The development of room temperature phosphorescence into a new technique for chemical determinations

Parker, R.T.; Freedlander, Richard S.; Dunlap, R. Bruce

doi:10.1016/s0003-2670(01)84343-9

Cited by 80 publications

(39 citation statements)

References 46 publications

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“…8,9 Another approach to obtain RT phosphorescent materials is the suppression of non-radiative T 1 decay by doping a host material, e.g. a filtering paper, with a compound capable of generating T 1 [10][11][12] or attaching a chromophore at the end of a polymer. 13 The resulting structure rigidification suppresses the collisional deactivation of T 1 , which is responsible for the nonradiative relaxation.…”

Section: Introductionmentioning

confidence: 99%

Visible room-temperature phosphorescence of pure organic crystals via a radical-ion-pair mechanism

Kuno

Akeno

Ohtani

et al. 2015

Phys. Chem. Chem. Phys.

120

106

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The afterglow of phosphorescent compounds can be distinguished from background fluorescence and scattered light by a time-resolved observation, which is a beneficial property for bioimaging. Phosphorescence emission accompanies spin-forbidden transitions from an excited singlet state through an excited triplet state to a ground singlet state. Since these intersystem crossings are facilitated usually by the heavy-atom effect, metal-free organic solids are seldom phosphorescent, although these solids have recently been refurbished as low-cost, eco-friendly phosphorescent materials. Here, we show that crystalline isophthalic acid exhibits room-temperature phosphorescence with an afterglow that lasts several seconds through a nuclear spin magnetism-assisted spin exchange of a radical ion pair. The obvious afterglow that facilitates a time-resolved detection and the unusual phosphorescence mechanism that enables emission intensification by nuclear spin managements are promising for exploiting the phosphorescence materials in novel applications such as bioimaging.

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Section: Introductionmentioning

confidence: 99%

Visible room-temperature phosphorescence of pure organic crystals via a radical-ion-pair mechanism

Kuno

Akeno

Ohtani

et al. 2015

Phys. Chem. Chem. Phys.

120

106

View full text Add to dashboard Cite

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“…Surprisingly, however, there has been a proliferation of reports on the room temperature phosphorescence (RTP) of heavyatom-free, crystalline organic compounds in the past few years. 46 Although the phosphorescence from organic compounds cooled at subzero temperatures 7 or RTP of those sup-ported on host materials 8 has been known for more than 40 years, RTP from single crystals has been scarcely reported. The fact that RTP is observable mostly in solid state can lead to a supposition that RTP is made possible by the attenuation of competing non-radiative transitions by restriction of molecular motions.…”

Section: Introductionmentioning

confidence: 99%

Intersystem Crossing Mechanisms in the Room Temperature Phosphorescence of Crystalline Organic Compounds

Yuasa

Kuno

2017

Bulletin of the Chemical Society of Japan

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Reports on the room temperature phosphorescence of metalfree organic crystals have been surging in the past few years. Together with interests in the rare phenomenon, these compounds have attracted attention for such potential applications as bio-imaging probes, oxygen sensors, and organic lightemitting diodes. For common organic compounds, phosphorescence is the emission from a triplet excited state, which is usually produced from a singlet excited state through intersystem crossing, a forbidden spin-flip of an electron. The mechanism of the forbidden process is the key to understanding such rare phenomenon and designing new phosphorescence materials. In this account, we make commentaries on the main intersystem crossing mechanisms proposed to date of the room temperature phosphorescence of heavy-atom-free, crystalline organic compounds, focusing on our own findings.

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“…Room-temperature phosphorescence (RTP) allows various compounds to be measured, including substances of biological and pharmaceutical interest, pesticides, and polycyclic aromatic hydrocarbons (1)(2)(3)(4). One of the methodologies employed is based on measuring the phosphorescence intensity emitted by the phosphor while fixed on an inert solid support such as filter paper (5)(6)(7)(8), but this technique has the disadvantages of cumbersome sample preparation, critical drying requirements, and high phosphorescent background intensity from the filter paper substrate.…”

Section: Introductionmentioning

confidence: 99%

Determination of the Pesticide Napropamide in Soil, Pepper, and Tomato by Micelle-Stabilized Room-Temperature Phosphorescence

Pulgarı́n

Bermejo

2002

J. Agric. Food Chem.

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A selective and sensitive method for determining napropamide by room-temperature phosphorescence in SDS micelles is proposed and applied to the determination of this substance in a technical formulation and in spiked soil, pepper, and tomato samples. The use of phosphorescence enhancers such as sodium dodecyl sulfate (micellar agent), thallium (I) nitrate (external heavy atom), and sodium sulfite (deoxygenation agent) was studied and optimized to obtain maximum sensitivity. The determination was performed in 66 mM SDS, 30 mM thallium (I) nitrate, and 8 mM sodium sulfite. Taking into account both maximum phosphorescence intensity and the time required to reach that, a pH value of 7.2 was selected. After the samples were left standing at room temperature for 10 min, the phosphorescence was totally developed. The intensity was then measured at lambda(ex) = 282 nm and lambda(em) = 528 nm. The calibration graph was linear for 50-600 ng mL(-1) napropamide. The detection limit, according to the error propagation theory, was 16 ng mL(-1). The method has been demonstrated for the analysis of soils, peppers, and tomatoes, but, because of matrix interference, the method of standard additions was applied to determine napropamide in the vegetable samples. Recoveries from all these matrixes of added napropamide were near 100%.

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The development of room temperature phosphorescence into a new technique for chemical determinations

Cited by 80 publications

References 46 publications

Visible room-temperature phosphorescence of pure organic crystals via a radical-ion-pair mechanism

Visible room-temperature phosphorescence of pure organic crystals via a radical-ion-pair mechanism

Intersystem Crossing Mechanisms in the Room Temperature Phosphorescence of Crystalline Organic Compounds

Determination of the Pesticide Napropamide in Soil, Pepper, and Tomato by Micelle-Stabilized Room-Temperature Phosphorescence

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