkini Roy and Douglas S. Masterson*, University of Southern Mississippi, Hattiesburg, MS 39406
The aim of this project is to synthesize a wide variety of unnatural cystein analogs (alpha, beta, gamma, delta) from a common synthetic intermediate. This should allow for the construction of amino acids in optically pure form and for the parallel preparation of both enantiomers. The general approach will be as follows: 1) preparation of the prochiral intermediates of malonic acid by using tert-Butylchloromethylsulfide 2) Using esterase to perform a desymmetrization of the prochiral intermediates 3) Analysis of the resulting chiral half ester intermediates 4) Formation of different amino acids: [alpha] (Curtius), [beta] (Wolff, Curtius), [gamma] (Wittig, Curtius), [delta] (Wolff, Wittig, Curtius) from that half ester. Once the synthesis has been achieved we can use that to prepare unnatural peptides with potential biological or enhanced biological activity.
9:45 DESIGN OF A PHOTOACTIVATED DNA-CLEAVING AGENT
Wolfgang H. Kramer*, B. Woods Curry, David T. Cutter, and Tiffany R. Hammond, Millsaps College, Jackson, MS 39210
The design of a photoactivated DNA-cleaving reagent has to combine the actual cleaving functionality and the DNA-binding properties in the same molecule. We used a fragmentable N-O bond as the cleaving functionality that produces an alkoxy radical and an heteroaromatic radical cation. Intercalators such as ethidium bromide have been widely used to bind to DNA but the actual binding properties of a variety of synthesized derivatives have been poor. Pyrrolo-[1,4]-benzodiazepines are groove-binders that require exact stereochemistry to have optimal binding properties. The synthesis of pyrrolo-[1,4]-benzodiazepines involves an interesting photochemical cyclization step that shows a remarkable memory of chirality effect via a 1,7-triplet biradical. This control of the stereochemistry enables the design of optimized pyrrolo-[1,4]-benzodiazepines where the cleaving functionality can be added.
10:15 AQUEOUS ACYCLIC DIENE METATHESIS (ADMET) AS A NEW SYNTHETIC APPROACH FOR WATER-SOLUBLE MATERIALS WITH ANTIMICROBIAL ACTIVITY
Curtis Coumbe*, and Hans J. Schanz, University of Southern Mississippi, Hattiesburg, MS 39406
Water-soluble polymers with antimicrobial properties possess a broad application spectrum and the use of Acyclic Diene Metathesis (ADMET) as synthetic technique for these materials has yet to be explored. ADMET has to offer several advantages over other polymerization methods, namely straightforward monomer synthesis, thermodynamically driven polycondensation kinetics, in ideal cases living character (lack of abortion mechanisms), and a high versatility and reactivity towards structurally very different substrates. Quaternary Ammonium Compounds (QAC's) are some of the most commonly used antimicrobials. Common polymeric materials bear positively charged ammonium groups as functional part of the side chains of a polymeric (usually polyacrylate) spine. In our investigations, we target the synthesis of diallyl or dipropenyldiammonium and diimidazolium salt monomers. Upon ADMET polymerization these monomers will be converted into linear polymeric materials incorporating the functional positively charged into the chain. In this presentation, we will discuss catalyst designs, synthetic concepts and initial results of our investigations.
10:30 PREPARATION OF HOMOCHIRALLY SIMILAR LYSINE ANALOGS FROM A COMMON INTERMEDIATE
Jessie Geoghegan and Douglas S. Masterson*, University of Southern Mississippi, Hattiesburg, MS 39406
The objective of this project is to develop a way to synthesize unnatural analogs of the amino acid, Lysine, from a common intermediate. The ultimate goal is to use these Lysine analogs to make small peptides which may potentially aid in cancer treatment. The unnatural amino acid analogs can be substituted into peptides in the place of the natural amino acids. It has been shown that the peptides with the unnatural analogs have a longer half life in serum than the peptides with the natural amino acids. These peptides may potentially be used to specifically deliver drugs to cancer cells. Diethyl methyl malonate is used as the staring material. N-(4-Bromobutyl)-phthalimide is then introduced as a protective side chain. This gives a prochiral diester. One of the ester groups is then hydrolyzed to a carboxylic acid to obtain a chiral ester/ acid. From this, the enantiomeric excess can be determined. Several paths can then be used to convert the acid to unnatural [alpha], [beta], [gamma], and [delta] amino acids. These paths include those of Curtius, Wolff, and Witting.
10:45 ANALYSIS OF WOMBAT GASES INJECTED INTO AND ABSORBED BY SCRUBBING SOLUTIONS
Veronika Viner* and David L. Wertz, University of Southern Mississippi, Hattiesburg, MS 39406
Scrap tires filling landfills is a worldwide environmental problem and continues to grow every day. Although the rubber from these tires can be converted into useful low-grade rubber products or combined with asphalt to make roads, the rubber portion that still contains large amounts of steel is a problem and not easily recyclable because of the steel imbedded in it. The WOMBAT method is a viable process for converting high-steel tire chips into WOMBAT powder and other useful products. The gases synthesized from the process are passed through a series of scrubbing solutions (aqueous KOH and water) and converted into potassium nitrate, a good fertilizer. FTIR was used to determine which gases were injected into but not absorbed by the scrubbing solutions. The spent KOH solution was evaporated until only crystals remained, and then WDXRD (Wavelength Dispersive X-ray Diffraction) and XRF (X-ray Fluorescence) were done to determine what the crystals were and what metal impurities they might contain. To quantify how much gas was actually being absorbed by the first scrubbing solution, the change in pH of the first scrubbing solution was measured and the solution was backtitrated to ~7 to determine the number of acidifying gas absorbed.
