Eighth Condensed Phase and Interfacial Molecular Science (CPIMS)

More documents

Recommendations

Info

framework to allow for more general exploration of the phenomena and driving forces involved in TDF experiments, and chemistry in general, in nanoconfined solvents. We have calculated the free energy for a Stock- mayer-type solute as a function of position in atomistic silica pores, using different solute dipole moments; 8 see Fig. 2. We found that the electrostatic interactions with the pore interface led to a dependence of the solute position distribution on the solute dipole. Moreover, in hydrophilic silica pores the fluorescence spectrum depends on the solute position. These results indicate that solute diffusion may contribute to the TDF signal and, more generally, that it will be a component of the mechanism for a number of chemical processes in nano confined solvents. The fact that this effect originates with the solute-pore interactions further suggests that the confining framework can Free Energy, ∆A(x) (kJ/mol) 25 20 15 10 5 5 D 10 D 0 -10 -8 -6 -4 -2 0 2 4 6 8 Solute Position, x (Å) Figure 2: Free energy, ∆A(x), as a function of solute position along a slice across an ethanol-filled hydrophilic silica pore for a 5 D (blue) and 10 D (red) Stockmayer-type solute. be tuned to affect the chemistry of the confined liquid. Ongoing work includes comparing solvation dynamics in nanoconfined solvents with those at planar silica surfaces to separate interfacial and confinement effects and make better connections with experimental measurements. We are also exploring how the TDF response depends on the dye molecule properties and how this might be exploited to elucidate the solvation mechanism through multiple measurements with different dyes. We have also examined the accuracy of linear-response and Gaussian statistics approximations for describing solvation dynamics generally and in nanoconfined solvents. 4 We have found that the dynamical linear-response approximation fails to describe the TDF signal in model nanoconfined solvent systems, while the assumption of Gaussian statistics gives quite accurate results. 4 We further investigated the differences between the static linear-response and Gaussian statistics approximations and found that the latter is the natural interpretation of excited-state equilibrium correlation functions. Finally, we showed how the Gaussian statistics approximation provides ways to test its accuracy based solely on equilibrium correlation functions. We are examining linear response approximations in more complex nanoconfined solvent systems, e.g., silica pores, as well as testing the Gaussian statistics approximation and related insights for traditional models that exhibit linear-response violations. Proton Transfer (PT). We have been continuing our work on proton transfer reactions in nanoconfined solvents 2, 3, 6 by investigating approaches to more generally sample the reaction coordinate, both to identify transition state configurations and simulate infrared spectra. 6 Specifically, we have used an umbrella sampling approach based on the proton vibrational energy gap. This exploits the fact that for a PT reaction the energy gap between the vibrational ground and excited states of the transferring proton reaches a minimum at the transition state. We have implemented this umbrella sampling within mixed quantum-classical simulations to identify the transition state configurations and explore the reaction free energy curve and vibrationally nonadiabatic coupling. We have tested this 181
