A comparison of the reduction of benzoquinone in solvents of two different polarities. JUAN ALICEA (Dowling College Oakdale, NY 11769) JOHN MILLER (Brookhaven National Laboratory, Upton, NY, 11973)

Benzoquinone derivates are biologically active compounds that are important in photosynthesis as electron carriers. The first and second reduction potentials of benzoquinone are -0.4V and -1.24V, respectively. These potentials, however, have been determined electrochemically in polar solvents with high concentrations of electrolyte. Previously, it was reported from electrochemistry that solvent polarity has little effect on the reduction potential. We believe that our data question that report. Low polarity calculations have been made, but there is little experimental data. We have titrated a fixed amount of benzoquinone with cobaltocene as a reducing agent in tetrahydrofuran (THF) and acetonitrile, separately. THF and acetonitrile have dielectric constants of 7.6 and 38, respectively. Cobaltocene was added to a solution of benzoquinone in increments of one tenth of one equivalent of cobaltocene to benzoquinone up to one equivalent. Thereafter, cobaltocene was added in increments of one fifth of one equivalent up to four equivalents. Continuous wave spectra were obtained after each addition from 200 - 800 nm. The experiments were carried out in an inert atmosphere. The data was analyzed using the data analysis program Igor with functions that we created. The fit for the THF spectra at 454 nm yielded an equilibrium constant of 1.316 and molar extinction coefficient of 5039. The free energy change at 298K was calculated to be -7.05V. The reduction in acetonitrile produced a much different result. The concentration of benzoquinone anion increased with each addition of cobaltocene up to 1.3 equivalents linearly. Thereafter, the concentration of benzoquinone anion decreased. We believe that cobaltocene reduces the benzoquinone anion to the dianion. Thus we conclude that, if the reduction potential change due to solvent polarity is distributed equally to cobaltocenium and benzoquinone, each has a change of -0.4V. In an attempt to characterize the equilibrium between the benzoquinone anion and dianion we will attempt the reaction in a solvent of intermediate polarity. We will also attempt to react less easily reduced quinones.

Caffeinated ionic liquids. KIJIANA KERR (Queensborough Community College Bayside, NY 11364) JAMES WISHART (Brookhaven National Laboratory, Upton, NY, 11973)

Ionic liquids are defined as materials containing only ionic species without any neutral molecules and exhibiting a low melting point (usually below 100oC). Recently there has been an increased interest in preparing ionic liquids from biorenewable precursors. We have been investigating the potential of using caffeine as a precursor for ionic liquids. Preliminary attempts to quaternize caffeine by attaching a hydroxyl, ether and benzyl substituents to the C-3 position of the imidazole ring have been unsuccessful or required long reaction time. We are currently repeating these reactions using microwave assisted synthetic techniques and other alkylating reagents. Microwave assisted synthetic reaction conditions such as temperature, the nature of the reaction solvent and length of reaction have been continuously varied, however the results have also proven inconclusive. Once successful the quaternized salts will be converted to ionic liquids bearing various anions and the physical properties will be investigated. The results of the microwave assisted synthesis and the physical properties of the ionic liquids will be reported.

Conditioned Place Preference to Inhaled Acetone and the Effects on Locomotor Behavior and 18FDG Uptake. JENNIFER PAI (Cornell University Ithaca, NY 14853) STEPHEN DEWEY (Brookhaven National Laboratory, Upton, NY, 11973)