11:00 ASYMMETRIC CHROMIUM MEDIATED EPOXIDATION: A DETAILED INVESTIGATION USING MANUAL PARALLEL REACTION TECHNIQUES
Hans J. Schanz, University of Southern Mississippi, Hattiesburg, MS 39406
The asymmetric epoxidation of electron-rich olefins with chiral salen manganese and chromium complexes has been investigated thoroughly over the last decade. Despite many similarities between Cr and Mn-assisted epoxidation reactions such as structure and oxidation state of the active species, there are distinct differences in their spin states which result in different substrate selectivity for both metals. Most notably, the reactive oxo-Cr(V) species can be isolated and used as a reagent in a stoichiometric epoxidation reaction. In our investigations, we have employed parallel reaction techniques to determine the influence of various parameters (temperature, concentration of substrate, additive and catalyst) on product yield and enantiomeric excess for the catalytic and stoichiometric epoxidation of cis-[beta]-methylstyrene. We have established important dependencies between catalyst performance and these parameters for one catalyst and based on these results, we suggest an expansion of the formulated epoxidation mechanism.
11:15 ELECTROGENERATED CHEMILUMINESCENCE OF BENZOPHENONE USING BENZOPEROXIDE AS THE COREACTANT
Wujian Miao, University of Southern Mississippi, Hattiesburg, MS 39406
Electrogenerated chemiluminescence (ECL) is a process of light generation by electrode reactions. ECL produced from electrochemically oxidized and reduced species is called "annihilation ECL", while "coreactant ECL" is produced from the interactions between electrochemically reduced or oxidized luminophore and a strongly oxidizing or reducing intermediate formed after the chemical decomposition of an electrochemically reduced or oxidized coreactant. We report here the coreactant ECL of benzophenone (BP) using benzoperoxide (BPO) as the coreactant. In acetonitrile (MeCN) containing 0.10 M tetrabutylammonium perchlorate (TBAP), BP displayed a reversible redox process with a half potential value of ~-2.1 V vs Ag/[Ag.sup.+] (10 mM) at a Pt electrode. Under the same experimental conditions, a broad irreversible reduction wave with a peak potential of ~-1.1 V vs. Ag/[Ag.sup.+] was observed. Coreactant ECL of BP was obtained when a mixed BP and BPO MeCN solution was scanned between 0 and -3.0 V vs Ag/[Ag.sup.+] at a Pt electrode. The ECL appeared immediately after BP reduction. Potential pulsing between 0 and -3.0 V vs Ag/[Ag.sup.+] with a pulse period of 2 s was used to continuously generate the ECL so that the ECL spectrum centered at ~590 nm can be recorded with a CCD camera at -101 [degrees]C. In contrast, when the reaction medium was changed from MeCN to dichloromethane (DCM), only an irreversible reduction of BP at ~-2.1 V vs Ag/[Ag.sup.+] was observed, although no significant change in cyclic voltammetry was found for BPO. Coreactant ECL of BP-BPO in DCM was observed but the light intensity was 3~4 times less than that obtained from MeCN. In addition, the ECL spectrum peak was shifted from ~590 nm in MeCN to ~630 nm in DCM. The relevant ECL mechanism will be proposed.
11:30 SOIL ANALYSIS OF LAND AFFECTED BY A CHEMICAL SPILL
Jennifer Ford (1*), Paul Wallace (1*), Steven Manis (1), and Mark Woodrey (2), (1) Mississippi Gulf Coast Community College, Gautier, MS 39553, National Aeronautics and Space Administration, Stennis Space Center, MS 39522, and (2) Grand Bay National Estuarine Research Reserve, Moss Point, MS 39562
This project compared the soils of two designated sites on the Grand Bay National Estuarine Research Reserve. The first site was affected by a chemical spill from Mississippi Phosphates; the second site remained under normal conditions, with no chemical damage. The second site was used for comparison purposes. Phosphates and acidity are of interest as certain low pH levels prevent the soil from bonding with aluminum causing free radicals that kill biota. The extent of the soil damage was not analyzed prior to this investigation. The damage to the plant life was extensive indicating the contaminants were present, but the levels were unknown. This project will aide in the determination of the damage resulting from the spill and possibly help in the recovery process.
11:45 Divisional Business Meeting
Exhibit Hall A1
1:30 EVOLUTION OF TRANSIENT INTERFACIAL PHENOMENA IN MISCIBLE AND PARTIALLY MISCIBLE SYSTEMS
Gloria Viner* and John A. Pojman, University of Southern Mississippi, Hattiesburg, MS 39406
This study focused on the unusual interfacial phenomena of two different systems: IBA(isobutyric acid)/water and butanol/water. For this research project, how barodiffusion, temperature, and initial concentration affected these systems' diffusion process and interfacial tension are examined. Two different techniques to study interface dynamics were used: Laser Line Deflection (LLD) and Spinning Drop Tensiometer (SDT). Laser Line Deflection is a method in which a laser is used to measure diffusion coefficients via large concentration gradients and refractive index gradient at 1 g's. Spinning Drop Tensiometer is a method that involves interfacial tension measured at 50 g's. From these two methods, different behaviors were observed for IBA/water and butanol/water: IBA/water, in both LLD and SDT, had the aqueous phase "eating" the acidic phase while the butanol/water, for LLD, had the organic phase "eating" the aqueous, but, for SDT, the butanol/water's aqueous phase "ate" the organic phase. Despite some different behaviors for IBA/water and butanol/water, similar behaviors, such as sharp transition zones, were also observed.