approach on a model phenol-amine proton transfer reaction complex in a solvent confined within a hydrophobic nanoscale cavity. 6 This sampling approach provides a direct and efficient way to calculate vibrational spectra and nonadiabatic couplings. DOE-Supported Publications (2009 – present) [1] X. Feng and W.H. Thompson, J. Phys. Chem. C 114, 4279-4290 (2010). “Time-dependent Fluorescence in Nanoconfined Solvents. A Smoluchowski Equation Model Study” [2] B.J. Ka and W.H. Thompson, J. Phys. Chem. B 114, 7535-7542 (2010). “Nonadiabatic Effects on Proton Transfer Rate Constants in a Nanoconfined Solvent” [3] W.H. Thompson, Annu. Rev. Phys. Chem. 62, 599-619 (2011). “Solvation Dynamics and Proton Transfer in Nanoconfined Liquids” [4] B.B. Laird and W.H. Thompson, J. Chem. Phys. 135 084511 (2011). “Time-Dependent Fluorescence in Nanoconfined Solvents: Linear Response Approximations and Gaussian Statistics” [5] A.A. Vartia, K.R. Mitchell-Koch, G. Stirnemann, D. Laage, and W.H. Thompson, J. Phys. Chem. B 115, 12173-12178 (2011). “On the Reorientation and Hydrogen-Bond Dynamics of Alcohols” [6] B.J. Ka and W.H. Thompson, J. Phys. Chem. A 116, 832-838 (2012). “Sampling the Transition State of a Proton Transfer Reaction in Mixed Quantum-Classical Molecular Dynamics Simulations” [7] D. Laage and W.H. Thompson J. Chem. Phys. 136, 044513 (2012). “Reorientation Dynamics of Nanoconfined Water: Power-law Decay, Hydrogen-bond Jumps, and Test of a Two-State Model” [8] A.A. Vartia and W.H. Thompson, J. Phys. Chem. B 116, 5414-5424 (2012). “Solvation and Spectra of a Charge Transfer Solute in Nanoconfined Ethanol” 182
Page 1 and 2:
Eighth Condensed Phase and Interfac
Page 3 and 4:
Potential energy landscape of the (
Page 5 and 6:
Agenda
Page 7 and 8:
Session III Chair: Jay A. LaVerne,
Page 9 and 10:
Table of Contents
Page 11 and 12:
Transition Metal-Molecular Interact
Page 13 and 14:
Ultrafast Electron Transport across
Page 15 and 16:
CPIMS Principal Investigator Abstra
Page 17 and 18:
VUV LDPI image of a polymer photore
Page 19 and 20:
Publications based on DOE support (
Page 21 and 22:
entirely quenched, presumably due t
Page 23 and 24:
Future Plans In addition to the TiO
Page 25 and 26:
The relative path indexes of the ur
Page 27 and 28:
We have recently carried out molecu
Page 29 and 30:
have been obtained with γ-rays sug
Page 31 and 32:
Two novel plasma devices have been
Page 33 and 34:
(Figure 2) can be adsorbed exclusiv
Page 35 and 36:
3. Future Plans Our planned work de
Page 37 and 38:
Figure 1: Snap shots from molecular
Page 39 and 40:
6. Varilly, P., A. J. Patel and D.
Page 41 and 42:
hypothesis that delocalized charges
Page 43 and 44:
Efforts will be made to observe ele
Page 45 and 46:
Photochemistry and Solvation Dynami
Page 47 and 48:
complementary to work we have carri
Page 49 and 50:
The Co3O4 films for the optical pum
Page 51 and 52:
chamber will allow us to heat the s
Page 53 and 54:
calculations. Additional PMF calcul
Page 55 and 56:
the gas solute first needs to cross
Page 57 and 58:
laser system, which is an infrared
Page 59 and 60:
Publications (10/1/2009-present) fo
Page 61 and 62:
interest are: (i) What is the diffu
Page 63 and 64:
and anilino groups attached to the
Page 65 and 66:
had been formed. This coincides wit
Page 67 and 68:
Figure 1. (A) Simplified bR photocy
Page 69 and 70:
Figure 4. Photocurrent density of b
Page 71 and 72:
single-file diffusion and cannot ca
Page 73 and 74:
PUBLICATIONS SUPPORTED BY USDOE CHE
Page 75 and 76:
arrangement. However, the hydrogen
Page 77 and 78:
(5) “Water Dynamics in Salt Solut
Page 79 and 80:
from high- energy x-ray diffraction
Page 81 and 82:
concentrated aqueous solutions. The
Page 83 and 84:
molecule’s center of mass, or alt
Page 85 and 86:
Moreover, SHG studies by Saykally
Page 87 and 88:
The effective fragment potential (E
Page 89 and 90:
10. D.D. Kemp, J. Rintelman, M.S. G
Page 91 and 92:
temperature dependent, equilibrium
Page 93 and 94:
mimicking real organic photovoltaic
Page 95 and 96:
100 kHz amplifier, SE-FSRS was succ
Page 97 and 98:
photovoltaics will be explored via
Page 99 and 100:
for laser surface reactions to thes
Page 101 and 102:
This is a significant advantage of
Page 103 and 104:
the STM, which might underlie the u
Page 105 and 106:
Future Plans: Figure 3. One and two
Page 107 and 108:
methane molecule and a lattice atom
Page 109 and 110:
eactive than the Ni, experiment sug
Page 111 and 112:
Fig. 1. PE spectra of M3Oy � (M =
Page 113 and 114:
each of the intermediates obtained
Page 115 and 116:
a regime where each solvent molecul
Page 117 and 118:
observables that arise from subtle
Page 119 and 120:
total potentials. One can see from
Page 121 and 122:
Our calculations have shown that ch
Page 123 and 124:
our understanding of structure and
Page 125 and 126:
viscosity, η, are inversely relate
Page 127 and 128:
photodissociation of the metal - NO
Page 129 and 130:
from a Ru 2p3/2 orbital to an orbit
Page 131 and 132:
Integrated O 2 PSD (ML) Integrated
Page 133 and 134:
anisotropy in the structure of the
Page 135 and 136:
XPS studies have been performed on
Page 137 and 138:
Publications with BES support since
Page 139 and 140:
MLCT (metal to ligand charge transf
Page 141 and 142:
molecule-metal interface without a
Page 143 and 144:
observe the predicted effects, whic
Page 145 and 146: (4*) Lymar, S. V.; Schwarz, H. A. J
Page 147 and 148: (τ .820 ns), but we have not been
Page 149 and 150: B. Photodissociation spectroscopy o
Page 151 and 152: oth BLYP and PBE. Our results have
Page 153 and 154: Publications from BES support (2010
Page 155 and 156: understanding of factors that contr
Page 157 and 158: Our talk will discussion our initia
Page 159 and 160: Figure 1 shows the band structure o
Page 161 and 162: likely to also occur in low coordin
Page 163 and 164: These results are promising indicat
Page 165 and 166: This page is intentionally left bla
Page 167 and 168: method recently developed by Prende
Page 169 and 170: and coordination regions. A differe
Page 171 and 172: two ions I - [3] and IO3 - [7]. One
Page 173 and 174: "Probing the Hydration Structure of
Page 175 and 176: world-wide scientific user base sup
Page 177 and 178: 10) C. Zhang, M.E. Grass, A.H. McDa
Page 179 and 180: produce the nanoparticles needed fo
Page 181 and 182: step as a symmetry-breaking templat
Page 183 and 184: work provides what we believe in th
Page 185 and 186: Selected publications acknowledging
Page 187 and 188: 2. Optical Stark study of PtF (Acce
Page 189 and 190: Figure 4. The Q(3.5) line of the [1
Page 191 and 192: In marked contrast to the selective
Page 193 and 194: y depositing cobalt onto copper sin
Page 195: Carlo calculations, we have carried
Page 199 and 200: We performed pump-probe experiments
Page 201 and 202: 15. “A phenomenological approach
Page 203 and 204: may be initially produced in a non-
Page 205 and 206: 4. Inelastic scattering of hydrogen
Page 207 and 208: Using QM/MM free energy methods we
Page 211 and 212: gas phase using electrospray ioniza
Page 215 and 216: order of Li + > Na + > K + for comp
Page 217 and 218: 2. MM Meyer, XB Wang, CA Reed, LS W
Page 219 and 220: Technical Approach and Progress to
Page 223 and 224: Ionic liquid synthesis and characte
Page 225 and 226: Studies of structure and reaction d
Page 227 and 228: structure theory that include elect
Page 229 and 230: 9. S. Pandelov, J. C. Werhahn, B. M
Page 231 and 232: pulse duration is a few times longe
Page 233 and 234: Figure 1 (Left) The HOMO and LUMO e
Page 235 and 236: slightly preferable in energy, the
Page 237 and 238: Participant List Dr. Musahid Ahmed
Page 239 and 240: Professor Kenneth Eisenthal Columbi
Page 241 and 242: Dr. Ireneusz Janik Notre Dame Radia
Page 243 and 244: Professor Eric Potma University of
Page 245: Dr. James Wishart Brookhaven Nation
show all

Eighth Condensed Phase and Interfacial Molecular Science (CPIMS)

Create successful ePaper yourself

Delete template?

Save as template?