Acetone is a component in many inhalants that have been widely abused. While other solvents have addictive potential, such as toluene, it is unclear whether acetone alone contains addictive properties. The locomotor, relative glucose metabolism and abusive effects of acetone inhalation were studied in animals using the conditioned place preference (CPP) paradigm and [¹⁸F]2-fluorodeoxy-D-glucose (¹⁸FDG) imaging. The CPP apparatus contains two distinct conditioning chambers and a middle adaptation chamber, each lined with photocells to monitor locomotor activity. Adolescent Sprague-Dawley rats (n=16; 90-110 g) were paired with acetone in least preferred conditioning chamber, determined on the pretest day. The animals were exposed to a 10,000 ppm dose for an hour, alternating days with air. A CPP test was conducted after the 3rd, 6th and 12th pairing. In these same animals, the relative glucose metabolism effects were determined using positron emission tomography (PET) imaging with ¹⁸FDG. Following the 3rd pairing, there was a significant aversion to the acetone paired chamber (190.9 ± 13.7 sec and 241.7 ± 16.9 sec, acetone and air, respectively). After the 6th pairing, there was no significant preference observed with equal time spent in each chamber (222 ± 21 sec and 207 ± 20 sec, acetone and air-paired, respectively). A similar trend was observed after the 12th pairing (213 ± 21 sec and 221 ± 22 sec, acetone and air-paired, respectively). Locomotor analysis indicated a significant decrease (p < 0.05) from air pairings to acetone pairings on the first and sixth pairings. The observed locomotor activity was characteristic of central nervous system (CNS) depressants, without showing clear abusive effects in this CPP model. In these studies, acetone vapors were not as reinforcing as other solvents, shown by overall lack of preference for the acetone paired side of the chamber. PET imaging indicated a regionally specific distribution of ¹⁸FDG uptake following acetone exposure. Further studies using different concentrations are required to better understand the locomotor and behavioral effects of acetone. This study confirms that the combination of microPET and the CPP paradigm can be used to elucidate the effects of abused solvents vs. non-abused solvents in inhalants.

Experiment Design and Setup for Laser-Induced Fluorescence Spectroscopy of Metal-Containing Free Radicals. LAURA FREDRIKSEN (University at Albany Albany, NY 11934) TREVOR SEARS (Brookhaven National Laboratory, Upton, NY, 11973)

Small, metal-containing free radicals are models for the active site in heterogeneous catalysts, such as those used industrially for hydrodesulfurization of petroleum and in automobile exhaust gas treatment to remove oxides of nitrogen. Most catalysts employed in these processes today employ expensive, rare, or precious metals, and one of the goals of the research is to investigate the properties of potential cheaper replacements made from compounds of common, less expensive transition metals. A new experimental apparatus is being built to study the electronic structure of these metal-containing radicals in the gas phase. The new experiment will use laser ablation combined with a supersonic expansion of inert gas or inert gas seeded with a small percentage of reactive molecules to form beams of small metal clusters or cluster compounds. The beams will be studied spectroscopically using an optical parametric oscillator based laser system that provides narrow-band tunable light at wavelengths ranging from the infrared to the ultraviolet. The primary spectroscopic technique to be used is laser-induced fluorescence. We are particularly interested in the lowest energy excited states of the radicals, since their energies and properties can be used to infer likely chemical properties. As a first test for the machine, we will attempt to record the spectrum of vanadium nitride (VN), which has a strong visible spectrum that is well understood from previous studies. However, VN is also predicted to have several low-lying electronic states for which little experimental information is presently available. This experiment is within the first stages of being organized and built; considerable attention has been focused on building structures vital to the experiment, such as a table designed to support the vacuum system, laser shrouds, etc. This experiment should be expected to carry on for years, covering the spectra of a number of different metal-containing molecules.

Microwave Synthesis and Characterization of Pyridine-based Ionic Liquids including Vitamin(B3). ANNU IPE (Queensborough Community College Bayside, NY 11364) DR.JAMES WISHART (Brookhaven National Laboratory, Upton, NY, 11973)