1:45 X-RAY DIFFRACTION ANALYSIS OF SOIL FOR CLAY-MINERAL IDENTIFICATION
Patrick Heidingsfelder*, Patricia Villalta, and David L. Wertz, University of Southern Mississippi, Hattiesburg, MS 39406
Clay minerals have been identified in order to determine the viability of construction in specific areas. The presence of water-swelling clay minerals could have a negative impact on the structural integrity of the resulting structures. Clay fractions were separated from the bulk soil samples using a dispersing agent. The upper portion of this suspension was then collected in order to obtain the clays of the sample. The resulting slurry was then mounted on microscope slides. The clay particles were mounted as oriented aggregate mounts to force all particles to become linear. This packing was done for greater intensity of peaks when analyzed using X-ray diffraction. This must be done due to the random orientation of clays in nature. The XRD peak's were compared to known values to determine the composition of the clays.
2:00 RIBOFLAVIN-SENSITIZED PHOTOTRANS-FORMATION OF BENZO[A]PYRENE
Xueheng Zhao*, Huey-Min Hwang, and Xiaoke Hu, Jackson State University, Jackson, MS 39217
Riboflavin (Vitamin B2) is a natural dye-sensitizer habitually present in natural waters. Effects of riboflavin as photosensitizer on the transformation of benzo[a]pyrene (BaP) in the aqueous-organic solvent (water/actonitrile/methanol 50/40/10) were investigated in this study. We hypothesized that the behavior of BaP in the solvent was similar to that in water. The photolysis half-life of BaP (10 [micro]M) in solution containing 50 [micro]M riboflavin was 5 min, compared to 98 min in the absence of riboflavin. The rate of phototransformation of BaP increased as the concentration of riboflavin was raised from 10 [micro]M to 100 [micro]M under both natural sunlight and UVA irradiation. The half-life of BaP in the presence of 50 [micro]M riboflavin was 10.6 min and 43.1 min when exposed to visible range of natural sunlight and UVA irradiation respectively. Riboflavin decomposes under natural sunlight. Lumichrome, a principal photoproduct of riboflavin, was shown to photosensitize BaP under natural sunlight after photolysis of riboflavin. Our study indicated that other photoproducts from riboflavin, such as lumiflavin, were also involved in the phototransformation of BaP under sunlight when riboflavin diminished. The major photoproducts in the photolysis of BaP were determined as 1,6-benzo[a]pyrene-dione, 3,6-benzo[a]pyrene-dione, 6,12-benzo[a]pyrene-dione by using high performance liquid chromatography (HPLC). All these products were detected in the samples which were irradiated under different light sources and in the presence or absence of riboflavin. The possible phototransformation mechanism will be discussed. [supported by NIH-SCORE S06GM08047 (to JSU) and U.S. Department of the Army # DAAD 19-01-1-0733 and # W911NF-04-1-0327 to JSU].
2:15 DETERMINING THE INTERFACIAL TENSION USING A SPINNING DROP TENSIOMETER
Elizabeth Parker* and John A. Pojman, University of Southern Mississippi, Hattiesburg, MS 39406
The interfacial tension of the isobutyric acid and water system was determined by using a spinning drop tensiometer (SDT). SDT utilizes high rotation speeds to measure the interfacial tension between a small drop of a light phase and a surrounding heavier phase. The specific method known as end-pinching was used to analyze the system. The end-pinching phenomenon occurs when the speed of rotation in the capillary is suddenly decreased. This reduction of rotational speed causes the drop to retract and breakup into smaller drops. The effective interfacial tension was determined by using the beginning and final drop size and the rate of retraction.
2:30 GRUBBS-TYPE METATHESIS CATALYSTS WITH FUNCTIONALIZED CARBENES FOR APPLICATIONS IN AQUEOUS MEDIA
Adam Roberts* and Hans J. Schanz, University of Southern Mississippi, Hattiesburg, MS 39406
The true potential of aqueous metathesis, i.e. its scope and limitations, has yet to be explored. The concept, while proven to be feasible for certain ruthenium (Ru)-based Grubbs-type catalysts, we find that water-soluble examples of such catalysts with an excellent performance profile remain elusive. This project targets the synthesis of novel Ru-based metathesis catalysts which bear functionalized carbene moieties which should enhance catalyst solubility in aqueous solvents. Therefore, we will exchange the initial carbene of highly active metathesis catalysts using functional olefins. For our investigations, we synthesize highly metathesis-active Ru-catalysts as reactive precursors for our investigations. Metathesis reactions are predominantly thermodynamically driven and mechanistically represent a series of carbene exchange reactions. Carbene exchange with functionalized, monosubstituted olefins should afford catalysts with functionalized carbenes which ideally provide sufficient catalyst solubility in aqueous media. In our investigations, we determine catalyst activity and stability for aqueous ring opening metathesis polymerization (ROMP) reactions of water-soluble norbornene derivatives.
2:45 PHOTOCHEMICAL SYNTHESIS OF PYRROLO-[1,4]-BENZODIAZEPINES
David T. Cutter*, B. Woods Curry, Tiffany R. Hammond, and Wolfgang H. Kramer, Millsaps College, Jackson, MS 39210
Pyrrolo-[1,4]-benzodiazepines have been shown to be efficient DNA groove-binding reagents. Photochemically synthesized pyrrolo-[1,4]-benzodiazepines exhibit a remarkable Memory of Chirality effect over the course of the photochemical cyclization step. This control of the stereochemistry allows the design of novel pyrrolo-[1,4]-benzodiazepines with the use of the cheap building block anthranilic acid. Aromatic imides serve as chromophors and are introduced in the first step of the synthesis. Coupling with [alpha]-acids out of the chiral pool is adding a chiral element to the photochemical precursor which is then cyclized in the decarboxylative photocyclization.
