Absorption and emission spectra and triplet decay of some aromatic and N-heterocyclic compounds in polymethylmethacrylate

West, Michael; McCallum, K. J.; Woods, R. J.; Formosinho, Sebastião J.

doi:10.1039/tf9706602135

Cited by 27 publications

(6 citation statements)

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“…Interestingly, very long lifetimes can be recorded, making these samples very appealing as luminescent materials. These values are much larger than the previously reported triplet lifetime of phenanthrene in PMMA (0.77 s) [52] . Additionally, calculation of the corresponding radiative and non‐radiative rate constants, from the φ and τ values, demonstrated that, as expected, the non‐radiative relaxation is less favored in PMMA (Table 6).…”

Section: Resultsmentioning

confidence: 45%

Effect of Gold(I) on the Room‐Temperature Phosphorescence of Ethynylphenanthrene

Aquino

Caparrós

Aullón

et al. 2020

Chemistry A European J

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The synthesis of two series of gold(I) complexes with the general formulae PR3‐Au‐C≡C‐phenanthrene (PR3=PPh3 (1 a/2 a), PMe3 (1 b/2 b), PNaph3 (1 c/2 c)) or (diphos)(Au‐C≡C‐phenanthrene)2 (diphos=1,1‐bis(diphenylphosphino)methane, dppm (1 d/2 d), 1,4‐bis(diphenylphosphino)butane, dppb (1 e/2 e)) has been realized. The two series differ in the position of the alkynyl substituent on the phenanthrene chromophore, being at the 9‐position (9‐ethynylphenanthrene) for the L1 series and at the 2‐position (2‐ethynylphenanthrene) for the L2 series. The compounds have been fully characterized by 1H, 31P NMR, and IR spectroscopy, mass spectrometry, and single‐crystal X‐ray diffraction resolution in the case of compounds 1 a, 1 e, 2 a, and 2 c. The emissive properties of the uncoordinated ligands and corresponding complexes have been studied in solution and within organic matrixes of different polarity (polymethylmethacrylate and Zeonex). Room‐temperature phosphorescence (RTP) is observed for all gold(I) complexes whereas only fluorescence can be detected for the pure organic chromophore. In particular, the L2 series presents better luminescent properties regarding the intensity of emission, quantum yields, and RTP effect. Additionally, although the inclusion of all the compounds in organic matrixes induces an enhancement of the observed RTP owing to the decrease in non‐radiative deactivation, only the L2 series completely suppresses the fluorescence, giving rise to pure phosphorescent materials.

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Section: Resultsmentioning

confidence: 45%

Effect of Gold(I) on the Room‐Temperature Phosphorescence of Ethynylphenanthrene

Aquino

Caparrós

Aullón

et al. 2020

Chemistry A European J

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“…The triplet states of acridine and phenazine were monitored at 440 nm. 15 All time-resolved signals used for analysis and shown in the figures were an average ob-©…”

Section: Methodsmentioning

confidence: 99%

Behavior of singlet molecular oxygen (1.DELTA.gO2) in a polymer matrix: effects of temperature, matrix rigidity, and molecular composition

Clough¹,

Dillon²,

Iu³

et al. 1989

Macromolecules

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Singlet molecular oxygen ( 'Ago2) has been created, by energy transfer, from a triplet-state photosensitizer in a variety of solid organic polymers. In independent time-resolved experiments, the phosphorescence of 'Ago2 and the absorbance of the sensitizer triplet state were monitored as a function of the sample temperature, matrix rigidity, and molecular composition. In more glassy samples, the time-dependent behavior of the ' Agoz phosphorescence signal is strikingly different from that observed in liquid analogues, exhibiting long decay times with non-first-order kinetics. As the polymer matrix is made leas glassy, however, either by an increase in temperature or by using copolymers or low molecular weight additives, the lAg02 phosphorescence signal appearance and disappearance rates increase, approaching rates observed in liquid solvent analogum. At this limit, the '$02 decay follows fmborder kinetics. The triplet sensitizer flash absorption data indicate that, in the glassy organic polymers, the time-dependent behavior of the 1$02 phosphorescence signal principally reflects that of its precursor. Deconvolution of the sensitizer decay from the experimentally observed (or manifest) 'Ago2 phosphorescence signal yields intrinsic 'Ago2 lifetimes which, to a first-order determination, are independent of temperature and matrix rigidity and are approximately equivalent in magnitude to those recorded in liquid-phase analogues. In this convolution integral, it is necessary to incorporate a model in which the 'Ago2 sensitizer exists in a distribution of nonequivalent sites in the polymer matrix.Data obtained from a perdeuterated polymer give an intrinsic 'Ago2. lifetime that is an order of magnitude longer compared with that obtained from a perprotiated analogue and indicate that a solid-phase matrix exerts control over the intrinsic rate of 'Ago2 deactivation in a way very similar to that in liquid-phase systems.

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“…Molecules for study are chosen from those listed in the table. The lifetimes determined by a number of workers (13)(14)(15) are summarized in the central column. Provided that the polymer solutions are prepared carefully according to literature procedures,2 there is no difficulty in obtaining decay rates which agree well with those in the table.…”

Section: Hydrocarbons In Polymethylmethacrylatementioning

confidence: 99%

Flash photolysis experiments for teaching kinetics and photochemistry

Goodall¹,

Harrison²,

Wedderburn³

1972

J. Chem. Educ.

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Absorption and emission spectra and triplet decay of some aromatic and N-heterocyclic compounds in polymethylmethacrylate

Cited by 27 publications

References 0 publications

Effect of Gold(I) on the Room‐Temperature Phosphorescence of Ethynylphenanthrene

Effect of Gold(I) on the Room‐Temperature Phosphorescence of Ethynylphenanthrene

Behavior of singlet molecular oxygen (1.DELTA.gO2) in a polymer matrix: effects of temperature, matrix rigidity, and molecular composition

Flash photolysis experiments for teaching kinetics and photochemistry

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