Ionic liquids are salts that are liquid at or below room temperature. Ionic liquids have no measurable vapor pressure and are considered environmentally friendlier than the volatile organic solvents currently being used such as benzene, toluene and methylene chloride. We are exploring the synthesis of ionic liquids from pyridine-based precursors including bio-renewable compounds, such as nicotinic acid (Vitamin B3) using a microwave reactor. Performing the synthesis using microwave energy saves both time and energy. Synthesis performed by conventional methods may take days, whereas in a microwave reactor synthesis is achieved in less than thirty minutes. The potential ionic liquids are synthesized by reacting nicotinic acid with a variety of alkyl and aryl halides to prepare the corresponding quaternized halide salts. The halide salts are then converted into a series of ionic liquids with varying anions including phosphate, bis(trifluoromethylsulfonyl)imide (NTf2) and dicyanamide. Physical properties including melting point, viscosity, conductivity and water content will be investigated. Preliminary results indicate that we have successfully prepared pyridinium ionic liquids containing hydroxyl and ether substituents with phosphate and NTf2 anions. Nicotinic acid (an analog of pyridine) was more difficult to alkylate and reaction with most alkyl halides was unsuccessful. However allyl bromide was found to be a successful alkylating agent for quaternizing nicotinic acid. Future research will focus on relating the structure of these new compounds to their properties.

Physical properties of racemic ionic liquids containing a 2,3-dihydroxyl-propyl unit. JASMINE HATCHER (Queensborough Community College bayside, NY 11364) JAMES WISHART (Brookhaven National Laboratory, Upton, NY, 11973)

Ionic liquids have generated much interest due to their potential green chemistry applications. Green chemistry focuses on the design of chemical processes that reduce or eliminate the use and production of environmentally hazardous substances. Ionic liquids are environmentally friendlier solvent alternatives to traditional volatile (and hazardous) organic solvents because of their lack of vapor pressure. This means that they do not evaporate and therefore are considered safer. Ionic liquids are organic salts that have a melting point that is less than 100oC. They usually have a large cation and a relatively small anion. We report here on the synthesis and preliminary characterization of chiral ionic liquids. Chirality describes a molecule that is non-super imposable on its mirror image. This makes the molecule more asymmetrical and discourages solidification because it frustrates packing. In order to make the molecule chiral, we took a chiral auxiliary, 3-chloro-1,2-propanediol, and added it to a tertiary amine. Some of the tertiary amines used were DABCO (diazobicyclo [2,2,2] octane) and 1-methyl imidazole. We then converted the chiral halide salt into potential ionic liquids by anion exchange. Anion exchange was accomplished by reacting the halide salt with an acid or a metal salt that has the desired anion. Anions studied include phosphate, dicyanamide and bis (trifyl)imide. A large problem with ionic liquids is that they are very viscous. This makes it difficult to work with them at room temperature. Preliminary results suggest that adding a chiral center reduces viscosity. Future work will focus on conductivity and viscosity measurements of these new species.

Relative Cerebral Glucose Metabolism and Behavioral Studies of Toluene Abuse using 18FDG in Toluene-exposed Rats. JOSEPH CARRION (City College of New York New York, NY 10031) DR. STEPHEN DEWEY, DR. WYNNE SCHIFFER (Brookhaven National Laboratory, Upton, NY, 11973)

The addictive dynamics of inhalants, along with the possible physiological and biochemical disruptions they may cause in the brain are not fully understood. Toluene, an abused solvent used as a base in many glues and household products, has been shown to produce a reinforcing response in a Conditioned Place Preference (CPP) paradigm. The expression of positive reinforcement behavior that is connected with a perceived reward may be reflected with changes in cerebral glucose metabolism, the brain's main metabolic source of energy. In this study we used a three chambered (black/gray/white) conditioning apparatus in an unbiased-design. Before any exposure, a pretest was conducted and the time spent in each chamber was measured by automated photocells; with animals spending equal time in each chamber (black: 258.7 ± 28; white: 269 ± 28 sec). A conditioned response to 2000 ppm of toluene vapors was obtained after 7 and 13 pairings from male Sprague-Dawley rats (n=8). On the 13th pairing test, n=3 animals showed a significant (p = 0.001) preference for the drug-paired side. Conditioned Place Aversion (CPA) was expressed by n=4 animals (p > 0.06). The locomotor activity measured were significantly lower (p < 0.05) for toluene-paired days as compared to the air-paired days. We have conducted an analysis of relative cerebral glucose metabolic rate using 2-deoxy-2-fluro-D-glucose (18FDG) and Micro Positron Emission Tomography (MicroPET). The results of these scans indicate significant increases in the striatum, thalamus, and parietal cortex for animals that expressed a preference, and decreases in these same areas for animals that showed an aversion. Further studies on toluene's lipid solubility may clarify the aforementioned changes, as well as give insight into whether these changes in the animal model are permanent or reversible.