3:00 MONITORING ISOTHERMAL FRONTAL POLYMERIZATION IN THIN-LAYERED CELLS VIA LASER LINE DEFLECTION
Chip Fillingane* and John A. Pojman, University of Southern Mississippi, Hattiesburg, MS 39406
The purpose of this research is to develop a method of monitoring fronts in isothermal frontal polymerization in a sample with minimal width using laser line deflection. As a part of this research a thin-layered cell is being developed, as well as a methods of increasing the resolution of laser line deflection. The thin-layered cell is being developed is designed to be inexpensive, in order to reduce costs incurred from the breakage of the cuvettes currently used. Lastly, the methods of analysis involved have been automated. This will open up opportunities to observes more systems, as well as systems where minimal quantities of material must be used due to expense.
6:00 Divisional Poster Session--Exhibit Hall B
MECHANISTIC ENZYMOLOGY OF 3-HYDROXY-ANTHRANILATE-3,4-DIOXYGENASE (HAD)
Amanda Mims (1*), Antionette Walker (2), and Aimin Liu (2), (1) Tougaloo College, Tougaloo, MS 39174 and (2) University of Mississippi Medical Center, Jackson, MS 39216
A key enzyme in tryptophan catabolism is 3-hydroxy-anthranilate-3,4-dioxygenase of HAD. Within tryptophan catabolism, the kynurenine pathway works to form quinolinic acid (QUIN). Quinolinic acid is effective in producing neuron excitation in the central nervous system. Excessive levels of QUIN have been shown in patients with AIDS dementia, depression, Huntington's disease, and Alzheimer's. HAD is the last enzyme in the pathway. This enzyme utilizes a non-heme Fe and dioxygen to convert 3-hydroxyanthranilic acid (3-HAA) to 2-amino-3-carboxymuconate-6-semialdehyde (ACMS). These steps create QUIN non-enzymatically. In the past, several inhibitors have been used to reduce the activity or the formation of quinoline. Two specific inhibitors are 2-aminophenol and 3-ASA. Using a 20 micromolar concentration of each, the inhibitors were tested on two mutants of HAD, I142A and D49A, along with 1 microliter of a Fe solution and a 20 micromolar solution of 3-HAA. There were positive effects resulting in the further study of the inhibition of the enzyme. This research was supported by Mississippi Functional Genomics Network.
EVALUATION OF TECHNIQUES FOR DRYING AMORPHOUS PRECIPITATED SILICA
Cardell Givens* and Charles Smithhart, Delta State University, Cleveland, MS 38733
Synthetic amorphous precipitated silicas are used in many areas including free-flow additives for food, flatting agents in paint formulations, and fillers for tire and rubber applications. This material is often prepared by HC1 or H2SO4 acid addition to aqueous sodium silicate solutions. As such, the silica requires some form of drying treatment before use. Commercial silicas contain up to 10% residual water even after drying. Though considered a non-hazardous nuisance dust, amorphous precipitated silica can be transformed through traditional convective/conductive heating into crystalline forms such as cristobalite that are known respiratory hazards. This study compares the effects on crystallinity and ignition loss when a commercial amorphous precipitated silica is heated using both a conventional convection/conduction muffle furnace and a microwave oven. The results indicate that microwave drying may offer a comparable drying method that does not induce crystallinity.
SYNTHESIS AND CHARACTERIZATION OF DIORGANO TIN COMPLEX OF ACETONE 4-ETHYL -3-THIOSEMICARBAZONE
Lungile Sitole (1), Ramaiyer Venkatraman (1*), Razaq Sweise (2), and Bohari M. Yamin (2), (1) Jackson State University, Jackson MS 39217 and (2) Universiti Kebangsaan, 43600, Bangi, Selangor, Malaysia
The reaction between 4N ethyl-3-thiosemicarbazide, Hetsc and diphenyl tin(IV) dichloride, Sn(C6H5)2C12 a yielded crystalline compound, [Sn(C5H5)2(eptsc)C1]. Single crystal study of this compound revealed to be a monoclinic crystal system (space group P2(1)/n with a = 8.2500(12), b = 20.617(3), c = 12.5839(18) [Angstram], V = 2039.4(5)[Angstram]3 and Z = 4). The monomeric form of the complex has a five-member chelated ring structure with distorted trigonal bipyramidal (TBP) geometry. The two phenyl-carbon atoms and the sulfur atom are located at the equatorial position whereas the chlorine and the azomethine nitrogen atoms are present at the axial position. Elemental analysis, IR, proton NMR spectroscopy and electrical conductivity methods were used to characterize these complexes. The molar conductivity value of the complex suggests the existence of a 1:1 nonionic type of the complex.
THE SCOPE AND PRINCIPLES OF GREEN CHEMISTRY
Anil K. Sharma* and Shanise Brown, Mississippi Valley State University, Itta Bena, MS 38941
Chemistry is used in all walks of life. It is used in the production of all man-made materials from medicines to cleaning products. While these products seem to make life easier, the truth is that they may be more harmful than helpful. When some chemicals are made, more wasteful products are produced than useful. This results in money being lost through finding ways to get rid of or treat the waste. The waste could enter bodies of water or the air causing serious damage to organisms. Chemical substances were not looked at as a threat until the years around 1960. In later years several command and control laws were instituted. These laws deal with correcting the problem after it has occurred. Green Chemistry's purpose is to prevent the pollution problem before it starts. Green Chemistry is defined as "the utilization of a set of principles that reduces or eliminates the use or generation of hazardous substances in the design, manufacture, and application of chemical products." There are twelve principles of Green Chemistry and they are: prevention, atom economy, less hazardous chemical synthesis, designing safer chemicals, safer solvents and auxiliaries, design for energy efficiency, use of renewable feed stocks, reduce derivatives, catalysis, design for degradation, real time analysis for pollution prevention, and inherently safer chemistry for accident prevention. These twelve principles give the whole scope of Green Chemistry. Today Green Chemistry is being explored constantly. The world could be a cleaner and much safer place if Green Chemistry techniques were put into play for all actions everywhere.
