Computational Modelling — Superexchange Charge Transport in Loaded Metal Organic Frameworks

Measurement evidence

Computational Modelling

Superexchange Charge Transport in Loaded Metal Organic Frameworks · Neumann T., Liu J., Wachter T. et al. · ACS Nano · 2016 · 7085-7093

6 measurement groups · 35 results

Reported values remain attached to the sample, method, conditions, extraction quality and source location that produced them.

Quantum Patch / Loewdin orthogonalisation electronic couplings and Nelsen four-point reorganisation energies

TCNQ/HKUST-1 computational model · Model

Electronic coupling matrix elements and reorganisation energies for HOMO and LUMO transport pathways in TCNQ/F4-TCNQ loaded HKUST-1.

Context
model parameter table for loaded HKUST-1 transport
Measurement source
7087 · Results and Discussion · Table 1
PropertyReported valueNormalised valueUncertaintyOrigin and qualitySource
Activation energy for guest-guest hopping67 meV0.067 eV—Text
Exact Reported
7087 · Results and Discussion · Table 1
F4-TCNQ HOMO reorganisation energy lambda0.166 eV——Table
Exact Reported
7087 · Results and Discussion · Table 1
F4-TCNQ LUMO reorganisation energy lambda0.271 eV——Table
Exact Reported
7087 · Results and Discussion · Table 1
MOF HOMO reorganisation energy lambda0.664 eV——Table
Exact Reported
7087 · Results and Discussion · Table 1
MOF LUMO reorganisation energy lambda0.580 eV——Table
Exact Reported
7087 · Results and Discussion · Table 1
TCNQ HOMO reorganisation energy lambda0.129 eV——Table
Exact Reported
7087 · Results and Discussion · Table 1
TCNQ LUMO reorganisation energy lambda0.266 eV——Table
Exact Reported
7087 · Results and Discussion · Table 1
LUMO F4-TCNQ-F4-TCNQ orthogonal coupling J2.0 x 10^-8 eV——Table
Exact Reported
7087 · Results and Discussion · Table 1
LUMO F4-TCNQ-F4-TCNQ parallel coupling J5.0 x 10^-9 eV——Table
Exact Reported
7087 · Results and Discussion · Table 1
LUMO F4-TCNQ-MOF coupling J2.4 x 10^-3 eV——Table
Exact Reported
7087 · Results and Discussion · Table 1
LUMO MOF-MOF first-nearest-neighbour coupling J5.7 x 10^-2 eV——Table
Exact Reported
7087 · Results and Discussion · Table 1
LUMO MOF-MOF second-nearest-neighbour coupling J3.0 x 10^-5 eV——Table
Exact Reported
7087 · Results and Discussion · Table 1
LUMO TCNQ-MOF coupling J1.4 x 10^-3 eV——Table
Exact Reported
7087 · Results and Discussion · Table 1
LUMO TCNQ-TCNQ orthogonal coupling J1.7 x 10^-8 eV——Table
Exact Reported
7087 · Results and Discussion · Table 1
LUMO TCNQ-TCNQ parallel coupling J4.1 x 10^-9 eV——Table
Exact Reported
7087 · Results and Discussion · Table 1

DFT geometry optimisation in Turbomole; B3-LYP XC functional, SV(P) basis, dispersion correction disp3

F4-TCNQ/HKUST-1 computational model · Model

HKUST-1 subsets fixed during guest geometry optimisation; three binding configurations evaluated.

Context
F4-TCNQ/HKUST-1 model
Measurement source
S12 · 3.1 Calculation of the binding mechanism · Figure S9
PropertyReported valueNormalised valueUncertaintyOrigin and qualitySource
F4-TCNQ binding energy, configuration aMarked as a best value within this paper-1.84 eV per molecule in SI; main text says -1.82 eV—main/SI discrepancy: -1.82 vs -1.84 eVText
Rounded Reported
S12 · 3.1 Calculation of the binding mechanism · Figure S9
Energy advantage of preferred F4-TCNQ configuration0.66 eV——Caption
Exact Reported
7087 · Results and Discussion · Figure 2
F4-TCNQ binding energy, configuration b-0.91 eV per molecule——Text
Exact Reported
S12 · 3.1 Calculation of the binding mechanism · Figure S9
F4-TCNQ binding energy, configuration c-1.18 eV per molecule——Text
Exact Reported
S12 · 3.1 Calculation of the binding mechanism · Figure S9

DFT geometry optimisation in Turbomole; B3-LYP XC functional, SV(P) basis, dispersion correction disp3

TCNQ/HKUST-1 computational model · Model

HKUST-1 subsets fixed during guest geometry optimisation; three binding configurations evaluated.