Self-Assembly of Monolayers of Alkylthiol Chains and Oligomers In Silico Using Molecular Dynamics Simulations. JULIE STERN (State University of New York - Stony Brook Stony Brook, NY 11794) MARSHALL D. NEWTON (Brookhaven National Laboratory, Upton, NY, 11973)

Self-assembled monolayers (SAMs) consist of alkane chains on substrate and are used to form simple models of the natural phenomena of self-organization and its physical and chemical properties. The alkane chains can be simple hydrocarbons or more complicated saturated chains with additional structure and side groups. In this study, alkythiol chains, hydrocarbon chains on sulfur, and OPE (oligophenyleneethynylene), phenylene-ethynylene oligomers, on sulfur at both ends of the chains, were studied for their self-assembly patterns and properties. These monolayer structures were designed and built in-silico using standard computational software and algorithms including AMBER force fields and Gaussian for the calculation of atomic charges. The "in-silico molecular synthesis protocol" was specifically designed and developed for this study. Molecular dynamics (MD) simulations were used to study structural changes in the SAMs at the atomic level. Starting from the initial molecular packaging of the monolayers and simulating with MD, lower energy stable structures emerged from the alkylthiol and dithiol-OPE monolayers corresponding to the self-assembly pattern. The alkylthiol monolayer produced a pattern of self-assembled tilt. The dithiol-OPE monolayer resulted in a distinctive and ordered herringbone pattern.

Synthesis of aryl and alkyl substituted ionic liquids. HEIDI MARTINEZ (Queensborough Community College Bayside, NY 11364) JAMES WISHART (Brookhaven National Laboratory, Upton, NY, 11973)

Ionic Liquids continue to attract widespread attention because of their potential as environmentally friendlier solvent alternatives. We have previously reported on the synthesis of a series of symmetrical quaternary ammonium ionic liquids. These ionic liquids were of unique structural types bearing phosphate and bis(trifyl)imide anions. However, the symmetrical nature of the cations resulted in ionic liquids with high viscosity, an undesirable property for most applications. We report here on the synthesis of less symmetrical analogs of the compounds previously prepared with the goal of producing less viscous ionic liquids. Particular focus is on the synthesis of quaternary ammonium cations bearing aryl and alkyl substituents. Investigation of the effect on the physical properties of ionic liquids resulting from this structural variation of the cation involved is also being investigated. Benzyl chloride was the main reagent used for the synthesis of aryl salts whereas short chain alkyl halides were used to synthesize the alkyl substituted ammonium salts. The reactions were done under low temperature reflux conditions with stirring. The resultant compounds were purified using various methods including modified charcoal and alumina columns. The halide salts of varying structural types were converted into ionic liquids using four different anions. This was achieved mainly by metathesis reactions using the metal salt or acid of the desired anion. Structure confirmation of the product was performed using C-13 and H-1 NMR. Liquids are screened for residual halide and water content and then characterized. Physical properties including conductivity, viscosity, melting point, density and solvent properties will be studied.

The Effect of Ether and Hydroxyl Moieties on the Properties of Structurally Diverse Ionic Liquids. VANESSA HERNANDEZ (Queensborough Community College queens, NY 11364) DR. JAMES WISHART (Brookhaven National Laboratory, Upton, NY, 11973)