THIOLATED POLYMERS (THIOMERS), NEW POTENTIAL MUCOADHESIVE DRUG DELIVERY VEHICLES?
Xiao Deng*, Andrew B. Lowe, and Robert C. Bateman, Jr., University of Southern Mississippi, Hattiesburg, MS, 39406
The purpose of the present study was to investigate the possibility and the benefit of thiolated polymers (thiomers) as new potential mucoadhesive drug delivery vehicles which facilitate and enhance the absorption and thus bioavailability of orally-administered therapeutics. We tried two kinds of thiomers. (1) Covalently bound L-cysteine to poly (acrylic acid). (2) Covalently bound L-cysteine to poly (4-vinylbenzyl chloride). A very low concentration of dBBr could label some of the thiol groups, while the thiomer still had lots of free thiol groups which could conjugate with hydrophobic drug. The next step is to conjugate hydrophobic drug with the thiomers, then check their mucoadhesive properties. We expect to find much improved cohesiveness which is attributing to the formation of intermolecular covalent disulfide bonds between the free thiol functional groups on the thiomers. Such improved cohesiveness is a desirable feature since it reduces presystemic degraduation (smaller exposed surface area of delivery vehicle), prolongs drug release, and improves patient compliance.
ELECTROCHEMICAL SYNTHESIS AND PHOTOCONDUCTIVITY STUDIES OF POLY(N-VINYL CARBAZOLE)
Houssam Hajj Houssein, Delta State University, Cleveland, MS 38733
The green-colored conducting forms of poly(n-vinyl carbazole) (PVK) have well known photoconductive properties in the ultraviolet region of the EM spectrum. This study examines the electrochemical synthesis of PVK films doped with HS[O.sup.4-] and N[O.sup.3-]. Experimental variables included the use of ethanol and dichloromethane solvents under various conditions of monomer/dopant concentration, several electrode materials and geometries, and different voltage/current parameters. Photoconductivity response in the x-ray spectral region (1.5 [Angstrom]) was also measured.
PREPARATION AND STRUCTURAL STUDIES ON THE DIORGANOTIN (IV) COMPLEXES WITH THIOSEMICARBAZONES OF CYCLOPENTANONE
Ramaiyer Venkatraman* and Alicia M. Beatty, Jackson State University, Jackson, MS 39217 and Mississippi State University, Mississippi State, MS 39762
The reaction of SnPh2C12 with cyclopentanone-3-thiosemicarbazone (HCptsc), and cyclopentanone-4-ethyl-3-thiosemicabazone (HCpetsc) in methanol yielded the formation of penta-coordinated complexes Sn(Cptsc)Ph2Cl (1)and Sn(Cpetsc)Ph2Cl(2) respectively. The complexes were characterized by microanalysis, conductivity, IR and NMR spectroscopic methods. The X-ray diffraction study revealed that the complexes possess a trigonal bipyramidal geometry and crystallizes in the monoclinic crystal system, space group P21/c, with (1) a = 8.5509(14), b = 14.092(2), c = 16.371(3) [Angstrom], beta = 100.176(3)o, V = 1941.8(6) [Angstrom]3 and Z = 4, and (2) a = 9.0459(14), b = 22.922(4), c = 11.3037(17) [Angstrom], beta = 110.081(2)o, V = 2201.3(6) [Angstrom]3 and Z = 4.
PHOTOCHEMICAL SYNTHESIS OF DNA GROOVE-BINDING PYRROLO-[1,4]-BENZODIAZEPINES
Bentley Curry*, Tiffany R. Hammond, David T. Cutter, and Wolfgang H. Kramer, Millsaps College, Jackson, MS 39210
Pyrrolo-[1,4]-benzodiazepines have been shown to be efficient DNA groove-binding reagents. The correct twist is important to maintain the groove-binding properties. The decarboxylative photocyclization is offering an efficient way to synthesize a variety of pyrrolo-[1,4]-benzodiazepine derivatives. The stereochemistry is controlled by a memory of chirality effect via the 1,7-triplet biradical intermediate during the photochemical key step. Variation of chromophor and linker allow access to new structures with different DNA-binding properties.
Meeting Room 2
8:30 SEPARATION OF METALLIC NITRIDE FULLERENE (MNF) NANOMATERIAL MIXTURES VIA SELECTIVE ORGANIC FUNCTIONALIZATION
Helen Yu (1*), Katie Carpenter (2), Janice Paige Phillips (1), and Steven Stevenson (1*), (1) University of Southern Mississippi and (2) Mississippi University for Women, Columbus, MS 39701
The recent discovery of metallic nitride fullerenes (MNFs) has led to an exploration of their fundamental properties and application areas. Enthusiasm is due, in part, to the unique structural arrangement of atoms. Namely, the inorganic metallic nitride nanocluster is trapped inside a carbon fullerene cage to form the MNF structure. The charge transfer of the cluster to the cage combined with the presence of transition and 4f block metals creates a new type of molecular structure for study. However, the availability of purified MNF samples for research is hampered. The expense and low throughput from HPLC and the difficulty in their isolation are due to a complex soot extract mixture containing empty-cage fullerenes (e.g. C60, C70, C76, C78, C82, C84, etc), classical metallofullerenes (e.g. no nitrogen encapsulated, Sc@C82, Sc2@C84, Gd@C84, etc), and MNFs (e.g. Sc3N@C80, Gd3N@C80, etc). In this research presentation, we describe an alternative approach to overcome these separation hurdles by taking advantage of differences in cage surface reactivity. Namely, we have discovered and developed selective reagents which preferentially bind to contaminant fullerenes but to a lesser degree the desired MNF nanomaterials. Results indicate the removal of significant quantities of contaminant fullerenes with isolable amounts of unreacted MNFs.
