Research as a Driver of Educational Innovation: Some Reflections on the Outreach Program of an NSF Collaborative Research in Chemistry Project Dennis H. Evans Department of Chemistry, University of Arizona, Tucson, AZ 85721 (USA) Supported by NSF, CHE-0527003 …or, how I spent my summer vacation (seriously) J. Am. Chem. Soc. 1984, 106, 3039-3041. National Science Foundation Collaborative Research in Chemistry “Coupling Redox Processes to Drive Chemical Reactivity: New Catalysts for Hydrogen Production” Principal Investigators: Dennis H. Evans, Richard S. Glass and Dennis L. Lichtenberger, Department of Chemistry, University of Arizona The science: …To overcome these obstacles, this proposal derives inspiration from Nature. Hydrogenases are naturally occurring enzymes that couple low potential redox reactions to generate hydrogen. Iron-only hydrogenases utilize a cheap and abundant metal and operate in ambient conditions. The active site in the enzyme is a diiron center. The scientific challenge is to couple low potential redox reactions with reduction of a diiron center, an energetically unfavorable process. The proposed solution is to electronically couple a functional diiron system to a low potential redox ligand, and then drive the energetically unfavorable electron-transfer from the redox ligand to the diiron system by coupling it to an irreversible chemical reaction, that is, protonation and generation of H2… The outreach: …be mentored in the skills essential for multidisciplinary team approaches to problemsolving. A program to inspire underrepresented high school students to pursue careers in science, which takes advantage of Tucson’s large Hispanic and longstanding Native American populations (two minorities woefully underrepresented in science), is an integral part of this endeavor. SUMMER PROGRAM IN HYDROGEN RESEARCH FOR HIGH SCHOOL STUDENTS June 5-July 14, 2006 The CRC Hydrogenase Team Synthesis: Professor Richard Glass Dr. Jinzhu Chen Dr. Rudresha Kottani Ms. Uzma Zakai Mr. Matt Swenson Electrochemistry: Professor Dennis Evans Dr. Greg Felton PES/Computations: Professor Dennis Lichtenberger Ms. Tori Moser Mr. Taka Sakamoto Mr. Aaron Vannucci Mr. Ben Petro (Co-PI) (Postdoc) (Postdoc) (Graduate Student) (Graduate Student) (Co-PI) (Postdoc) (Co-PI) (Graduate Student) (Graduate Student) (Graduate Student) (Graduate Student) The NSF “Nugget”: Richard S. Glass, Dennis H. Evans, and Dennis L. Lichtenberger The University of Arizona Fe-Hydrogenase The Promise Hydrogen as our energy source benefits us because it is renewable, environmentally friendly and removes our dependence on foreign oil. The Challenge To make a hydrogen energy economy a reality major obstacles must be overcome that require new scientific knowledge. One such obstacle is the need for cheap, efficient, readily available catalysts for chemically combining two electrons (2e-) and two protons (2H+) from water to produce molecular hydrogen (H2) as well as catalysts for the burning of H2 in fuel cells to yield energy and water. Diiron active site computations synthesis electrochemistry The Idea To invent a catalyst we have been inspired by nature's catalyst, hydrogenase. As illustrated, Fe-hydrogenase is a complex protein which bears a catalytic core, the diiron active site, and electron transfer centers connecting the buried core to the electron donors at the protein surface. By directly attaching a versatile and easily made electron donor OC C N Fe Fe C O CN C O 2e2H+ directly to a simple chemical analogue of the diiron active site the need for protein and electron transfer centers vanishes. As shown, two electrons (2e-) enter the donor site, which then delivers them to the catalytic diiron site to combine with 2H+ to produce H2. This design requires new basic scientific knowledge because the internal 2e- transfer requires a conduit, a driving force to propel them energetically uphill, and the 2H+ must be delivered selectively at the diiron site to rapidly form H2. Spectroscopic and electrochemical data on the chemically synthesized catalyst candidates will afford the real-world measurements and the essential scientific understanding required for inventing a successful catalyst. S S S Cys H2 2H2 + O2 2H2O + Energy Hydrogenase Active Site X = OH¯ or H2O; Y = O or N http://metallo.scripps.edu/PROMISE/FEHASE.html Quinone Derivatives • Quinone/Hydroquinone derivatives of the disulfido compound are of special interest because of their potential redox properties. HO OH O O -2H+, -2eS S +2H+, +2e- OC Fe OC OC Fe CO S CO OC CO OC Fe OC S Fe CO CO CO Ms. Uzma Zakai Warmup: “Fp”-Dimer, [(5-C5H5)Fe(CO)2]2 (-C5H5)Fe(CO)2H + e(-C5H5)Fe(CO)2H- I/µA 300 2.07 mM Fp2 with increasing amounts of acetic acid. 250 200 150 100 50 [(-C5H5)Fe(CO)2]2 + 2e2(-C5H5)Fe(CO)2- 0 -50 -100 E(V): -1.25 -1.5 -1.75 -2 -2.25 -2.5 Felton, Glass, Lichtenberger and Evans, Inorg. Chem. 2006 (ASAP, 08/23/06, 10.1021/ic60984e) Cover Art for Inorganic Chemistry — are we ready for this? He 1 close comparison 11 10 9 8 Ionization Energy (eV) Ms. Tori Moser, 2006 SUMMER PROGRAM IN HYDROGEN RESEARCH FOR HIGH SCHOOL STUDENTS June 5-July 14, 2006 Recruit high school students and teachers for a six-week program of research in the CRC laboratories • • Concentrate on Tucson high schools (e.g., Sunnyside High School is >80% Hispanic) • Students and teachers will receive a stipend; 5 days/week, 8 hr/day • Form teams of two students and one teacher • The teams will work with the faculty, postdocs and graduate students in the CRC on projects of direct importance to CRC • At the end, each team will write a report and prepare a presentation Questions • • • • • • • • Will anyone apply? (25 students; 3 teachers) Qualifications? (Excellent) Will the students understand?(Mixed) Will teachers want to spend the summer with students? (No problem) Shall we start with a week of lectures on the hydrogen economy, relevant chemistry…? (Bored them to death) Shall we have exercises to introduce the students to laboratory techniques? (Essential) Will the laboratory projects be interesting? (They loved it) What will motivate them? (Feeling that they are helping the project) Thu Nguyen William Pickeral Sarena Debaca Sabino High School University High School Sunnyside High School Stefan Romero Jessica Peña Delissa Fimbres Sunnyside High School Desert View High School Palo Verde High School Wilma Amero Tim Barry Mark Calhoun Pueblo Magnet High School Salpointe Catholic High School Sabino High School The projects and presentations: • Amero, Nguyen, Peña: Optimization of chemical synthesis of quinones • Barry, Debaca, Romero: Development of an electrochemical method of preparing quinones • Calhoun, Fimbres, Pickeral: Computational study of a new hydrogenase mimic Adding Quinone To Backbone .20 grams of iron backbone, .19 grams of quinone, and 250 mL of THF. The UV light was on for a total of 7.5 minutes. Before UV light After UV light This is supposed to happen Starting at Neutral pH with 70 Coulombs to complete Reaction Color is Red At about 30 coulombs and an Acidic pH Instantaneous Color Change to Green This is not supposed to happen Team: Barry, Debaca, Romero Photo-electronic and Computational Analysis of Various Geometries of a Non-bridging Hydrogenase Model Delissa Fimbres Mark Calhoun William Pickeral 7/14/06 So what did we learn? • The students had very minimal prior laboratory experience, but they loved the lab • We shouldn’t start with a week of lectures • The teams are capable of developing their own ideas (electrosynthesis of quinones was suggested by Tim Barry) • Six graduate students and one postdoc were assigned to work with the participants. This was of crucial importance • Our expectations of prior knowledge of chemistry were unrealistically high THANK YOU VERY MUCH CRC (Collaborative Research in Chemistry) PROGRAM!