Spectroscopy — A Nanotubular Metal–Organic Framework with a Narrow Bandgap from Extended Conjugation**

3 measurement groups · 12 results

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

UV-vis absorption spectroscopy

UV-visible and optical absorption spectroscopy

Cu-H8TPPA red solid · Powder

Absorption spectra recorded with Shimadzu 2001 UV spectrophotometer using 1 cm path length cuvette at room temperature.

Geometry: 1 cm cuvette
Context: molecular precursor/control
Measurement source: 3 · Synthesis of Copper 5,10,15,20-Tetrakis [p-phenylphosphonic acid] porphyrin · Figure S4

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Colour change on Cu incorporation	green to red	—	—	Text Qualitative	3 · Synthesis of Copper 5,10,15,20-Tetrakis [p-phenylphosphonic acid] porphyrin
Cu-H8TPPA Q band	545 nm	—	—	Text Exact Reported	3 · Synthesis of Copper 5,10,15,20-Tetrakis [p-phenylphosphonic acid] porphyrin · Figure S4
Cu-H8TPPA Q band	582 nm	—	—	Text Exact Reported	3 · Synthesis of Copper 5,10,15,20-Tetrakis [p-phenylphosphonic acid] porphyrin · Figure S4
Cu-H8TPPA Soret/B band	418 nm	—	—	Text Exact Reported	3 · Synthesis of Copper 5,10,15,20-Tetrakis [p-phenylphosphonic acid] porphyrin · Figure S4

Solid-state diffuse reflectance spectroscopy (DRS) and Tauc analysis

UV-visible and optical absorption spectroscopy

GTUB-4 dark red needle-like crystals · Single Crystal

Crystalline-state optical band gap estimated from DRS collected using a Shimadzu 2600 UV-Vis-NIR spectrometer; direct and indirect Tauc plots considered.

Context: pristine GTUB-4 crystals
Measurement source: 6-7 · Band gap measurement · Figures S5-S7

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Direct optical bandgap	2.16 eV	—	—	Text Rounded Reported	1 · Abstract · Figure S6
Direct-transition Tauc fit quality	direct allowed transition Tauc factor does not provide a satisfactory fit	—	—	Text Qualitative	6 · Band gap measurement · Figure S6
Indirect optical bandgapMarked as a best value within this paper	1.9 eV	—	—	Text Rounded Reported	3 · Bandgap discussion · Figure 3; Figure S7

UV-vis absorption spectroscopy

UV-visible and optical absorption spectroscopy

H8-TPPA free-base porphyrin derivative · Powder

Absorption spectra recorded with Shimadzu 2001 UV spectrophotometer using 1 cm path length cuvette at room temperature.

Geometry: 1 cm cuvette
Context: molecular precursor/control
Measurement source: 2-3 · Synthesis of Copper 5,10,15,20-Tetrakis [p-phenylphosphonic acid] porphyrin · Figure S4

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
H8-TPPA Qy(1,0) band	518 nm	—	—	Text Exact Reported	3 · Synthesis of Copper 5,10,15,20-Tetrakis [p-phenylphosphonic acid] porphyrin · Figure S4
H8-TPPA Qy(0,0) band	553 nm	—	—	Text Exact Reported	3 · Synthesis of Copper 5,10,15,20-Tetrakis [p-phenylphosphonic acid] porphyrin · Figure S4
H8-TPPA Qx(1,0) band	593 nm	—	—	Text Exact Reported	3 · Synthesis of Copper 5,10,15,20-Tetrakis [p-phenylphosphonic acid] porphyrin · Figure S4
H8-TPPA Qx(0,0) band	650 nm	—	—	Text Exact Reported	3 · Synthesis of Copper 5,10,15,20-Tetrakis [p-phenylphosphonic acid] porphyrin · Figure S4
H8-TPPA Soret/B band	420 nm	—	—	Text Exact Reported	3 · Synthesis of Copper 5,10,15,20-Tetrakis [p-phenylphosphonic acid] porphyrin · Figure S4