Spectroscopy — From insulator to semiconductor: effect of host-guest interactions on charge transport in M-MOF-74 metal-organic frameworks

6 measurement groups · 15 results

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

Diffuse reflectance spectroscopy (DRS)

UV-visible and optical absorption spectroscopy

TCNQ@Mn-MOF-74 film for DRS · Thin Film

DRS obtained with ASD Quality Spec Pro UV-Vis spectrometer with fibre optic mug light attachment; spectra scanned 350-2500 nm; Mn-MOF-74 films printed onto FTO-coated glass.

Geometry: Diffuse reflectance on printed FTO-supported film.
Context: Mn-MOF-74 before and after TCNQ infiltration.
Measurement source: S-5 · Characterization methods

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Mn-MOF-74 optical band gap before TCNQ	Optical band gap reported as 2.48 eV in the before/after TCNQ comparison.	—	—	Text Exact Reported	2700 · Results and discussion · Fig. 2c-d
TCNQ@Mn-MOF-74 optical band gap	Optical band gap reported as 1.46 eV in the before/after TCNQ comparison.	—	—	Text Exact Reported	2700 · Results and discussion · Fig. 2c-d
TCNQ@Mn-MOF-74 charge-transfer peak	Peak at 850 nm represents donor-acceptor charge transfer between Mn-MOF-74 and confined TCNQ.	—	—	Text Exact Reported	2700 · Results and discussion · Fig. 2d

Raman spectroscopy

H4TCNQ@Cu-MOF-74 pellet · Pellet

Raman spectra of Cu/Mn-MOF-74, H4TCNQ, and H4TCNQ@Cu/Mn-MOF-74.

Geometry: MOF solid.
Context: Hydrogenated guest controls.
Measurement source: S-8 · Raman Spectra · Fig. S4c-d

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
H4TCNQ Raman coordination evidence	Raman suggests H4TCNQ coordination to the OMS with a C-CN wing stretch shift and C=N stretch broadening.	—	—	Text Qualitative	2701 · Results and discussion · Fig. S4c-d

Raman spectroscopy

TCNQ@Mg-MOF-74 pellet · Pellet

Raman spectra of Mg-MOF-74, Zn-MOF-74, TCNQ, and TCNQ@Mg/Zn-MOF-74.

Geometry: MOF solid.
Context: Closed-shell TCNQ controls.
Measurement source: S-8 · Raman Spectra · Fig. S4a-b

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Raman coordination signals absent for Mg/Zn variants	Signals indicating TCNQ coordination are absent from Mg-MOF-74 and Zn-MOF-74.	—	—	Text Qualitative	2700 · Results and discussion · Fig. S4a-b

Raman spectroscopy

TCNQ@Cu-MOF-74 pellet · Pellet

Renishaw inVia Raman microscope; spectra between 1100-2400 cm-1, 10 accumulations, 532 nm laser excitation, about 50 microW at sample.

Geometry: MOF solid.
Context: Cu-MOF-74 before and after TCNQ infiltration.
Measurement source: 2700 · Results and discussion · Fig. 2a

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Estimated partial charge transfer from Raman	Partial charge transfer of about 0.3 e between framework and TCNQ.	—	—	Text Approximate	2700 · Results and discussion · Fig. 2a-b
C=N stretch indicating TCNQ coordination	C=N stretch at 2230 cm-1 indicates coordination of TCNQ molecule to the metal ion for Cu-MOF-74 and Mn-MOF-74.	—	—	Text Exact Reported	2700 · Results and discussion · Fig. 2a-b
C=C wing stretching red shift	A red shift of 19 cm-1 for the C=C wing stretching mode suggests partial charge transfer.	—	—	Text Exact Reported	2700 · Results and discussion · Fig. 2a-b
TCNQ C-CN wing stretch shift for Cu-MOF-74	C-CN wing stretch shifts by 114 cm-1 from 1462 to 1348 cm-1.	—	—	Text Exact Reported	2700 · Results and discussion · Fig. 2a

Raman spectroscopy

TCNQ@Mn-MOF-74 pellet · Pellet

Same Raman method; Mn-MOF-74 before and after TCNQ infiltration.

Geometry: MOF solid.
Context: Mn-MOF-74 before and after TCNQ infiltration.
Measurement source: 2700 · Results and discussion · Fig. 2b

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
TCNQ C-CN wing stretch shift for Mn-MOF-74	The same 114 cm-1 C-CN wing stretch shift occurs for Mn-MOF-74.	—	—	Text Exact Reported	2700 · Results and discussion · Fig. 2b

Transmission UV-Vis absorbance spectroscopy

UV-visible and optical absorption spectroscopy

TCNQ@Cu-MOF-74 pellet · Pellet

UV-Vis spectra collected on Shimadzu UV-3600 UV-VIS-NIR spectrophotometer; main text uses spectra to evaluate intermolecular charge transfer and band gap.

Geometry: Transmission optical geometry.
Context: Cu-MOF-74 before and after TCNQ infiltration.
Measurement source: 2700 · Results and discussion · Fig. 2c

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Cu-MOF-74 optical band gap before TCNQ	Optical band gap reported as 3.08 eV in the before/after TCNQ comparison.	—	—	Text Exact Reported	2700 · Results and discussion · Fig. 2c-d
TCNQ@Cu-MOF-74 optical band gap	Optical band gap reported as 1.88 eV in the before/after TCNQ comparison.	—	—	Text Exact Reported	2700 · Results and discussion · Fig. 2c-d
No oxidised TCNQ by-product band	No band at 480 nm corresponding to oxidised TCNQ by-product was observed after air-free infiltration.	—	—	Text Qualitative	2700 · Results and discussion · Fig. 2c-d
TCNQ@Cu-MOF-74 lower-energy absorption peak	New lower-energy absorption peak at 660 nm.	—	—	Text Exact Reported	2700 · Results and discussion · Fig. 2c
TCNQ@Cu-MOF-74 TCNQ monomer absorption band	Weaker absorption band at 800 nm originates from TCNQ monomer.	—	—	Text Exact Reported	2700 · Results and discussion · Fig. 2c