Spectroscopy — Generation of Environmentally Persistent Free Radicals on Metal-Organic Frameworks

11 measurement groups · 37 results

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

DRIFTS during dehydration/heating

Infrared spectroscopy

MIL-100(Al) powder · Powder

MIL-100 samples heated at 150 C or 250 C under Ar; OH/H2O stretching region monitored.

Atmosphere: Ar
Context: pristine and guest-loaded framework family
Measurement source: 3268 · Radical Generation on MIL-100(Al) · Figure 2b; Figures S6-S9, S22-S23

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Al-OH band after 250 C treatment	3580 cm-1	—	—	Text Exact Reported	3268 · Radical Generation on MIL-100(Al) · Figure 2b
Al-bound isolated water band	3674 cm-1	—	—	Text Exact Reported	3268 · Radical Generation on MIL-100(Al) · Figure S6
Cr MIL-100 water vibration attenuation	3668/3670 cm-1	—	—	Text Exact Reported	3271 · Radical Generation in MIL-100(Cr) and MIL-100(Fe) · Figure S23
Fe MIL-100 water vibration attenuation	about 3655 cm-1	—	approximate	Text Approximate	3271 · Radical Generation in MIL-100(Cr) and MIL-100(Fe) · Figure 4a; Figure S22

EPR ageing and pseudo-first-order decay fit

Electron paramagnetic resonance

CT-dosed MIL-100(Al) · Powder

CT-dosed MIL-100(Al) aged in ambient atmospheric environment.

Atmosphere: ambient air
Context: guest-loaded Al framework
Measurement source: 3270 · Radical Evolution in MIL-100(Al) · Figure S20

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
CT-related radical half-lifeMarked as a best value within this paper	187 days	—	—	Text Rounded Reported	3270 · Radical Evolution in MIL-100(Al) · Figure S20
CT-related spin density at start of ageing window	8.3 x 10^14 spins mm-3	—	—	Text Rounded Reported	3270 · Radical Evolution in MIL-100(Al) · Figure S20
CT-related spin density after 143 days	6.0 x 10^14 spins mm-3	—	—	Text Rounded Reported	3270 · Radical Evolution in MIL-100(Al) · Figure S20

Electron paramagnetic resonance (EPR), Bruker E500 X-band

Electron paramagnetic resonance

CT-dosed MIL-100(Al) · Powder

Room-temperature EPR after CT exposure and 250 C thermal treatment.

Atmosphere: ambient during measurement
Context: guest-loaded Al framework
Measurement source: S14 · Supporting figures and tables · Figure S11

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
CT-dosed MIL-100(Al) EPR g-valueMarked as a best value within this paper	2.0040	—	—	Text Exact Reported	3269 · Radical Generation on MIL-100(Al) · Figure S11
CT-dosed MIL-100(Al) EPR peak width	11.4 G	—	—	Text Exact Reported	3269 · Radical Generation on MIL-100(Al) · Figure S11
CT-dosed radical concentration after solvent extractionMarked as a best value within this paper	1.7 x 10^18 spins/g	—	—	Text Rounded Reported	3269 · Radical Generation on MIL-100(Al) · Figure S15
CT-dosed radical concentration before solvent extraction	4.5 x 10^18 spins/g	—	—	Text Rounded Reported	3269 · Radical Generation on MIL-100(Al) · Figure S15

EPR ageing and pseudo-first-order decay fit

Electron paramagnetic resonance

MCP-dosed MIL-100(Al) · Powder

MCP-dosed MIL-100(Al) aged in ambient atmospheric environment from day 10 to day 157.

