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Actinide Metal Atom (Th and U) Reactions to Form Novel Molecules

Actinide Metal Atom (Th and U) Reactions to Form Novel Molecules. Metal-Carbon Multiple Bonds Actinide Metal Hydrides Lester Andrews, Chemistry Department, University of Virginia, Charlottesville, Virginia Also Jon Lyon, Han-Gook Cho, Xuefeng Wang,

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Actinide Metal Atom (Th and U) Reactions to Form Novel Molecules

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  1. Actinide Metal Atom (Th and U) Reactions to Form Novel Molecules Metal-Carbon Multiple Bonds Actinide Metal Hydrides Lester Andrews, Chemistry Department, University of Virginia, Charlottesville, Virginia Also Jon Lyon, Han-Gook Cho, Xuefeng Wang, Bjorn Roos, Han-shi Hu, Jun Li, Colin Marsden, Laura Gagliardi

  2. Apparatus for Laser Ablation and Matrix Isolation CsI window for IR

  3. YAG laser ablation of Zr

  4. Novel Organometallic Molecules M + CH4 CH3—MH ↔ CH2=MH2↔ HC≡MH3 M + CH3X  CH3—MX ↔ CH2=MHX ↔ HC≡MH2X M + CH2X2 CH2X—MX  CH2=MX2 HC≡MHX2 M + CHX3 CHX2—MX  CHX=MX2 HC≡MX3 M + CX4 CX3—MX  CX2=MX2 XC≡MX3

  5. B3LYP density functional calculated structures for methylidene molecules

  6. Infrared spectra of the Th + CH4 reaction productJ. Phys. Chem. A 2005, 105, 6796. Anneal 26 K > 220 nm 240-380 nm > 420 nm Dep at 7 K

  7. Observed and Calculated (B3LYP/6-311++G(3df,3pd)/SDD) Frequencies for CH2=ThH2

  8. CH2=ThH2, CH2=ThHF, CH2=UH2, CH2=UHF CH2=UHF CH2=ThHF

  9. Structures calculated with different theoretical methodsInorg. Chem. 2007, 46, 4917.BPW91/PW91/CASPT2

  10. One singly-occupied U 5f orbital in CH2=UH2

  11. Reactions of laser-ablated U atoms with CH2XY (XY = F2, FCl, and Cl2) lead to a series of new actinide methylidene complexes CH2=UF2, CH2=UFCl, and CH2=UCl2, which have agostic structures stabilized by interaction through the open-shell U 6d-5f orbitals.Angew. Chem. Intl. Ed. 2007, 46, 9045.

  12. Structures for Th, U and NH3 Reaction ProductsChem. Eur. J. 2007, 13, 5601.B3LYP/CCSD

  13. 1.951 1.903 H-N=ThH2 H-N=UH2 62.1% d 30.1% f 46.2% d 48.5% f HOMO HOMO 2.103 2.045 CH2=ThH2 CH2=UH2 Small amount of triple bond character

  14. Novel Organometallic Molecules M + CH4 CH3—MH ↔ CH2=MH2↔ HC≡MH3 M + CH3X  CH3—MX ↔ CH2=MHX ↔ HC≡MH2X M + CH2X2 CH2X—MX  CH2=MX2 HC≡MHX2 M + CHX3 CHX2—MX  CHX=MX2 HC≡MX3 M + CX4 CX3—MX  CX2=MX2 XC≡MX3

  15. Th atom reactions with CHF3, CHF2Cl, CHFCl2, and CHCl3 CHF3

  16. Observed and Calculated Fundamental Frequencies for HC÷ThF3 in C3v Symmetry in the Triplet Ground Electronic State Eur. J. Inorg. Chem. 2008, in press.

  17. Energies of Th and U atom reactions with CHF3 and CF4 • 2.48 Å2.16 Å 2.41 Å 2.13 Å 1.94 Å CHF2--ThF  CHF=ThF2 HC—ThF3 CHF=UF2  HC≡UF3 +76 kcal/mol + 46 kcal/mol 0 kcal/mol + 23 kcal/mol 0 kcal/mol 2.26 Å 2.47 Å 2.40 Å CF2=ThF2  CF2—ThF2  FC—ThF3 + 51 kcal/mol + 51 kcal/mol 0 kcal/mol 2.45 Å 2.40 Å 2.01 Å CF2—UF2  CF2=UF2  FC≡UF3 + 21 kcal/mol + 20 kcal/mol 0 kcal/mol

  18. B3LYP Structures for HC-ThX3 and XC-ThX3 Complexes

  19. Uranium atom reaction productsProc. Natl. Acad. Sci. 2007, 104, 18919. U + CF4 U+CF4 U + CDF3 U + CDF3 U+CDF3 U + CHF3

  20. Observed and calculated (PW91/TZ2P)fundamental vibrational frequencies for the C3vF3U≡CX (X = H, D, F) molecules

  21. Calculated structures of (a) F3U≡CH, (b) Cl3U≡CH, (d) Br3U≡CH, and (d) F3U≡CF

  22. Comparison of the molecular orbitals of ethyne HC≡CH and the uranium-methylidyne F3U≡CH and F3U≡CF complexes (isosurface =0.05 atomic unit)

  23. Uranium atom reaction products CHBr3 CDCl3 13CHCl3 CHCl3

  24. Observed and calculated (PW91/TZ2P)fundamental vibrational frequencies for the C3vX3U≡CH (X = Cl, Br) molecules

  25. Carbon-Uranium Triple Bonds • 1.764 Å1.808 Å 1.910 Å • C≡U≡OHC≡UCl3 • PW91 bond lengths • Zhou, Andrews, Li, Bursten, Lyon, Hu, Andrews, Li, • J. Am. Chem. Soc. 1999, 121, 9712. Proc. Natl. Acad. Sci. U.S. • Earlier work: 2007, 104(48), 18919. • Tague, Andrews, Hunt, • J. Phys. Chem. 1993, 97, 10920. • Pyykko, Li, Runeberg, • J. Phys. Chem. 1994, 98, 4809.

  26. Reactions of Mo atoms with CHX3 molecules: HC≡MoX3

  27. Reactions of Mo atoms with CHX3 moleculesOrganometallics, 2007, 26, 6373. Natural Mo isotopic splittings CHCl3 CHFCl2 CHF2Cl CHF3

  28. Observed and Calculated [B3LYP/6-311++G(2d,p) ] Fundamental Frequencies of HC≡MoX3 Complexes in the Ground 1A1 Electronic State with the C3v Structure

  29. Span the periodic table U + H2

  30. U in solid para-hydrogen at 4 KJ. Phys. Chem. A, 2007, 111, 6383.

  31. Th in solid H2, HD, and D2 at 4 KJ. Phys. Chem. A, 2008, in press.

  32. Ground statetotal CASSCF electron density WH4 (triplet) ThH4(singlet) UH4(triplet) WH44H2 (singlet) ThH44H2(singlet) UH46H2(triplet)

  33. Ball Game!!! • We have investigated reactions of the laser-ablated actinide metal atoms Th and U with small molecules, and assigned the new reaction products from matrix infrared spectra and comparison with DFT calculated isotopic frequencies. These new molecules are important for their unique bonding and structure and their unusual chemistry. • We thank NSF for support and you for your kind attention.

  34. PERSPECTIVE Theory Gas-Phase Matrix-Isolation Spectroscopy Synthesis

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