CHEM 426/626 Reactive Intermediates According to Concordia’s Centre for Teaching and Learning Services: F un C ommunity I nteresting L esson plan R ules A xpectations S yllabus S upport T est (pre-) S mile Typical class grade distribution in the past Grades Winter 03 (26-6/20) Mark range UG Grad 0-49 F F 7 6 50 - 52 D- F 6 53 - 56 D F 5 4 4 57 - 59 D+ F 4 60 - 62 C- F 3 2 22 2 63 - 66 C C 2 11 1 1 67 - 69 C+ C 1 0 0 70 - 72 B- B- 0 A+ A A- B+ B B- C+ C C- D+ D D- F 73 - 76 B B 77 - 79 B+ B+ 80 - 85 A- A- 86 - 92 A A 1 grad regular great 1 grad 93 - 100 A+ A+ 3 undergrads practice presentation 1 undergrad and reading Who needs to know about reactive intermediates? 1. The chemist 2. The biochemist Singlet O2 Feat Nitric Oxide Battles Tuberculosis Simple, nonchiral molecule resolves racemates Experimental drugs release NO, which kills with surprising selectivity dormant as well as active tuberculosis cells Maureen Rouhi Sophie L. Rovner J. Am. Chem. Soc. 2004, 126, 10498. The paper Science 2008, 322, 1392. Release of the highly "reveals truly remarkable effects" of experimental reactive NO is "akin to a bomb blast that kills the parameters on the stereoselectivity, comments bacteria from within," says Clifton E. Barry III of Miguel A. Garcia-Garibay, a chemistry professor at the National Institute of Allergy & Infectious the University of California, Los Angeles. Diseases, in Bethesda, Md. C&E News December 1, 2008 C&E News August 23, 2004 2. The biochemist continued Pseudomonas putida P450 (P450cam) P450 from the soil bacterium P. putida is best characterized. The bacterium degrades camphor O P450cam O - + to obtain a carbon source for energy. First step: 2e , O2, 2H OH Something odd here?! Mechanism of alkane hydroxylation substrate-bound form Sono et al., Chem. Rev. 2850, 96 (1996) Nobel prizes The ultimate prize for recognizing what is “important”. 1967 (Manfred Eigen), Ronald Norrish, George Porter for their studies of extremely fast chemical reactions, effected by disturbing the equlibrium by means of very short pulses of energy (flash photolysis) 1971 Gerhard Herzberg for his contributions to the knowledge of electronic structure and geometry of molecules, particularly free radicals http://nobelprize.org/chemistry/laureates/ Nobel prizes 1994 George Olah for his contribution to carbocation chemistry 1999 Ahmed Zewail for his studies of the transition states of chemicalical reactionsreactions using femtosecond spectroscopy http://nobelprize.org/chemistry/laureates/ Reactive Intermediates CHEM 426/626 Some introduction Science has always strived to see smaller and smaller things and faster and faster events. Bengt Nordén, Presentation Speech, The Nobel Prize in Chemistry 1999 (Zewail) • Which reactive intermediates do you know? mechanisms! • How are they formed? breaking bonds • Here we are (mostly) interested in carbon species. carbon valencies • Which common molecules could be considered reactive intermediates?.