8:45 TOWARDS THE SYNTHESIS OF A PERYLENEDIIMIDE WITH TRIPLE TAILS ATTACHED TO IMPROVE ITS SOLUBILITY
Amarachukwu Imediegwu (1*), Ramarkrishna Samudrala (2), and Daniell L. Mattern (2), (1) Mississippi University for Women, Columbus, MS 39701 and (2) University of Mississippi, University, MS 38677
Donor-sigma-acceptor-lipid molecules can be used as part of a miniature electrical circuit. If the donor and acceptor are chosen correctly, the circuit can rectify current (pass electricity in only one direction). A common acceptor molecule used is perylendiimide, which can be attached to the donor molecule through one of its imide nitrogens. However, perylenediimide is known to be very insoluble and so a lipid tail is attached to the other imide nitrogen to make the molecule soluble. The lipid tail also aligns the molecules in a monolayer for electrical testing. Double "swallowtails" work particularly well. So we attempted to synthesize a triple swallowtail to see if it would work better. We began by displacement of a tetrabromide with three alkoxide groups. The plan was to then displace the fourth bromide with azide and then follow-up with the reduction of the azide to create a primary amine with triple swallowtails. The first reaction appears to have proceeded only part way. More vigorous conditions may be needed to replace three bromines.
9:00 SPHERICALLY-PROPAGATING THERMAL POLYMERIZATION FRONTS IN A SEQUENTIAL INTERPENETRATING POLYMER NETWORK
John A. Pojman (1*), Burcu Binici (1), Dionne I. Fortenberry (2), Kayce C. Leard (1), Marcus Molden (1), Nesrin Olten (3), and Sam Popwell (1), (1) University of Southern Mississippi, Hattiesburg, MS 39406; (2) Mississippi University for Women, Columbus, MS 39701, and (3) Kocaeli Universitesi, Izmit Turkey
We demonstrate for the first time spherically-propagating frontal polymerization that also exhibits spin modes. We developed an interesting system in which we prepare a sequential IPN using the amine-catalyzed Michael addition of a trithiol to a triacrylate to create a rubbery gel. The gel suppresses convection and bubble formation during front propagation. A peroxide is also present to act as a thermal initiator. The front propagates via free-radical polymerization of the remaining triacrylate after being initiated photochemically in the center of the reactor. It is possible to prepare the rubbery gel in any shape and then initiate thermal frontal polymerization. So called 'spin modes' were observed for the first time in spherically-propagating fronts in which waves of polymerization propagate on the expanding spherical front.
9:15 RELIABLE SYNTHESIS OF A VERSATILE GRUBBS-TYPE METATHESIS PRECURSOR
Erika Shaffer* and Hans J. Schanz, Loyola University New Orleans, LA 70118 and University of Southern Mississippi, Hattiesburg, MS 39406
Over the past four decades, metathesis has evolved to become a highly valuable and versatile tool in organic and polymer synthesis. Since the early 1990s ruthenium-based Grubbs-type metathesis catalysts, in particular Grubbs' first and second generation catalyst and Hoyveyda-Grubbs catalyst, have immensely broadened the application spectrum of this reaction due to their high tolerance towards functional groups as well as moisture and molecular oxygen compared to homogeneous molybdenum-based systems. In our research project, we targeted the reliable synthesis of a well-known ruthenium complex with a 3-phenylindenylidene carbene moiety which is precursor to a highly active class of Grubbs-type catalysts. The advantages of the corresponding catalyst class is not only economically much more feasible than commercially available Grubbs-catalyst but also displays unique thermal stability combined with equal or even surpassing catalytic activity. Moreover, the prepared catalyst precursor is much more robust than the according precursor to Grubbs' catalysts and therefore, has much more potential for catalyst modifications. Up to our research efforts, the shortcoming was the unreliable synthesis published in the literature which afforded a dimeric species more often than the desired complex. We have identified the dimeric species plus one intermediate of the formation for the precursor and developed a straightforward and reliable protocol its synthesis.
9:30 THE SYNTHESIS OF NEW AMINO-2-PYRIDINE CARBOXYLIC ACIDS AS LIGANDS FOR DESIGNING CRYSTALLINE HOST-GUEST MATERIALS
Ramadan Ali Bawa* and Alicia M. Beatty, Mississippi State University, Mississippi State, MS 39762
The design and synthesis of crystalline host-guest materials has recently been a topic of interest for a number of research groups. Hydrogen bonds are a significant tool in crystal engineering as they can be resilient enough to tolerate entering and departing guest molecules. Controlling the cavities of layered metal complexes is very important, since such materials can produce tunable electronic, magnetic, optical, catalytic and storage properties. Bidentate ligands such as 2,4- and 2,5-pyridine dicarboxylic acids have been studied and shown promising results with both Ni(II) and Co(II) salts. In order to combine metal-containing dicarboxylic acids with metal-containing amines, pyridine-based bidentate ligands containing amino groups will be synthesized. The resulting Ni(II) and Co(II) complexes and each of these bidentate ligands will be used to create pillared layered metal complexes. These new solids will be compared to previous complexes in terms of thermal stability, the strength of hydrogen bonding and flexibility toward accommodating the entering and departing of guest molecules.
