59th Annual Report on Research 2014

ACS PRF Narrative Report for Summer Student Research, 2014 Despite significant efforts, scientists are still trying to expand the ability to control the supramolecular assembly of anionic polyhedral and thereby tailor inorganic frameworks with desirable properties (i.e. catalysis, toxic waste remediation, gas storage, etc.). A preliminary survey of the Inorganic Crystal Structure Database (ICSD) and pertinent literature reveals that 1) anionic polyhedral and alkali cations tend to precipitate from solution in accordance with the valence-matching principle and 2) chemical hardness differences in mixed anion and mixed cation systems enable preferential cation-anion interactions and predictable structural connectivity. Undergraduate students’ research at Aurora University focused on the synthesis of mixed-anion inorganic frame works. There are about 10 undergraduate students who participated in the research program. The major instruments include Rigaku MiniFlex 600 powder X-ray diffractometer (PXRD) and Thermo Scientific Nicolet iS5 FT-IR Spectrometer. The undergraduate students started the research with study of the molybdenum (VI) species in aqueous solutions. The attempts were made to synthesize novel mixed-anion inorganic compounds composed of chloride-rich molecular [MoVIOmCln]6-2m-n anions and various alkali cations. The samples were prepared using sodium molybdate, alkali chloride (KCl and LiCl) in 3 M HCl and 6 M HCl solutions under different composition ratios, temperatures, and heating and cooling times. Table 1 lists some of the parameters. Table 1 Preparations of the Mixed-Anion Inorganic Compounds: Experiment: 1, Composition: 0.5 g Na2MoO4, 0.15g KCl, 25 ml 3M HCl. Temp. (°C): 50, 100. Heating Method: Hot plate. Experiment: 2, Composition: 0.5 g Na2MoO4, 0.05g KCl, 25 ml 3M HCl. Temp. (°C): 50, 100. Heating Method: Hot plate. Experiment: 3, Composition: 0.5 g Na2MoO4, 0.15g KCl, 25 ml 3M HCl. Temp. (°C): 150. Heating Method: Parr Oven. Experiment: 4, Composition: 0.5 g Na2MoO4, 0.05g KCl, 25 ml 3M HCl. Temp. (°C): 150. Heating Method: Parr Oven. Experiment: 5, Composition: 0.5 g Na2MoO4, 0.15g KCl, 0.50 g H3BO3, 25 ml 3M HCl. Temp. (°C): 50, 100. Heating Method: Hot Plate. Experiment: 6, Composition: 0.5 g Na2MoO4, 0.15g KCl, 0.50 g H3BO3, 25 ml 3M HCl. Temp. (°C): 150. Heating Method: Parr Oven. ** The trials of replacing of KCl with LiCl and replacing 6M HCl with 3M HCl were also conducted. The crystalline samples prepared were characterized by PXRD and FTIR. More than fifteen products were studied. In addition to this study, the complexes of yttrium isothiocyanate and crown ethers were also studied using the PXRD and FTIR. Due to the limited resources and time, the single crystal x-ray differction was not carried out. This research resulted in four posters at national and regional scientific meetings as listed below: Poster 1: Exploratory Synthesis and Characterization of Mixed-Anion Inorganic Frameworks, March 2014, Lewis University, Romeoville, IL Poster 2: Exploratory Synthesis and Characterization of Molybdate Compounds, April 2014, Governors State University, University Park, IL Poster 3: Exploratory Synthesis and Characterization of Molybdate Compounds, April 2014, Aurora University, Aurora, IL Poster 4: Application of Powder X-Ray Diffraction, August 2014, 248th ACS meeting, San Francisco, CA Students participated in the research with great enthusiasm and curiosity. They actively participated in each stage of the research. Through this study, the students gained the training in reading the literature, group discussion, experimental design, inorganic synthesis methods, characterization, data analysis, as well as presentation skills. They gained the understanding of effects of some factors such as pH, temperature, composition rations on chemical reactions. The students also gained fundamental principles of X-ray diffractions and the uses of powder X-ray diffractometer (PXRD), FTIR, and other equipments. They learned theory and applied it in practice. This not only promoted the students’ interests in chemistry research, but also gave them an opportunity to have experience in scientific applications. The future work will focus on the growth of the crystals, determination of the structures of the compounds, and the study of the relationship of the properties and the structures for the products.