Photophysical study of a multi-chromophoric dendrimer by time-resolved fluorescence and femtosecond transient absorption spectroscopy

Hofkens, Johan; Latterini, Loredana; Belder, G. De; Gensch, Thomas; Maus, Michael; Vosch, Tom; Karni, Y.; Schweitzer, Gerd; Schryver, F. C. De; Hermann, Andreas; Müllen, Kläus

doi:10.1016/s0009-2614(99)00287-0

Cited by 81 publications

(108 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Note that the existence of excimerlike interactions was invoked to explain the fast excited-state dynamics of another type of dendrimer macromolecule bases on phenylene building blocks. 8,9 To test the possibility of intramolecular interactions such as energy transfer or excimerlike formation, we investigated several isolated cases with dendrimer structures containing synthetic fragments ͑components͒ of either carbazole or nitroaminostilbene ͑NAS͒ functional groups. In the last case we measured the fluorescence dynamics and steady-state spectra for model compounds containing either one ͑NS1, Fig.…”

Section: Methodsmentioning

confidence: 99%

“…However, there have been only a few reports concerning the investigations of photodynamics of dendrimer molecules, specifically photoexcitation dynamics on ultrafast ͑femtosecond͒ time scales. 8,9 In the present paper femtosecond time-resolved fluorescence experiments, which probe the relaxation processes in a nonlinear optical ͑NLO͒ dendrimer are reported. The present work is devoted to the very fast fluorescence dynamics of organic dendrimers for NLO and light-emitting diode applications.…”

Section: Introductionmentioning

confidence: 93%

See 1 more Smart Citation

Femtosecond luminescence dynamics in a nonlinear optical organic dendrimer

et al. 2000

View full text Add to dashboard Cite

The ultrafast intrinsic dynamics of an organic dendrimer in solution and in a thin film is reported using fluorescence upconversion spectroscopy. Femtosecond decay is detected at higher emission energies, while at lower energies a fluorescence rise time (ϳ3 ps͒ was observed that is dependent on the solvent's polarity. A strong excitation energy dependence of the decay pattern was also observed. Different synthetic functional groups that comprise the macromolecular dendrimer structure were investigated. The mechanism, which describes the complex dynamics in the dendrimer system, was found to be associated with the excitation of the attached chromophore nitroaminostilbene. These results indicate the absence of excited-state interactions of functional groups within the dendrimer macromolecule. A model, which includes the existence of an intermediate nonradiative state, is proposed to describe the complex ultrafast fluorescence dynamics in the dendrimer system.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 93%

Femtosecond luminescence dynamics in a nonlinear optical organic dendrimer

et al. 2000

View full text Add to dashboard Cite

show abstract

“…The pump probe geometry for fs-TA measurements was kept at magic angle (54.7 • ) to eliminate the contribution from rotational diffusion of solute molecules on the transient decay signal. [40][41][42][43] However, in the case of transient URLS measurements, experiments were performed in parallel configuration in order to obtain a better signal-tonoise ratio. The time resolution for both fs-TA and URLS is ∼200 fs.…”

Section: B Transient Absorption and Urls Setupmentioning

confidence: 99%

Mode specific excited state dynamics study of bis(phenylethynyl)benzene from ultrafast Raman loss spectroscopy

Roy

Kayal

Ariese

et al. 2017

The Journal of Chemical Physics

View full text Add to dashboard Cite

Femtosecond transient absorption (fs-TA) and Ultrafast Raman Loss Spectroscopy (URLS) have been applied to reveal the excited state dynamics of bis(phenylethynyl)benzene (BPEB), a model system for one-dimensional molecular wires that have numerous applications in opto-electronics. It is known from the literature that in the ground state BPEB has a low torsional barrier, resulting in a mixed population of rotamers in solution at room temperature. For the excited state this torsional barrier had been calculated to be much higher. Our femtosecond TA measurements show a multi-exponential behaviour, related to the complex structural dynamics in the excited electronic state. Time-resolved, excited state URLS studies in different solvents reveal mode-dependent kinetics and picosecond vibrational relaxation dynamics of high frequency vibrations. After excitation, a gradual increase in intensity is observed for all Raman bands, which reflects the structural reorganization of Franck-Condon excited, non-planar rotamers to a planar conformation. It is argued that this excited state planarization is also responsible for its high fluorescence quantum yield. The time dependent peak positions of high frequency vibrations provide additional information: a rapid, sub-picosecond decrease in peak frequency, followed by a slower increase, indicates the extent of conjugation during different phases of excited state relaxation. The CC triple (–C≡C–) bond responds somewhat faster to structural reorganization than the CC double (>C=C<) bonds. This study deepens our understanding of the excited state of BPEB and analogous linear pi-conjugated systems and may thus contribute to the advancement of polymeric “molecular wires.”

