The photophysics, physical photochemistry, and related spectroscopy of thiocarbonyls

Maciejewski, Andrzej; Steer, Ronald P.

doi:10.1021/cr00017a005

Cited by 285 publications

(355 citation statements)

References 75 publications

Supporting

Mentioning

329

Contrasting

Order By: Relevance

“…This is consistent with the conclusions drawn from 1 H NMR studies that CB [7] formed a stronger complex than CB [8] with thioketones. The lifetimes of the triplets and oxygen quenching rate constants measured by time-resolved techniques are included in Table 1.…”

Section: 7supporting

confidence: 92%

See 2 more Smart Citations

Closed Nanocontainer Enables Thioketones to Phosphoresce at Room Temperature in Aqueous Solution

et al. 2010

View full text Add to dashboard Cite

Thiocarbonyl compounds possess unusual photophysical properties: they fluoresce from S 2 , phosphoresce from T 1 only at extremely low concentrations in solution at room temperature, have unit quantum yield of intersystem crossing from S 1 to T 1 , undergo self-quenching at diffusion-controlled rates, and are quenched by ground-state oxygen leading to self-destruction. In this article, we are concerned with finding a new method to observe phosphorescence from thioketones at room temperature in aqueous solution at high concentrations. To achieve this goal, one needs to find ways to eliminate diffusion-limited self-quenching and oxygen quenching. We present here a general strategy that has allowed us to record phopshorescence from a number of thioketones in aqueous solution at room temperature. The method involves encapsulation of thioketone molecules within a "closed nanocontainer" made up of two cavitand molecules known by its trivial name as octa acid. In these supramolecular complexes, despite two thiocarbonyl compounds being present in close proximity, no self-quenching occurs within the confined space due to curtailment of their rotational freedom. Although phosphorescence could also be observed when these thioketones are included in open containers, such as cucurbiturils and cyclodextrines, the closed container made up of octa acid is found to be the best medium to observe phosphorescence from thioketones whose excited state chemistry is essentially controlled by self-quenching.

show abstract

Section: 7supporting

confidence: 92%

“…For comparison, lifetimes at infinite dilution in perfluorodimethylcyclohexane taken from the literature are included. 7 It is important to note that at 10…”

Section: 7mentioning

confidence: 99%

See 1 more Smart Citation

Closed Nanocontainer Enables Thioketones to Phosphoresce at Room Temperature in Aqueous Solution

et al. 2010

View full text Add to dashboard Cite

show abstract

“…These bands are not seen in the toluene solution in Figure 4(c) or pure styrene. 2 Formation of a triplet biradical adduct by reaction of a triplet thione and an alkene has been suggested, 10,28,29 and the band positions are in agreement with the computed infrared frequencies for the triplet biradical addition product 3 [MBT-St] provided in Table 3. We could not observe the predicted band at 1253 cm -1 because of its small absorption intensity and spectral overlap with the MBT bleach band centred at 1249 cm -1 .…”

Section: Tvas Of Mbt In Styrene Solutionsupporting

confidence: 78%

“…[6][7][8][9] The photochemistry of thione compounds is well-studied, and it is widely accepted that the first triplet excited state (T1) plays a major role in their photochemical reactions. 10,11 The thione triplet excited state is thought to be efficiently formed though ultrafast intersystem crossing (ISC) from the first singlet excited state (S1), in contrast to slower ISC in the corresponding oxygen-atom containing compounds, because of the larger spin-orbit coupling derived from the sulfur atom. 12,13 The S1 state has optically "dark" nπ* character in the Franck-Condon region, but can be populated by internal conversion (IC) from the second excited singlet state (S2) which is optically bright and has 1 * character.…”

Section: Introductionmentioning

confidence: 99%

Triplet state formation and quenching dynamics of 2-mercaptobenzothiazole in solution

Koyama

Orr-Ewing

2016

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

show abstract

Photochemical reactions ofT1 benzopyranthione 3-methylpentane

Kozłowski

Maciejewski

Milewski

et al. 1999

J. Phys. Org. Chem.

View full text Add to dashboard Cite

Photochemical properties of the lowest triplet state of 4H-1-benzopyran-4-thione (BPT) in 3-methylpentane were studied in the thione concentration range 10 À7 À 10 À3 M. The quantum yield of the photochemical decomposition of BPT was found to be highly concentration dependent. For low BPT concentrations (`10 À6 M) a reaction with the solvent is responsible for the consumption of the thione. In the concentration range 1 Â 10 À6 -8 Â 10 À5 M the main process is the reaction of thiyl radicals, formed in the primary reaction of hydrogen abstraction from a solvent molecule, with BPT molecules in the ground state. For thione concentrations b10 À4 M, the BPT triplet decays almost entirely in a self-quenching process. HPLC analysis showed that five different photoproducts, including an oligomer, are formed. Knowledge of earlier studied photophysical properties of BPT in 3-methylpentane and perfluoroalkanes permitted a quantitative explanation of the mechanism of photochemical reactions of 3 (BPT). The studies indicate, for BPT concentrations`10 À4 M, a dominant role of the interaction of 3 (BPT) with the solvent and the subsequent caged radical recombination in deactivation of BPT in the T 1 state.

show abstract

The photophysics, physical photochemistry, and related spectroscopy of thiocarbonyls

Cited by 285 publications

References 75 publications

Closed Nanocontainer Enables Thioketones to Phosphoresce at Room Temperature in Aqueous Solution

Closed Nanocontainer Enables Thioketones to Phosphoresce at Room Temperature in Aqueous Solution

Triplet state formation and quenching dynamics of 2-mercaptobenzothiazole in solution

Photochemical reactions ofT1 benzopyranthione 3-methylpentane

Contact Info

Product

Resources

About