The attractive properties of ionic liquids, including negligible vapor pressure, high conductivity, low flammability, low melting points and recyclable nature, makes them ideal as environmentally friendlier solvent alternatives. They are currently being extensively investigated as alternative reaction media. We have prepared several series of ionic liquids containing cations based on pyrrolidine, imidazole, pyridine, and dabco species bearing ether and hydroxyl substituents. We report here on the synthesis and physical characterization of these types of compounds and the effect of the ether and hydroxyl functionalities. Previous reports have indicated that these substituents have an effect on viscosity. The characterization of these compounds is important because ultimately we want to be able to "custom design" ionic liquids to exhibit desired physical properties such as viscosity, conductivity and melting point. Variation in physical properties can be achieved by interchanging various cations and anions. Cations investigated include quaternary ammonium salts with hydroxyl or ether substituents. Anions investigated include phosphate, bis(trifluoromethanesulfonyl)imide, dicyanamide, bis(oxalato)borate and halides. The cations were first synthesized by reaction of an amine with an alkyl halide to produce a quaternary ammonium halide salt. The halide salt was then converted to a phosphate, bis(trifyl)imide, dicyanamide and bis(oxalato)borate to give potential ionic liquids. The conversion was achieved using metathesis reactions of the halide salt with the metal salt or acid of the desired anion. Structural confirmation was done using C-13, H-1 and P-31 NMR. Samples are analyzed for residual halide and water content and then characterized for their physical properties. Preliminary results indicate conductivity values of bis(trifluoromethanesulfonyl)imide species at 20 C in the range of 0.20 mS/cm and viscosity in the range of 500-550 cP. Continuing studies will focus on synthesizing and characterizing similar compounds with different anions and comparing their physical properties.

The Effect of Ionic Liquids on Conformationally-Controlled Intramolecular Electron Transfer in a Peptide-Bridged Donor-Acceptor System. HEATHER LEE (Rutgers University Piscataway, NJ 08854) JAMES WISHART (Brookhaven National Laboratory, Upton, NY, 11973)

In recent years, room-temperature ionic liquids (IL) have become popular media for a variety of chemical processes, including the storage of solar energy by photoinduced electron transfer, due to their intrinsic properties such as negligible volatility, high thermal stability, and high conductivity. Peptide bridged electron donor-acceptor systems have been important tools for studying electron transfer, and previous work has shown that various solvents influence the conformation of the peptide bridge and thereby control electron transfer rates. The cis/trans isomerization of proline peptides is a case in point. We report here on the influence of IL on rates of electron transfer across the diproline bridge in tetramethylrhodamine-pro₂-dimethyphenylenediamine (TMRA-Pro₂-DMPD). A distribution of intramolecular electron transfer rates is expected due to different proline cis/trans conformational distributions depending on the polarity of the IL. The experiment will be investigated in four different IL: N-methyl-N-hydroxypropylpyrrolidinium dicyanamide, N-methyl-N-hydroxypropylpyrrolidinium bis(trifluoromethanesulfonyl)imide, N-methyl-N-butylpyrrolidinium dicyanamide, and N-methyl-N-butylpyrrolidinium bis(trifluoromethanesulfonyl)imide. Methods of IL preparation were developed using microwave-assisted organic synthesis, and the IL were characterized for their physical properties. Combinations of different cations (containing alkyl or hydroxy alkyl substituents) and anions (hydrophobic or hydrophilic) resulted in IL with varying polarities. Using Reichardt's dye, a standard solvatochromic probe, the normalized solvent polarity indices E_T^N span a large range: 0.84, 0.70, 0.56 and 0.55 for P_1prOHNTf₂, P_1prOHDCA, P₁₄DCA, and P₁₄NTf₂ respectively. TMRA-Pro₂-DMPD is expected to have distributions of cis/trans configurations that depend on the polarity and hydrogen bond-donating ability of the IL. Time-correlated single-photon counting has been used to measure emission lifetimes (and electron transfer rates) of TMRA-Pro₂-DMPD in each of the four IL. Electron transfer rates will be calculated when the corresponding controls are completed. Inferences will be made concerning the influence of the IL on peptide conformation and electron transfer energetic.