show abstract

“…Dendrimers containing photoactive units [7][8][9][10][11][12][13][14][15][16][17] are particularly interesting for two reasons: (1) cooperation among the photoactive components can allow the dendrimer to perform specific functions, and (2) changes in the properties of photoactive components can be exploited to monitor the participation of dendrimers in chemical processes.…”

Section: -6mentioning

confidence: 99%

Synthesis of Poly(3,4,5-trihydroxybenzoate amide) and Poly(3,4,5-trihydroxybenzoate ester) Dendrimers from Polyphenols and Their Chemiluminescence

Lee¹,

Song²,

Lee³

et al. 2012

Bulletin of the Korean Chemical Society

View full text Add to dashboard Cite

Dendrimer chemistry is rapidly expanding for fundamental reasons as well as due to requirements in technological applications.1 A recent interesting development in dendrimer chemistry concerns the coordination of metal ions by interior branches or exterior units. 2-6Dendrimers containing photoactive units 7-17 are particularly interesting for two reasons: (1) cooperation among the photoactive components can allow the dendrimer to perform specific functions, and (2) changes in the properties of photoactive components can be exploited to monitor the participation of dendrimers in chemical processes.Polyphenols such as pyrogallol and gallic acid (GA) produce a singlet oxygen in the presence of hydrogen peroxide in an alkaline medium and emit light. GA has also been utilized for selective Co 2+ detection using a chemiluminescence (CL) flow injection system. The CL intensities of polyphenols are considerably weaker than those of luminal and acridinium ester, which are representative CL compounds. Hence, trans-4-(3-propionic acid) phenylboronic acid and 4-biphenylboronic acid in the presence of peroxidase or 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide have been used as an enhancer for highly sensitive polyphenol CL determination. However, methods to derive polyphenols with strong CL intensity have not been reported yet. 18In recent times, after a new polymer, poly(amidoamine) dendrimer, was synthesized, dendrimers have been applied to material engineering based on optics in nanoscale science. The poly(propylene amine) family that was functionalized in the periphery with fluorescent dansyl units interacts with Co 2+. More recently, acridinium dendrimers have been conjugated with bovine serum albumin, and its CL was estimated to be six times that of the acridinium salt.In this paper, we report the design of new types of polyphenol dendrimers having an increased number of chemiluminophores for high CL intensity; they also have hydroxyl groups in their periphery to form hydrogen bonds with an analyte. Polyphenol dendrimers having GA in the periphery were synthesized, and their CL was measured. We synthesized first-generation polyphenol dendrimers with GA units in the periphery by employing a divergent method using phenol, pyrocatechol, resorcinol, hydroquinone, 1,2,4-trihydroxybenzene, 3,4,5-trihydroxybenzene aniline, 1,2-diaminobenzene, and 1,3-diaminobenzene as the core molecules (Supporting information, Schemes 1 and 2).Experimental methods and physical data from polyol 1a-f to first-generation esters 5a-f have been reported in our previous paper. 19The mass spectra of the zero-generation esters 3a-f and first-generation esters 5a-5f were obtained by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI TOF MS) using 2,5-dihydroxybenzoic acid as the matrix. The amide group has a rigid, planer structure as a consequence of resonance interactions that give the amide bond ~40% double bond character. The planer conformation maximizes π-bonding overlap, which accounts for the amide group's ri...

show abstract

Photophysical study of a multi-chromophoric dendrimer by time-resolved fluorescence and femtosecond transient absorption spectroscopy

Cited by 81 publications

References 19 publications

Femtosecond luminescence dynamics in a nonlinear optical organic dendrimer

Femtosecond luminescence dynamics in a nonlinear optical organic dendrimer

Mode specific excited state dynamics study of bis(phenylethynyl)benzene from ultrafast Raman loss spectroscopy

Synthesis of Poly(3,4,5-trihydroxybenzoate amide) and Poly(3,4,5-trihydroxybenzoate ester) Dendrimers from Polyphenols and Their Chemiluminescence

Contact Info

Product

Resources

About