Download
ion and neutral thermochemistry from the gas to solution phase an overview n.
Skip this Video
Loading SlideShow in 5 Seconds..
Ion and Neutral Thermochemistry from the Gas to Solution Phase an overview PowerPoint Presentation
Download Presentation
Ion and Neutral Thermochemistry from the Gas to Solution Phase an overview

Ion and Neutral Thermochemistry from the Gas to Solution Phase an overview

77 Views Download Presentation
Download Presentation

Ion and Neutral Thermochemistry from the Gas to Solution Phase an overview

- - - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

  1. Mesilla Workshop on Organometallic Chemistry - 2006 Ion and Neutral Thermochemistryfrom the Gas to Solution Phasean overview Tomas Baer University of North Carolina Chapel Hill, NC

  2. M+ + 2L Ion and Neutral thermochemistry – Gas Phase Armentrout ML+ + L Armentrout Known IE(M) Baer Sztáray ML2+ Baer Sztáray Yang Sztáray Lichtenberger Yang M + 2L ML + L Derived ML2

  3. IEad ? Uncertainty = 0.10eV (10 kJ/mol) Electron Energy Uncertainty = 0.01eV (1 kJ/mol) IEad Electron Energy Ionization Energy Measurements Hion IEad IEad Room Temperature PES Molecular beam cooling – laser ionization

  4. Thermal energy and Breakdown Diagram No worries about FC factors TPEPICO experiment E -h v o + P P+ h v Fractional Abundance Eo± 10 meV (1 kJ/mol) + AB Eo E o D+ Eo-hv P(E) Photon energy (hv) AB Known thermal energy distribution

  5. Dissociation Onset Measurements Collisional Dissociation - Armentrout AB++ M  A+ + B + M E0 ± 50 meV (5 kJ/mol) A+ signal A++ B Hdis Collision energy (eV) E0 Again, no worries about FC factors. But there are other worries such as dissociation rate constants. AB+

  6. (C6H6)2Cr Breakdown diagram Eint(Bz) + Etrans BzCrBz+ CrBz+ + Bz  Cr+ + 2 Bz CrBz+ + Bz BzCrBz+ hv BzCrBz Li and Baer, J. Phys. Chem. A. 106 9820-9826 (2002)

  7. Energy partitioning in dissociation E-E0 Ei E E0 PEt3+ HPEt2+ + C2H4 Need only product vibrational frequencies. No adjustable parameters involved.

  8. (C6H6)2Cr Energetics Cr 4s 3d 3d 3d 3d 3d 5.465eV Measured IE (laser spectrosc.) D.S. Yang (unpublished) Measured IE (laser spectrosc.) Kurikawa et al. (1999) Organometallics18, 1430

  9. Theory: Chris Cramer; Tom Ziegler; Mu-Hyun Baik transient IR spectroscopy Eric Weitz Solvation Effects in neutral organometallic complexes MLn-1 + L MLn-1 BE[M-S(g)] SMLn-1 SE(SMLn-1 + L) SMLn-1S + LS MLn-1 + L BE[M-L(g)] fHo CID, PEPICO, PES Baer/Sztáray/ArmentroutLichtenberger/Yang photoacoustic calorimetry Ted Burkey & Joe Grabowski BE[M-L(s)] MLn(g) SE(MLn) MLn MLnS Gas Phase Solution Phase