The Relationship of Soil and Water Chemistry to the Preservation of Salamander Habitats in the Long Island Pine Barrens. CASSANDRA GILL (North Carolina Agricultural and Technical State University Greensboro, NC 27411) SONYA LAMB (North Carolina Agricultural and Technical State University Greensboro, NC 27411) TIM GREEN (Brookhaven National Laboratory, Upton, NY, 11973)

Although salamanders are the dominant vertebrate population in the ponds of the eastern United States, little is known about their habits. As a result, the extent of their decline worldwide is unknown. Growing urban development is converting woodlands and wetlands, reducing aquatic and terrestrial salamander habitat. Consequentially, most salamanders are threatened by habitat loss and water pollution. Forty percent of North American salamander species are considered to be at risk and the Eastern Tiger Salamander has been listed as endangered since 1983. Long Island Pine Barrens is the northern limit of the tiger salamander in its known range and a stronghold for this species. The purpose of this study is to develop an understanding of the chemical and biological factors that affect salamander population and distribution, identify possible threats to viability, and contribute to the development of a management plan to protect this species. Field studies and analysis activities include soil and water measurements important to the ecological functioning of coastal ponds in the Long Island Pine Barrens-Peconic River Complex. Water and soil samples were collected and analyzed in four natural ponds and were analyzed using colorimetric and spectroscopic methods. Multiple soil samples prepared in accordance and water samples were further analyzed for metals using inductively coupled plasma -atomic emission spectrometer (ICP). Tiger salamanders appeared to thrive in areas with low concentrations of pollutants and moderate levels of natural factors such as dissolved oxygen. The presence of tannin-lignin and the amount of suspended solids had an affect on the salamander populations showing that salamanders prefer an oxygen-rich environment that contains a low amount of decaying matter. According to our research, steady water depths are desired by the species as well. This work was completed as a small portion of the implemented Wildlife Management Plan being conducted by the Environmental and Waste Management Services Division at Brookhaven National Laboratory. The soil and water chemistry of ponds with and without tiger salamanders was analyzed in order to further investigate the decline of the species as well as aid in the conservation of salamander habitats.

Urban Dispersion Program. DOMINGO TEMPLONUEVO (Suffolk Community College Selden, NY 11784) JOHN HEISER (Brookhaven National Laboratory, Upton, NY, 11973)

The Urban Dispersion Program was developed to research how a chemical or airborne bacteria and virus that are release in air, will disperse in a city such as New York. The research will greatly help aid evacuation of people within the city and help save lives in case of a terrorist attack. There many mathematical models that already relate the fluid dynamics of chemical dispersion in air given a certain wind direction and speed. However, these models are slightly inaccurate in the city due to many factors that are involve such as car traffic, exhaust vents and building orientation which changes the wind direction in many different areas and elevation. Thus the Urban Dispersion Program or UDP had to simulate a chemical release using a safe known chemical tracer so that existing mathematical models can be compared and calibrated. UDP uses perflorocarbon tracers or PFTs to simulate a hazardous chemical release. PFTs gases is release in the air at a rate of 500 ml/min in different days and time while a device called Brookhaven Atmospheric Tracer Sampler or BATS collects air sample in a given time and time intervals. The BATS contain 23 sampler connected to an air pump that blows ambient air through each of the sampler in consecutive order. These samplers have a chemical compound called Ambesorb that adsorbs PFTs present in the air. Several BATS are scattered around the area of PFTs release point and are ran minutes after the release. There are other samplers that are use a handheld personal air sampler (PAS) that takes only one sample at a time using a Capillary Adsorbent Tracer Sampler or CATS, which also contains Ambesorb. After one run, the BATS and CATS are sent down to Brookhaven National Laboratory for analysis. The samples are then heated up and nitrogen gas is blown through it to desorb the PFTs in the Ambesorb. The PFTs that comes out goes through a gas chromatography and concentrations of each PFT are then calculated. Knowing the concentration and time and place where it was taken for each samples, a general picture of how the tracer spread through out the city is generated using a computer program. The result of the previous UDP research showed the variation of dispersion in different time of day even if the general atmospheric condition was the same. This variance is then accounted for to calibrate existing atmospheric models that can be use in an event of a chemical attack in the city.