Context
TCNQ/HKUST-1 model
Measurement source
S12 · 3.1 Calculation of the binding mechanism · Figure S9
PropertyReported valueNormalised valueUncertaintyOrigin and qualitySource
TCNQ binding energy, configuration aMarked as a best value within this paper-1.97 eV per molecule——Text
Exact Reported
S12 · 3.1 Calculation of the binding mechanism · Figure S9
Energy advantage of preferred TCNQ configuration0.72 eV——Caption
Exact Reported
7087 · Results and Discussion · Figure 2
TCNQ binding energy, configuration b-0.99 eV per molecule——Text
Exact Reported
S12 · 3.1 Calculation of the binding mechanism · Figure S9
TCNQ binding energy, configuration c-1.25 eV per molecule——Text
Exact Reported
S12 · 3.1 Calculation of the binding mechanism · Figure S9

Injection-current model fitted to experimental current densities and KMC mobility

Pristine HKUST-1 SURMOF, 5 spray cycles · Thin Film

Device thicknesses 44.7 nm for pristine and F4-TCNQ-loaded MOF and 33.0 nm for TCNQ-loaded MOF; loaded/pristine current-density ratios averaged.

Geometry
Hg-drop vertical junction data converted for injection model
Context
experimental-model comparison for pristine and guest-loaded SURMOFs
Measurement source
S16 · 3.6 Model for injection current · Figure 6
PropertyReported valueNormalised valueUncertaintyOrigin and qualitySource
Inferred LUMO-level difference between pristine and loaded MOFaround 0.6 eV—aroundText
Approximate
7091 · Results and Discussion · Figure 6
F4-TCNQ mobility-curve intersection / inferred LUMO differenceapproximately 0.62 eV—approximatelyCaption
Approximate
7091 · Results and Discussion · Figure 6
TCNQ mobility-curve intersection / inferred LUMO differenceapproximately 0.71 eV—approximatelyCaption
Approximate
7091 · Results and Discussion · Figure 6
Difference in injection barriers between F4-TCNQ- and TCNQ-loaded MOFroughly 0.1 eV—roughlyText
Approximate
7091 · Results and Discussion · Figure 6
KMC mobility of empty HKUST-1 used in injection model1.25 x 10^-3 cm2/Vs——Text
Exact Reported
S16 · 3.6 Model for injection current · Figure 6

Marcus rates plus kinetic Monte Carlo simulations

TCNQ/HKUST-1 computational model · Model

Five configurational disorder models; ten independent KMC simulations per model; 20 electrons injected; applied external electric field 0.035 V/nm.

Geometry
bulk KMC model
Context
electron transport in guest-loaded HKUST-1
Measurement source
S15-S16 · 3.5 Kinetic Monte Carlo · Figure 3; Figure 6
PropertyReported valueNormalised valueUncertaintyOrigin and qualitySource
Direct-process activation energy when DeltaEgh > 0.4 eVEa is much larger than 0.42 eV—lower-bound statementText
Approximate
7087 · Results and Discussion · Figure S11
Estimated F4-TCNQ LUMO shift relative to TCNQ0.6 eV—estimated at least 0.6 eVCaption
Approximate
7088 · Results and Discussion · Figure 3c
Applied field in KMC simulations0.035 V/nm——Text
Exact Reported
S16 · 3.5 Kinetic Monte Carlo
Electron mobility enhancement from superexchangeup to 5 orders of magnitude larger than first-order processes——Caption
Approximate
7088 · Results and Discussion · Figure 3c
Approximate loading/percolation threshold for qualitative guest difference~35% of the sites0.35 fraction of sitesapproximatelyText
Approximate
7091 · Results and Discussion
Estimated guest-host site energy difference thresholdDeltaEgh > 0.4 eV for both guest molecules—treated as a parameter due to DFT uncertaintyText
Approximate
7087 · Results and Discussion · Figure 3

Marcus rates plus kinetic Monte Carlo simulations for holes

TCNQ/HKUST-1 computational model · Model

Hole hopping rates and mobilities calculated analogously to electron case; compared with pristine HKUST-1 mobility.

Geometry
bulk KMC model
Context
hole transport in guest-loaded HKUST-1
Measurement source
S16-S17 · 3.7 Hole transport simulations · Figure 3d,e
PropertyReported valueNormalised valueUncertaintyOrigin and qualitySource
Maximum hole mobility increase upon loadingup to one order of magnitude only for DeltaE close to zero—qualitative energy-window statementCaption
Approximate
7088 · Results and Discussion · Figure 3e