Atmosphere: ambient air
Context: guest-loaded Al framework
Measurement source: 3270 · Radical Evolution in MIL-100(Al) · Figure 3e-f; Table S3

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
MCP-dosed MIL-100(Al) aged 157 days g-factor	2.0044	—	—	SI Table Exact Reported	S24 · Supporting figures and tables · Table S3
MCP-dosed MIL-100(Al) aged 157 days peak width	8.3 Gauss	—	—	SI Table Exact Reported	S24 · Supporting figures and tables · Table S3
MCP radical decay regression coefficient	0.98	—	—	Text Exact Reported	3270 · Radical Evolution in MIL-100(Al) · Figure 3f
MCP-involved radical half-lifeMarked as a best value within this paper	70 days	—	—	Text Rounded Reported	3270 · Radical Evolution in MIL-100(Al) · Figure 3f
MCP-involved radical 1/e lifetime	101 days	—	—	Text Rounded Reported	3270 · Radical Evolution in MIL-100(Al) · Figure 3f

Electron paramagnetic resonance (EPR), Bruker E500 X-band

Electron paramagnetic resonance

MCP-dosed MIL-100(Al) · Powder

Room-temperature EPR after MCP exposure and 250 C thermal treatment; typical settings 9.85 GHz, 0.1002 mW, 100 kHz modulation.

Atmosphere: ambient during measurement
Context: guest-loaded Al framework
Measurement source: 3267 · Electron Paramagnetic Resonance (EPR) Measurement · Figure 2c

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
MCP-dosed MIL-100(Al) EPR g-valueMarked as a best value within this paper	2.0044	—	—	Text Exact Reported	3269 · Radical Generation on MIL-100(Al) · Figure 2c
MCP-dosed MIL-100(Al) EPR peak width	11.0 G	—	—	Text Exact Reported	3269 · Radical Generation on MIL-100(Al) · Figure 2c
MCP-dosed radical concentration after solvent extractionMarked as a best value within this paper	1.0 x 10^18 spins/g	—	—	Text Rounded Reported	3269 · Radical Generation on MIL-100(Al) · Figure 3a
MCP-dosed radical concentration before solvent extraction	1.9 x 10^18 spins/g	—	—	Text Rounded Reported	3269 · Radical Generation on MIL-100(Al) · Figure 3a

Electron paramagnetic resonance (EPR)

Electron paramagnetic resonance

MIL-100(Fe) powder · Powder

MIL-100(Fe) and MIL-100(Cr) before and after MCP/CT dosing and 250 C treatment.

Context: Fe/Cr pristine and guest-loaded comparison
Measurement source: 3271 · Radical Generation in MIL-100(Cr) and MIL-100(Fe) · Figure 4b-c; Figures S25-S26

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Aromatic radicals on dosed MIL-100(Cr)Marked as a best value within this paper	EPR radical signals virtually nonmeasurable	—	—	Text Qualitative	3271 · Radical Generation in MIL-100(Cr) and MIL-100(Fe) · Figure 4c; Figure S26
Pristine MIL-100(Fe) broad EPR g-value	2.014	—	—	Text Exact Reported	3271 · Radical Generation in MIL-100(Cr) and MIL-100(Fe) · Figure 4b
Pristine MIL-100(Fe) broad EPR peak width	1070 G	—	—	Text Exact Reported	3271 · Radical Generation in MIL-100(Cr) and MIL-100(Fe) · Figure 4b
Aromatic radicals on dosed MIL-100(Fe)Marked as a best value within this paper	No aromatic radical species generated	—	—	Text Qualitative	3271 · Radical Generation in MIL-100(Cr) and MIL-100(Fe) · Figure 4b; Figure S25

Infrared spectroscopy of adsorbed CD3CN probe molecule

Infrared spectroscopy

MIL-100(Al) powder · Powder

CD3CN adsorption on MIL-100(Al), MIL-100(Cr), and MIL-100(Fe) to compare Lewis acidity.

Context: pristine framework family
Measurement source: 3267 · Other Measurements · Figure S31

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
MIL-100(Al) coordinated CD3CN broad band rangeMarked as a best value within this paper	2424-2364 cm-1	—	—	Text Range	3271 · Radical Generation in MIL-100(Cr) and MIL-100(Fe) · Figure S31
MIL-100(Cr) coordinated CD3CN nu(CN)	2359 cm-1	—	—	Text Exact Reported	3272 · Radical Generation in MIL-100(Cr) and MIL-100(Fe) · Figure S31
MIL-100(Fe) coordinated CD3CN nu(CN)	2351 cm-1	—	—	Text Exact Reported	3272 · Radical Generation in MIL-100(Cr) and MIL-100(Fe) · Figure S31

57Fe Mossbauer spectroscopy

Mossbauer spectroscopy

MIL-100(Fe) powder · Powder

As-synthesised MIL-100(Fe); Wissel iso-accelerated spectrometer with 57Co/Rh source.

