Spectroscopic studies of some laser dyes

Pavlopoulos, Theodore G.; Hammond, P. R.

doi:10.1021/ja00828a005

Cited by 107 publications

(41 citation statements)

References 14 publications

(26 reference statements)

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“…This second T-T band seriously overlaps with the fluorescence of TPP. If it were not for this second band appearing upon phenyl substitution, pyrene could be considered as a perfect case of the AZ1a constellation, according to Pavlopoulos and Hammond's notation for laser dyes (23). As a matter of fact, laser action was easily obtained with TPP in cyclohexane (21,24).…”

Section: Resultsmentioning

confidence: 99%

Phenyl Substitution Effects on Triplet–Triplet Absorption Spectra: I. Study of 1,3,6,8-Tetraphenylpyrene

Rullière¹,

Colson²,

Roberge³

1975

Can. J. Chem.

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The triplet–triplet (T–T) absorption spectrum of 1,3,6,8-tetraphenylpyrene (TPP) was measured from 400 to 620 nm. The data obtained are compared with theoretical calculations using the Ruedenberg–Scherr FEMO model. A planar triplet state is evidenced by fine vibrational structure. The T–T quenching rate constant measured (1.3 ± 0.1 × 109 M−1 s−1) is 20% of the expected diffusion-controlled value.

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Section: Resultsmentioning

confidence: 99%

Phenyl Substitution Effects on Triplet–Triplet Absorption Spectra: I. Study of 1,3,6,8-Tetraphenylpyrene

Rullière¹,

Colson²,

Roberge³

1975

Can. J. Chem.

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“…Efficient singlet-triplet intersystem crossing, population accumulation in the triplet state, and triplettriplet absorption in the dye fluorescence region hinder long-pulse and cw pumped dye laser action [33][34][35], while laser action by short pulse pumping remains possible. Eosin Y laser action in various solvents was reported in refs.…”

Section: Introductionmentioning

confidence: 99%

Triplet-triplet absorption of eosin Y in methanol determined by nanosecond excimer laser excitation and picosecond light continuum probing

Penzkofer

Beidoun

1993

Chemical Physics

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The absolute triplet-triplet absorption cross-section spectrum a T (X) of eosin Y in methanol at room temperature is determined in the wavelength region from 400 to 1000 nm and at 308 and 1054 nm. The triplet state is populated by XeCl excimer laser excitation to a singlet state and subsequent intersystem crossing. The triplet level population is determined by numerical simulation of the pump pulse absorption dynamics. The triplet-triplet absorption is probed with picosecond spectral light continua which are generated in a D 2 0 sample by a synchronized mode-locked Nd:glass laser. The decay of the triplet level population is studied by delayed picosecond light continua probing. Second order rate constants of hQ* =* i.l X10 9 dm 3 mol~l s~l for oxygen quenching, fc&> = i.3x 10 9 dm 3 mol~l s~l for triplet-triplet annihilation, and k$ ss4x 10 8 dm 3 mol~l s" 1 for triplet-singlet concentration quenching have been determined.

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“…Although the non-substituted p-quaterphenylene has been known for more than 125 years now [90] and like its higher oligomers is even commercially available, 1,4´´´-disubstituted derivatives and especially non-symmetrically functionalised compounds are still rare. This is mainly due to the notoriously low solubility of these compounds that almost prevents a (regio-)selective functionalisation [91,92]. In order to get access to substances with a defined substitution pattern it is therefore mandatory to introduce the desired functional groups into smaller building blocks and use these precursors to establish the synthesis of the p-quaterphenylene scaffold.…”

Section: Fig 12mentioning

confidence: 99%

“…1,4´´´-Dinitro-4,1´:4´,1´´:4´´,1´´´-quaterphenylene (NOP4) [92,112,202] Under an argon atmosphere 378 mg (1.00 mmol) of 4,4´-biphenyldiboronic acid bis-(neopentylglycol)ester, 548 mg (2.2 mmol, 2.2 equivalents) of 4-iodo-nitrobenzene, 608 mg (4.08 mmol, 4 equivalents) of cesium fluoride, and 58 mg (0.05 mmol, 5 mol%) of [Pd(PPh 3 ) 4 ] were dissolved in 50 mL of abs. THF and refluxed for 50 hours.…”

Section: Symmetrically Functionalised Para-quaterphenylenesmentioning

confidence: 99%

Organic Molecular Nanotechnology

Schiek

Balzer

Al‐Shamery

et al. 2008

Small

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Zur Homepage der Dissertation AbstractFormation of needle-like crystals from inorganic as well as from organic semiconductors such as para-phenylenes, α-thiophenes and phenyl-thiophene co-oligomers on dielectric surfaces has attracted increasing interest within the last years. The para-hexaphenylene has proven to be a versatile building block for generating long, parallely aligned organic nanofibers by a self-assembly process on a muscovite mica substrate via sublimation in high vacuum. These nanofibers possess outstanding optical properties like strong, polarised blue fluorescence in high quantum yields after unpolarised excitation with UV light, waveguiding and lasing features. Furthermore, they are chemically and thermically stable and can be easily detached from the growth substrate to serve as key elements in next generation optoelectronic and nanophotonic devices. Owing to their typical height and width on a nanometer scale and length up to one millimeter, the fibers bridge the gap between microscopic and macroscopic dimensions. The morphology of the nanofibers (length, height, width, aspect ratio, bending into rings) is susceptable to process parameters and pretreatment of the substrate. But chemically functionalisation of the molecular building block as key step of this thesis widens the scope of possibilities: Nanoaggregates with tailored morphology and optical properties are generated from designed functionalised molecular building blocks. Functional groups have been implemented at the 1,4´´´-para-positions of p-quaterphenylenes using a non-trivial Suzuki cross-coupling strategy. Symmetrically as well as non-symmetrically functionalised oligomers have been achieved in excellent yields and high purity. Additionally, the synthesis of phenyl-thiophene cooligomers and their acceptability for the nanofiber growth on muscovite mica via organic molecule deposition in high vacuum are presented. The fluorescence peak emission frequency of the nanostructures from the substituted p-quaterphenylenes shifts within the blue depending on the functionalisation. While dimensions are still influenced by the growth parameters, the overall shape (i.e. cross-section) of the aggregates alters significantly with the functional group. Even new properties like nonlinear optical activity are accessible. Due to intrinsic nonzero hyperpolarisability of push-pull functionalised oligomers, the respective nanofibers act as frequency doublers and emit strong second harmonic light after excitation with near infrared femtosecond laser pulses. Note that this design approach is possible while conserving the concept of highly crystalline nanofibers. Thus, a new route of bottom-up nanotechnology is presented starting from organic molecular synthesis towards generating of tailormade organic nanofibers opening new prospects for future nanotechnology. 3 ZusammenfassungDie Bildung von nadelförmigen Kristallen aus anorganischen und organischen Halbleitermolekülen wie zum Beispiel para-Phenylenen, α-Thiophenen und Phenylthiophen Co-oligomeren fa...

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Spectroscopic studies of some laser dyes

Cited by 107 publications

References 14 publications

Phenyl Substitution Effects on Triplet–Triplet Absorption Spectra: I. Study of 1,3,6,8-Tetraphenylpyrene

Phenyl Substitution Effects on Triplet–Triplet Absorption Spectra: I. Study of 1,3,6,8-Tetraphenylpyrene

Triplet-triplet absorption of eosin Y in methanol determined by nanosecond excimer laser excitation and picosecond light continuum probing

Organic Molecular Nanotechnology

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