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Ag. O N. [H(OEt 2 ) 2 ] +. [C(Ph) 3 ] +. -. -. C. C. C. B. B. B. H. H. H. 1. 1. 1. 1. 1. 1. 1. 1. 1. 2. 2. 2. (CH. ). +. Ru. Ru. CH-OH + (CH 3 ) 2 C=O. Ru. 3. 2. OTf. N O. N. OTf. O. R. u.
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Ag O N [H(OEt2)2]+ [C(Ph)3]+ - - C C C B B B H H H 1 1 1 1 1 1 1 1 1 2 2 2 (CH ) + Ru Ru CH-OH + (CH3)2C=O Ru 3 2 OTf N O N OTf O R u Parent carborane R R R u u u M e M M M e e e N O N N N O O O 1-Et carborane C l M M e e 1-Me carborane catalyst: + Ru - BAr THF f N CH O 3 BAr = B((3,5-(CF ) C H ) f 3 2 6 2 4 Hexabromo carborane 1-Bu carborane CsCB11H12 /ether + HCl(gas) - H [H(Et2O)2]+ CB11H12 - - H Carborane anion 1H NMR, CD3CN Known reactivity: Cations and anions olefin polymerization catalysis observed Carborane Acid H+ alcohol oxidation: CB11H12- • Extremely inert • Weakly coordinating • Low nucleophilicity • Large, charge-diffused • Synthesized in 3 steps • Derivatizable • Stabilizes “hot” cations THF oxidation catalysis: R u 1H NMR, CD3CN reaction in progress L N O [Ru]-cat. O L ' starting Cp* O new Cp* 2 starting Me product Me • References • Larsen, A. S., Holbrey J.D., Tham F.S., Reed C.A. J. Am. Chem. Soc.2000, 122, 7264--7272. • Jelíneck, T.; Baldwin, P.; Scheidt, R.W.; Reed, C.A. Inorg. Chem., 1993, 32, 1982--1990. • Jeljnek, T et al. Coll. Czech. Chem. Comm.1984, 49, ,p. 1559. • Chang, J.; Bergman, R. G. J. Am. Chem. Soc. 1987, 109, 4298-4304. • Chang, J.; Seidler, M. D.; Bergman, R. G. J. Am. Chem. Soc. 1989, 111, 3258-3271. • Brookhart, M.; Grant, B.; Volpe, A. F. Jr. Organometallics1992, 11, 3920-3922. • Rifat, A.; Kociok-Kohn, G.; Steed, J. W.; Weller, A. S. Organometallics2004, 23, 428-432 • Hlatky, G. G.; Eckman, R. R.; Turner, H. W. Organometallics 1992, 11, 1413-1416. • Hubbard, J. L.; Morneau, A.; Burns, R. M.; Zoch, C. R. J. Am. Chem. Soc. 1991, 113, 9176-9180. • Xie, Z; Jelinek, T.; Bau, R.; Reed, C. A. J. Am. Chem. Soc. 1994, 116, 1907-1913. • Acknowledgements • We are grateful to Dr. John D. Holbrey for a donation of imidazolium halides, to professor Christopher A. Reed for a donation of decaborane, to professor Geoff Coats for helpful suggestions. • Funding for summer internships to J.K, M.S, J.M., start-up funds and Faculty Development Award to A.L. were provided by Ithaca College and are gratefully acknowledged. carborane acid m.p. data Cp*Ru(NO)Me2 Effect of Anion on Melting Point protonation product n-HexPy hexabromo-CB -> solution IR (CD3CN) 1 NO region m.p. (°C) 2 3 (works!) R=H X=H R=Me X=H R=H X=Br *Super-cooling effects Effect of Cation on Melting Point <- n-butyl pyridinium carborane m.p. (°C) O O Derivatization: Carborane synthesis: R H - - C C 1 . n - B u L i ( > > 2 e q ' s ) B H B H H B B H H B B H N M e • H C l 2 . R - X ( X = C l , B r ) 3 B H B H + B H B H N M e H L i + 3 B H B H B H B H H O 2 H B B H H B B H B H B H B B H H Jesse Kleingardner, Matthew Pearsall, Joshua Masland, Anna S. Larsen Department of Chemistry, Ithaca College, Ithaca, NY 14850 Low-melting salts with carborane anion Electrophilic Cp*Ru(NO) paired with carborane • Ionic liquids (IL): • possess wide liquid temperature range • have virtually no vapor pressure • dissolve covalent and ionic compounds • can serve both as catalyst and solvent • advantageous for electrochemistry • Carborane-based IL: • need for non-reactive anion (instead of AlCl4-, PF6-, BF4-) • factors for low m.p. studies systematically through • varied derivatized anion and cation combinations • employ alkyl-pyridinium cations to compare to our earlier study • bis-alkyl-imidazolium carboaren salts • Cp*Ru(NO) piano-stool complexes • Accessible synthetically • NMR marker (Cp*) • IR marker (NO) • Electrophilic metal center Preliminary X-ray data From the X-ray facilities of the university of Alabama and University of Wisconsin n-BuPyCB m.p. 134 oC alkyne reactivity n-HexPy 1-MeCB m.p. 70oC Clean Protonation of [Ru]Me2 : Differential Scanning Calorimetery • Problems with reported systems: • OTf binds tightly to metal center, hampers • catalytic reactivity towards substrate • BAr4F disintegrates • Carborane analogs are not known Undergraduate Projects at Ithaca College: Carboranes for [RuCp*(NO)] Chemistry and Low-melting Ionics carried out the at the facilities of the Cornell University ether from carborane acid gas formation observed upon mixing (CH4) Synthetic routes to CB complex • Immediate and future plans: • Isolation and characterization • Reactivity studies with • Olefins • Alkynes • ROH • CO2 • H2O • On-going studies and plans: • Electrochemical studies in melts: ion mobility • X-ray studies • EPR studies for conductivity/viscosity • Synthesis of unsymmetrically halogenated CB • Synthesis of hydrophilic salts of derivatized CB