Context: pristine Fe framework
Measurement source: 3267 · Other Measurements · Figure S24

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
MIL-100(Fe) Mossbauer isomer shifts	0.40(2), 0.38(3), 0.64(5) mm/s	—	parenthetical uncertainties reported	Text Exact Reported	3271 · Radical Generation in MIL-100(Cr) and MIL-100(Fe) · Figure S24
MIL-100(Fe) Mossbauer quadrupole splittings	0.70(2), 0.27(3), and 0.64(5) mm/s	—	parenthetical uncertainties reported	Text Exact Reported	3271 · Radical Generation in MIL-100(Cr) and MIL-100(Fe) · Figure S24

Solid-state 27Al MAS NMR

Nuclear magnetic resonance

MIL-100(Al) powder · Powder

Bruker Ascend 700 MHz, resonance frequency 182.44 MHz; precursor-dosed samples activated under vacuum at 150 C for 12 h before NMR.

Context: pristine and guest-loaded Al framework
Measurement source: 3267 · Solid-State Nuclear Magnetic Resonance (NMR) Measurement · Figure 3c; Figures S10, S17

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
MCP-dosed MIL-100(Al) shifted 27Al NMR peak	2.3 ppm	—	—	Text Exact Reported	3270 · Radical Generation on MIL-100(Al) · Figure 3c
Dehydrated MIL-100(Al) pentacoordinated Al signal	about 32.0 ppm	—	approximate	Text Approximate	3268 · Radical Generation on MIL-100(Al) · Figure S10
Parent MIL-100(Al) 27Al NMR six-coordinated Al peak	3.5 ppm	—	—	Text Exact Reported	3270 · Radical Generation on MIL-100(Al) · Figure 3c

X-ray photoelectron spectroscopy (XPS), Al 2p

X-ray photoelectron spectroscopy

MIL-100(Al) powder · Powder

PHI 5000 VersaProbe III with monochromatic Al Kalpha source; C 1s corrected to 284.8 eV.

Context: pristine and MCP/CT-dosed Al framework
Measurement source: 3267 · Other Measurements · Figure 3b; Figure S16

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Pristine MIL-100(Al) Al 2p binding energy	74.7 eV	—	—	Text Exact Reported	3270 · Radical Generation on MIL-100(Al) · Figure 3b

X-ray photoelectron spectroscopy (XPS), Fe 2p and Cr 2p

X-ray photoelectron spectroscopy

MIL-100(Fe) powder · Powder

MIL-100(Fe) and MIL-100(Cr) before and after precursor dosing.

Context: Fe/Cr pristine and guest-loaded comparison
Measurement source: 3271 · Radical Generation in MIL-100(Cr) and MIL-100(Fe) · Figure 4d-e; Figures S27-S28

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Parent MIL-100(Cr) Cr 2p1/2 binding energy	577.2 eV	—	—	Text Exact Reported	3271 · Radical Generation in MIL-100(Cr) and MIL-100(Fe) · Figure 4e
Parent MIL-100(Cr) Cr 2p3/2 binding energy	586.8 eV	—	—	Text Exact Reported	3271 · Radical Generation in MIL-100(Cr) and MIL-100(Fe) · Figure 4e
Parent MIL-100(Fe) Fe 2p1/2 binding energy	725.2 eV	—	—	Text Exact Reported	3271 · Radical Generation in MIL-100(Cr) and MIL-100(Fe) · Figure 4d
Parent MIL-100(Fe) Fe 2p3/2 binding energy	711.4 eV	—	—	Text Exact Reported	3271 · Radical Generation in MIL-100(Cr) and MIL-100(Fe) · Figure 4d