Photophysical analysis of dual fluorescence and phosphorescence emissions observed for semi-aliphatic polyimides at lower temperatures

Nara, Mayuko; Fujiwara, Eisuke; Vyšniauskas, Aurimas; Gulbinas, Vidmantas; Ando, Shinji

doi:10.1039/d4cp00538d

Cited by 1 publication

(1 citation statement)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…We have already reported that both BP-PI and DBrBP-PI are colorless and optically transparent amorphous films. 17,50 The pressure-dependent UV−vis absorption spectra of BP-PI and DBrBP-PI, shown in Figure 7, reveal that the absorption spectra of both PIs red-shifted as the pressure increased. This behavior, consistent with that observed for BP-MC and DBrBP-MC, is attributed to the biphenyl moiety becoming more planar, which extends the π-conjugation length.…”

Section: High-pressure Absorption/emission Spectra Of Polyimidesmentioning

confidence: 99%

Pressure-Induced Enhancement of Room-Temperature Phosphorescence in Heavy Halogen-Containing Imide and Polyimide

Liu,

Isoda,

Doi

et al. 2024

J. Phys. Chem. B

Self Cite

View full text Add to dashboard Cite

To investigate the correlation between the aggregated state and photoluminescence (PL) mechanism of dual fluorescent (FL) and phosphorescent (PH) polyimides (PIs), the photophysical processes of FL-type BP-PI, PH-type DBrBP-PI, and their corresponding imide model compounds (BP-MC and DBrBP-MC) dispersed in poly(methyl methacrylate) (PMMA) films were analyzed at elevated pressures up to 8 GPa using a diamond anvil cell. Dibromo-substituted DBrBP-MC demonstrated a shorter wavelength absorption than BP-MC owing to the larger dihedral angle in the biphenyl moiety. Both MCs exhibited red-shifts in their absorption spectra with increasing pressure, indicating planarization occurred at the biphenyl moieties associated with the compression of the free volume in PMMA. The PL intensity of BP-MC increased with increasing pressure, while its quantum yield (Φ PL ) decreased sharply due to the enhanced energy transfer via the Forster mechanism. In contrast, the PH quantum yield (Φ PH ) of DBrBP-MC monotonically increased at lower pressures, while it showed excitation wavelength-dependent behaviors at higher pressures: Φ PH remained unchanged under excitation at 340 nm but gradually increased under excitation at 365 nm. This fact suggests that, at higher pressures, 365 nm excitation promoted intersystem crossing (ISC) from excited singlet states at higher energy levels. Using this phenomenon, a significant pressure-induced PH enhancement (PIPE) was observed for DBrBP-PI up to 0.9 GPa upon excitation at 365 nm, which is a rare phenomenon for organic polymers. This study indicates that even in colorless and optically transparent amorphous polymers, an enhancement of PH due to restricted molecular motion and intensified ISC outweighs the deactivation due to intermolecular energy transfer under certain pressures, leading to an increase in Φ PH .

show abstract

Section: High-pressure Absorption/emission Spectra Of Polyimidesmentioning

confidence: 99%

Pressure-Induced Enhancement of Room-Temperature Phosphorescence in Heavy Halogen-Containing Imide and Polyimide

Liu,

Isoda,

Doi

et al. 2024

J. Phys. Chem. B

Self Cite

View full text Add to dashboard Cite

show abstract

Photophysical analysis of dual fluorescence and phosphorescence emissions observed for semi-aliphatic polyimides at lower temperatures

Abstract: The photoluminescence (PL) properties of four types of blue fluorescent semi-aliphatic polyimides (PIs) derived from aromatic dianhydrides (ODPA, BPDA, HQDEA, and BPADA) and an alicyclic diamine (DCHM) were investigated at...

Cited by 1 publication

References 37 publications

Pressure-Induced Enhancement of Room-Temperature Phosphorescence in Heavy Halogen-Containing Imide and Polyimide

Pressure-Induced Enhancement of Room-Temperature Phosphorescence in Heavy Halogen-Containing Imide and Polyimide

Contact Info

Product

Resources

About