Spectroscopy — Defects as Color Centers: The Apparent Color of Metal-Organic Frameworks Containing Cu2+-Based Paddle-Wheel Units

10 measurement groups · 19 results

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

variable angle spectroscopic ellipsometry (VASE), M2000 ellipsometer; Cauchy-layer optical box model

high-quality HKUST-1 HQ-SURMOF · Thin Film

HQ-SURMOF measured from 1.4-3.4 eV at incidence angles 55, 65 and 75 degrees; uncoated quartz substrate used as reference.

Geometry: thin film on quartz substrate
Context: low-defect pristine-framework thin film
Measurement source: S-5 · Supporting Information 4 · Figure S4

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
ellipsometry spectral range	1.4-3.4 eV	—	—	Caption Range	S-5 · Supporting Information 4 · Figure S4
HQ-SURMOF refractive index at 632.8 nmMarked as a best value within this paper	1.556 at 632.8 nm	—	—	Caption Exact Reported	S-5 · Supporting Information 4 · Figure S4
HQ-SURMOF film thicknessMarked as a best value within this paper	82 nm	—	—	Caption Exact Reported	S-5 · Supporting Information 4 · Figure S4

variable angle spectroscopic ellipsometry (VASE), M2000 ellipsometer; Cauchy-layer optical box model

conventional low-quality HKUST-1 SURMOF · Thin Film

Regular SURMOF measured from 1.4-3.4 eV at incidence angles 55, 65 and 75 degrees; uncoated quartz substrate used as reference.

Geometry: thin film on quartz substrate
Context: defect-rich pristine-framework thin film
Measurement source: S-5 · Supporting Information 4 · Figure S4

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
regular SURMOF refractive index at 632.8 nm	1.227 at 632.8 nm	—	—	Caption Exact Reported	S-5 · Supporting Information 4 · Figure S4
regular SURMOF film thickness	104 nm	—	—	Caption Exact Reported	S-5 · Supporting Information 4 · Figure S4

Raman spectroscopy

conventional low-quality HKUST-1 SURMOF · Thin Film

Raman spectra used to identify characteristic splitting of symmetric carboxylate stretch vibration associated with dinuclear paddle-wheel units.

Geometry: HKUST-1 SURMOF thin films
Context: HKUST-1 SURMOF thin films
Measurement source: 2 · Results and Discussions

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Raman carboxylate stretch splitting	characteristic splitting of symmetric carboxylate stretch vibration	—	—	Text Qualitative	2 · Results and Discussions

UV-vis absorption spectroscopy

UV-visible and optical absorption spectroscopy

1 mM copper(II) acetate in acetic acid · Unknown

1 mM copper(II) acetate in acetic acid; pure acetic acid solvent spectrum shown as dotted line.

Geometry: solution cuvette/path length not reported
Context: non-MOF Cu dimer reference
Measurement source: S-3 · Supporting Information 2 · Figure S2

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
copper(II) acetate Cu dimer molar extinction coefficient near 700 nm	192 L mol-1 cm-1 at approximately 700 nm	—	—	Caption Rounded Reported	S-3 · Supporting Information 2 · Figure S2

UV-vis absorption/transmission spectroscopy using a Cary5000 spectrometer; spectra normalised to 100 nm thickness

UV-visible and optical absorption spectroscopy

high-quality HKUST-1 HQ-SURMOF · Thin Film

High-quality HKUST-1 HQ-SURMOF compared with conventional SURMOF and quartz substrate over 200-1000 nm.

Geometry: thin film on quartz substrate
Context: low-defect pristine-framework thin film
Measurement source: 2 · Results and Discussions · Figure 2

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
normalised absorbance near 700 nm	approximately 0.06 a.u. at 700 nm from Figure 2 inset	—	—	Figure Axis Approximate	2 · Figure · Figure 2 inset
molar extinction coefficient at 700 nmMarked as a best value within this paper	approximately 1000 L mol-1 cm-1	—	—	Text Approximate	2 · Results and Discussions · Figure 2
residual absorption energy range	1.5-2.5 eV	—	—	Text Range	3 · Results and Discussions · Figure 4
visual colour of HQ-SURMOFMarked as a best value within this paper	almost transparent and only slightly turquoise	—	—	Caption Qualitative	2 · Figure caption · Figure 1b

UV-vis absorption/transmission spectroscopy using a Cary5000 spectrometer; spectra normalised to 100 nm thickness

UV-visible and optical absorption spectroscopy

conventional low-quality HKUST-1 SURMOF · Thin Film

Conventional low-quality HKUST-1 SURMOF compared with HQ-SURMOF and quartz substrate over 200-1000 nm.