9:45 TOWARD THE ORGANIC SYNTHESIS OF WATER-SOLUBLE PRECURSORS FOR METALLIC NITRIDE FULLERENE (MNF) PHARMACEUTICALS
Praveen Madasu*, Erin Fortenberry, Ryan Stephen, Janice Paige Phillips, and Steven Stevenson*, University of Southern Mississippi, Hattiesburg, MS 39406
Metallic Nitride Fullerenes (MNFs) of medical interest include the Gd3N@C80 structure, which contains an entrapped trimetallic gadolinium nitride nanocluster inside a carbon cage of 80 atoms. If it can be rendered water-soluble, the Gd3N@C80 MNF is of prime interest as an MRI contrast agent. However, as the MNF carbon cage surface is hydrophobic, it is necessary to develop a synthetic approach to impart water-solubility to the MNF cage via hydrophilic functionalization. In this presentation, we describe results for the synthesis of desired water-soluble precursor reagents. Upon preparation of these precursors, the hydrophilic functionality can be attached to the cage surface using cycloaddition chemistry.
10:00 POLYMERIZATION SYSTEMS USING MICROENCAPSULATED REACTION COMPONENTS
Sammy Popwell*, Brian McFarland, and John A. Pojman, University of Southern Mississippi, Hattiesburg, Mississippi 39406
Microencapsulation is a process by which a liquid or solid core material is surrounded by a continuous layer of polymeric material. Encapsulation offers the benefit of compartmentalizing individual reaction components, resulting in an increase in pot life for many systems as well as a controlled release to some degree. A significant increase in pot life of frontal polymerization systems has been achieved through the microencapsulation of thermal free-radical initiators via an interfacial polymerization process. Interfacial polymerization has also been used to successfully encapsulate Ruthenium based catalyst for use in metathesis polymerization. Current work focuses on encapsulating a tertiary amine via a novel encapsulation technique based on thiol addition chemistry. The amine would catalyze its own encapsulation by addition of a trithiol to a multifunctional acrylate to form a crosslinked polymer shell.
10:15 OXIDATION OF BENZO[A]PYRENE BY IMMOBILIZED LACCASE OF TRAMETES VERSICOLOR ON FUNCTIONALIZED KAOLINITE
Xiaoke Hu*, Xueheng Zhao, and Huey-Min Hwang, Jackson State University, Jackson, MS 39217
Benzo[a]pyrene (BaP) have toxic, mutagenic and/or carcinogenic properties and promote the great environmental concerns of contamination of soils and aquifers. Laccase of Trametes versicolor can oxidize aromatic compounds in the presence of mediator such as 2, 2![.sup.-]-azino-bis-3-ethylbenzothiazoline-6-sulfonic acid (ABTS). The laccase of Trametes versicolor was immobilized on the functionalized kaolinite particles in order to enhance the stability of the free enzyme. The functionalization of the kaolinite was demonstrated by using organosilane namely 3-aminopropyltriethoxysilane (APTES), which modified the surface properties of the kaolinite, enabling the kaolinite to be an effective support for immobilization of biological molecules. The results showed that the half life time ([t.sub.1/2]) of the immobilized laccase to oxidize substrate is 58.5 h. After 87 hours oxidation, the amount of BaP in the reaction system was decreased to 36% of the initial concentration of 20 IM. According to the HPLC analysis, the oxidation products including 1, 6-benzo[a]pyrene dione (1,6-BaQ), 3, 6-benzo[a]pyrene dione (3,6-BaQ) and 6, 12-benzo[a]pyrene dione (6,12-BaQ) were identified. The spread plate method was used to measure the cytotoxicity of the products mixture of BaP after oxidation by the immobilized laccase. The results indicated that the viability counts of heterotrophic bacteria assemblages of river water increased 18.3 times after the oxidation. Therefore, cytotoxicity of the products mixture was decreased significantly after treatment with the immobilized laccase. This research was supported by (1) the U. S. Department of the Army grant # W911NF-04-1-0327 and (2) the National Institutes of Health (SCORE S06 GM08047) to Jackson State University.
10:45 STABILITY OF CURCUMIN UNDER DOMESTIC COOKING CONDITIONS AND SYNTHESIS OF WATER-SOLUBLE CURCUMIN
Tamara Williams, Kristie Blair, and Jiben Roy*, Mississippi University for Women, Columbus, MS 39701
Curcumin is a bioactive compound found in the Curcuma longa plant (commonly known as turmeric spice) that is now considered to be a potential candidate for future drug for many diseases including cancer and Alzheimer's. As turmeric has been used as spice in many countries, it would be interesting to see the stability of curcumin under do mestic cooking conditions. On the other hand, curcumin is insoluble in water, so water-soluble curcumin and its stability will be a plus to pharmaceutical and cosmetic industry. Curcumin was found to be stable when cooked in vegetable oil or refluxed in water. The detail results on the stability of curcumin as well as the synthesis of water-soluble curcumin by glycosylation in presence of Lewis acids will be presented.
11:00 HPLC OF METALLIC NITRIDE FULLERENE (MNF) CYCLOADDITION REACTION MIXTURES
Katie Carpenter (1*), Ryan Stephen (2), Janice Paige Phillips (2), and Steven Stevenson (2*), (1) Mississippi University for Women, Columbus, MS 39701 and (2) University of Southern Mississippi, Hattiesburg, MS 39406
The Metallic Nitride Fullerene (MNF) nanomaterials consist of an encapsulated trimetallic nitride cluster trapped within a carbon cage housing. Metals which can be encapsulated include Group IIIB and lanthanide elements. The carbon cage (e.g. 80 carbon atoms) surface reactivity can be "tuned" by judicious selection of the internal metal atoms. Results indicate that Sc3N@C80 and Gd3N@C80 MNFs have different reactivities and kinetics in cycloaddition reactions. Their reaction product mixtures contain an array of species including unreacted MNFs, monoadducts and higher adducts. Of interest is the bonding sites of the adduct to the cage carbons. To address questions of regiochemistry, we must obtain purified samples from reaction mixtures for X-ray crystallography studies. Results indicate that HPLC can successfully separate unreacted MNFs and their adducts.
