New laser dyes with blue-green emission

Schimitschek, Erhard J.; Trias, John A.; Hammond, P. R.; Henry, Ronald A.; Atkins, Ronald L.

doi:10.1016/0030-4018(76)90005-5

Cited by 92 publications

(73 citation statements)

References 5 publications

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“…This may be the main reason why the k ET (T) values are much smaller than the k ET (S) values. The k ET (T) value of 3 (DPAC + -CMC À ) is predicted from the Marcus curve in Figure 13 to be 6 10 2 s…”

Section: Dependence Of Intramolecular Et On Driving Forcementioning

confidence: 99%

“…When photoirradiation of a MeCN solution of DPA-CM with PhI was carried out at 77 K, a typical triplet ESR signal with zero-field splitting was observed at g = 2.0029 and 4.08 ( Figure 9). The zero-field splitting parameter D was determined from the fine structure of the triplet signal to be 40 G. The distance r between two unpaired electrons for the triplet radical ion pair, generated by photoinduced electron transfer from the DPA moiety to the triplet excited state of the CM moiety in DPA-CM, was determined to be 8.9 by using Equation (1): [48] D=G ¼ 27 800=ðr 3 =Þ ð1Þ…”

Section: Entrymentioning

confidence: 99%

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Photoinduced Electron Transfer in Photorobust Coumarins Linked with Electron Donors Affording Long Lifetimes of Triplet Charge‐Separated States

et al. 2010

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Electron donor (D) substituted 3-ethoxycarbonylcoumarin (CM) derivatives [D-CM: D = 4-diphenylaminophenyl (DPA), 4-diethylaminophenyl (DEA), 4-dimethylaminophenyl (DMA), and 2-methyl-4-dimethylaminophenyl (MeDMA)] are synthesized and characterized. Photoinduced electron transfer (ET) from the D moiety to the acceptor (CM) and back electron transfer (BET) are investigated by femtosecond and nanosecond laser flash photolysis measurements. Femtosecond laser excitation at 355 nm of a deaerated acetonitrile (MeCN) solution of D-CM shows generation of the singlet charge-separated (CS) state [(1)(D(.+)-CM(.-))] by ET from D to the singlet excited state of the CM moiety ((1)CM*), and this is followed by rapid decay within 3 ns to afford the triplet excited state (D-(3)CM*). Nanosecond laser excitation of a deaerated MeCN solution of D-CM results in formation of the triplet CS state by ET from D to (3)CM*. The quantum yield of formation of the triplet CS state [(3)(DPA(.+)-CM(.-))] in the presence of iodobenzene (PhI) in deaerated MeCN increases with increasing concentration of PhI to reach 27 % at 0.5 M PhI. The triplet CS state decays by bimolecular BET because of the long CS lifetime by unimolecular BET. Formation of the long-lived triplet CS state was confirmed by electron spin resonance (ESR) measurements. The photorobust nature of DPA-CM is demonstrated by multiple laser pulse excitation (>1000 times) at 355 nm. The photoinduced ET and BET rate constants of a series of D-CM are thoroughly analyzed in light of the Marcus theory of electron transfer.

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Section: Dependence Of Intramolecular Et On Driving Forcementioning

confidence: 99%

Section: Entrymentioning

confidence: 99%

Photoinduced Electron Transfer in Photorobust Coumarins Linked with Electron Donors Affording Long Lifetimes of Triplet Charge‐Separated States

et al. 2010

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“…7-Aminocoumarins are a well-known important group of chromophores that emit in the blue-green spectral region, with their fluorescence quantum yields often close to unity [36][37][38]. As the structures contain an electron-donating amino group at the 7-position and an electron-withdrawing carbonyl group, 7-aminocoumarins are polarized in the ground state.…”

Section: Excited-state Dynamics Of Coumarin 151mentioning

confidence: 99%

QM/MM Study of Excited‐State Solvation Dynamics of Biomolecules

Taketsugu

Kina

Nakayama

et al. 2010

Hydrogen Bonding and Transfer in the Excited State

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“…Natural and synthetic coumarins continue to engage interest for their wide ranging applications e.g., in the areas of biological activities [1][2][3][4], laser dyes [5][6][7][8][9][10], fluorescence brighteners [11][12][13][14] and fluorochromophores [15][16][17][18]. Among a class of 3-(heteroaryl) coumarins, a variety of 3-(thiazolyl) coumarins containing a biologically significant heterocycle, thiazole has been synthesized and evaluated as pharmaceutically active agents, fluorescence probes and laser dyes [19][20][21][22].…”

Section: Introductionmentioning

confidence: 99%

π‐Aryl/heteroaryl conjugated coumarin‐thiazoles: Synthesis, optical spectral and nonlinear optic properties

Mashraqui

Mistry

Sundaram

2006

Journal of Heterocyclic Chem

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A series of -aryl/heteroaryl conjugated coumarin-thiazole systems 8a-f has been synthesized by using Hantzsch thiazole protocol and Wittig olefination as the keys. In the UV-Visible spectra of 8a-f, a main absorption band associated with a dominant -* transition is observed in the region of 338 to 390 nm. Qualitatively, the values of max have been found to correlate satisfactory with the donor/acceptor characteristics of the -attached chromophores. Marked changes observed in the absorption maxima of 8a under acidic conditions are rationalized on the basis of mono-or bis-protonation and modification of the donor/acceptor properties of chromophores undergoing protonation. The emission spectra of 8a-f, obtained by exciting the molecules at their main absorption bands showed emission maxima in the region of 429 nm to 537 nm, with relatively high Stokes shifts of 145 and 171 nm being observed for 8a and 8e, carrying a -donor, dimethylaminophenyl and a -acceptor, p-nitrophenyl chromophore, respectively. Although, the first hyperpolarisability , measured by the hyper-Reileigh scattering (HRS) technique are modest (12 to 23 10 -30 esu), all the compounds exhibited complete transparency in the frequency doubling region at 532 nm and showed high thermal stability (T d from 330 to 365 °C).

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New laser dyes with blue-green emission

Cited by 92 publications

References 5 publications

Photoinduced Electron Transfer in Photorobust Coumarins Linked with Electron Donors Affording Long Lifetimes of Triplet Charge‐Separated States

Photoinduced Electron Transfer in Photorobust Coumarins Linked with Electron Donors Affording Long Lifetimes of Triplet Charge‐Separated States

QM/MM Study of Excited‐State Solvation Dynamics of Biomolecules

π‐Aryl/heteroaryl conjugated coumarin‐thiazoles: Synthesis, optical spectral and nonlinear optic properties

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