Geometry: thin film on quartz substrate
Context: defect-rich pristine-framework thin film
Measurement source: 2 · Results and Discussions · Figure 2

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
normalised absorbance near 700 nm	approximately 0.13 a.u. at 700 nm from Figure 2 inset	—	—	Figure Axis Approximate	2 · Figure · Figure 2 inset
visual colour of conventional SURMOF	greenish-turquoise colour	—	—	Caption Qualitative	2 · Figure caption · Figure 1b

UV-vis absorption spectroscopy

UV-visible and optical absorption spectroscopy

pristine/HQ SURMOF after elevated-temperature exposure series · Thin Film

Pristine SURMOF compared with films exposed to 200 C for 16 h, 200 C for 72 h, 220 C for 24 h, and 250 C for 1 h, plotted from 300-900 nm in SI Figure S3a.

Atmosphere: elevated-temperature exposure before measurement; atmosphere not specified
Geometry: thin film on quartz substrate
Context: thermally defect-enriched SURMOF versus pristine SURMOF
Measurement source: S-4 · Supporting Information 3 · Figure S3a

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
elevated-temperature exposure effect on visible absorption	elevated-temperature treatments increase visible absorbance, especially 250 C for 1 h	—	—	Figure Axis Qualitative	S-4 · Supporting Information 3 · Figure S3a

UV-vis absorption spectroscopy

UV-visible and optical absorption spectroscopy

pristine/HQ SURMOF after 10 min water vapour exposure for UV-vis · Thin Film

Pristine SURMOF before and after water vapour exposure for 10 min, plotted from 300-900 nm in SI Figure S3b.

Atmosphere: water vapour exposure before measurement
Geometry: thin film on quartz substrate
Context: defect-enriched water-exposed SURMOF versus pristine SURMOF
Measurement source: S-4 · Supporting Information 3 · Figure S3b

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
water-vapour exposure effect on visible absorption	water-vapour-exposed SURMOF trace has higher visible absorbance than pristine trace	—	—	Figure Axis Qualitative	S-4 · Supporting Information 3 · Figure S3b

X-ray photoelectron spectroscopy (XPS)

X-ray photoelectron spectroscopy

high-quality HKUST-1 HQ-SURMOF · Thin Film

XPS in UHV apparatus under base pressure 10^-10 mbar; binding energies calibrated to carboxylate O 1s at 532.1 eV.

Atmosphere: ultrahigh vacuum, base pressure 10^-10 mbar
Geometry: thin film
Context: pristine HQ-SURMOF
Measurement source: 3 · Experimental Section · Figure 4

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Cu+ fraction in pristine HQ-SURMOFMarked as a best value within this paper	smaller than 3%	—	upper bound	Caption Approximate	3 · Figure caption · Figure 4
Cu(I) 2p3/2 binding energy	Cu(I) 930.8 eV	—	—	Figure Axis Rounded Reported	3 · Figure · Figure 4
Cu(II) 2p3/2 binding energy	Cu(II) 935.1 eV	—	—	Figure Axis Rounded Reported	3 · Figure · Figure 4

X-ray photoelectron spectroscopy (XPS)

X-ray photoelectron spectroscopy

HQ-SURMOF after water vapour exposure · Thin Film

XPS after 15 min water vapour exposure; same Cu 2p region comparison as pristine HQ-SURMOF.

Atmosphere: ultrahigh vacuum for XPS after water vapour exposure
Geometry: thin film
Context: defect-enriched water-exposed HQ-SURMOF
Measurement source: 3 · Figure caption · Figure 4

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Cu+ fraction after water vapour exposure	about 9%	—	—	Caption Approximate	3 · Figure caption · Figure 4