11:15 HOT SCIENCE: COLD MOLECULES
Michael S. Elioff, Mississippi University for Women, Columbus, MS 39701
Ion imaging, developed by David Chandler of Sandia National Laboratories and Paul Houston of Cornell University, is a technique for determining the velocity distribution of molecules or molecular fragments and then using that distribution to deduce the dynamic properties of the parent molecule. The technique has been applied to problems of chemical reaction dynamics, photofragment formation, inelastic scattering, and, more recently, cold molecule formation. In particular, the technique was used to measure the translational temperature of nitric oxide molecules translationally cooled via single collisions with argon atoms. We have produced significant numbers ([10.sup.8]-[10.sup.9] molecules [cm.sup.-3] per quantum state) of translationally cold NO([.sup.2][[PI].sub.1/2],j'=7.5) molecules in a specific quantum state with an upper-limit laboratory velocity of 15[+ or -]1 m/s, corresponding to an 406[+ or -]23 mK upper-limit of temperature, in a crossed molecular beam apparatus. The technique, which relies on a kinematic collapse of the velocity distributions of the molecular beams for the scattering events that produce cold molecules, is general and independent on the energy of the colliding partner.
11:30 WATER DISPERSED MATERIALS
Jola Marszalek* and John A. Pojman, University of Southern Mississippi, Hattiesburg, MS, 39406
The focus of this study is to prepare hydrophobic polymeric materials in which an aqueous phase is distributed throughout the polymer matrix as droplets. Depending on the composition of the aqueous phase, the resulting material could respond to various external stimuli, such as magnetic fields, electric fields, or volatile compounds. The thin films are prepared via reverse microemulsion polymerization of a surfactant, water, and monomer mixture. The surfactant, Aerosol-OT is employed to encapsulate the nanometer-sized aqueous molecules within a surfactant monolayer. In determining the area of two-phase reverse microemulsion a phase diagram is created.
11:45 N-CHIRAL NICKEL COMPLEXES: HIGH DIASTEREOMERIC RESOLUTION UPON COORDINATION OF DIHYDROSALEN LIGANDS WITH A CHIRAL BACKBONE
Ken Long* and Hans J. Schanz, University of Southern Mississippi, Hattiesburg, MS 39406
C2-symmetrical 1,2-trans-diamines display remarkable versatility as chiral backbones with respect to their use in Asymmetric Synthesis. One of the most widely used ligand classes are C2-symmetric salens, double Schiff base derivatives from chiral, vicinal diamines and two salicylaldehyde units. These tetradentate ligands are successfully used in manganese and chromium mediated asymmetric epoxidation reactions as well as the asymmetric, Co-mediated hydrolysis of racemic epoxides. In an effort to develop more powerful ligand designs, we synthesized an array of C1-symmetric dihydrosalen ligands. In their corresponding Ni(II) complexes, the metal center is coordinated by an sp3-nitrogen atom, and subsequently, inversion at this nitrogen atom is terminated. As a result, a new chiral center is formed, and in respect to the given chirality in the backbone, the two possible N-configurations result in two possible diastereomers. In our investigations, we have found a high degree of diastereomeric resolution for almost all complexes. The presentation will convey ligand and metal complex syntheses.
12:00 APPLYING SNELL'S LAW TO FRONTAL POLYMERIZATION
Shanna Lavergne (1*), Burcu Binici (1), Nesrin Olten (2), and John A. Pojman (1), (1) University of Southern Mississippi, Hattiesburg, MS 39406 and (2) Kocaeli Universitesi, Izmit Turkey
Snell's Law gives the relationship between the angles of incidence and refraction for a wave passing through two media with different refractive indices. Different indices means different front velocities. We studied thermal fronts of triacrylate polymerization containing a clay filler. Two domains were created in which the concentration of peroxide initiator was different. The angle of the front at the interface was measured. Reasonable agreement with predictions of Snell's Law were found.
12:15 WATER-SOLUBLEN-HETEROCYCLIC CARBENE (NHC) LIGANDS: ACCESS TO WATER-SOLUBLE LATE TRANSITION METAL COMPLEXES
Matthew Anderson* and Hans J. Schanz, University of Southern Mississippi, Hattiesburg, MS 39406
Transition metal mediated catalysis based on complexes bearing water-soluble phosphines has become a widely investigated field. In contrast, research on the chemistry of NHC ligands, also called phosphine mimics, which provide solubility in aqueous media is still in its infancy. The complete or partial substitution of phosphine versus NHC ligands has expanded the application spectrum of several catalytic processes, namely Rumediated olefin metathesis and Pd and Ni-mediated C-C and C-N bond formation reactions. In our investigations, we have synthesized various water-soluble NHC ligand precursors by reacting N-substituted imidazoles with propane sultone or 3-bromopropanoic acid in a straightforward procedure. The resulting imidazolium salts readily form the respective bis-NHC silver(I) complexes upon reaction with Ag2CO3. We currently also investigate the use of these ligands for Grubbs-type Rubased olefin metathesis catalysts. The presentation will convey the ligand and complex syntheses.
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|Publication:||Journal of the Mississippi Academy of Sciences|
|Date:||Jan 1, 2006|
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