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Dougherty, D. A., Science, 1996, 271, 163. Red = most negative electrostatic potentials (most basic regions) Blue = most positive electrostatic potentials (most acidic regions). Dougherty et al., Proc. Natl. Acad. Sci. USA, Vol. 93, pp. 10566–10571, October 1996 Chemistry. OR. p base.
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Red = most negative electrostatic potentials (most basic regions) Blue = most positive electrostatic potentials (most acidic regions) Dougherty et al., Proc. Natl. Acad. Sci. USA, Vol. 93, pp. 10566–10571, October 1996 Chemistry
OR p base p acid Burini; Fackler; Omary; Staples et al. J. Am. Chem. Soc. 2000, 122, 11264-11265. TRHg
DFT Calculations of Trinuclear Complexes [Hg(C6F4)]3 [Au(bzim)]3 Electrost. Pot. (a.u.) -0.0300 0.0300
Electrostatic Potential Surfaces [Hg(C6F4)]3 green = positive [Au(bzim)]3 red = negative p-Electrostatic interaction
ADF Calculations {[Au(carb)]3}2 DIMER Green= positive Red=negative
SUPER WHOPPER!! p base p acid p base
SUPRAMOLECULAR CHAIN ASSEMBLIES p base p acid p base p acid Burini; Fackler; Omary; Staples et al. J. Am. Chem. Soc. 2000, 122, 11264-11265.
Solid-state example: p acid p base p acid p base p acid Phosphorescence at RT in the solid-state!! • = 568 ± 8 ms (RT)
Complexation of [Hg(o-C6F4)]3, 1, with aromatic hydrocarbons…RGB bright phosphorescent emissions for the 1:1 solid adducts Omary; Kassab; Haneline; Elbjeirami; Gabbai Inorg. Chem.2003, 42, 2176-2178.
t = 3.6 ms Au3(carb)3.octafluoronaphthalene p acid p base p acid p base
R= e-withdrawing (e.g., CF3) • makes it more of a p acid R= e-releasing (e.g., Me; i-Pr; t-Bu) makes it more of a p base M= Cu; Ag; Au Metal effect??…
DFT-calculated electrostatic potentials mapped on the electron density surfaces of M3Pz3 complexes. Color code: red=most negative= strong p base; blue=most positive= strong p acid; Yellow= neutral/weak p base green=neutral/weak p acid Cu3Pz3Ag3Pz3,Au3Pz3 Pz ligands here have R=Me groups on them all
All strongp acids But given previous slide we think that the Ag3 compound would be the strongest p acid Calculations done by Alex Gonser, as a CHEM5610 classroom project last year.
SUMMARY • Ligand effect: • R= e-withdrawing (e.g., CF3) • makes it more of a p acid • R= e-releasing (e.g., Me; i-Pr; t-Bu) • makes it more of a p base Metal effect: Relative p basicity: Au>Cu>Ag Relative p acidity: Ag>Cu>Au M= Cu; Ag; Au If you want to react with naphthalene (p base), what would you choose for R and M to form an acid-base adduct?
Maha Eldabaja (4610 student here doing research in the Omary group)….just got crystals of an adduct for [Ag(3,5-(CF3)2Pz)]3 with naphthalene and found that it has green emission, consistent with naphthalene phosphorescence
Maha Eldabaja (4610 student here doing research in the Omary group)….just got crystals of an adduct for [Ag(3,5-(CF3)2Pz)]3 with naphthalene and found that it has green emission, consistent with naphthalene phosphorescence (let’s hear it for Maha!!) Chi2 : 1.032 Durbin Watson : 1.85 Z : 374.2 Pre-exp. 1 : 825.2 ±1.638E+001 Lifetime 1 : 1.575E+004 ms±6.652E+002 Offset : 26.5 t = ~ 16 ms