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Search for "Stokes shift" in Full Text gives 60 result(s) in Beilstein Journal of Organic Chemistry.

Rapid pseudo five-component synthesis of intensively blue luminescent 2,5-di(hetero)arylfurans via a Sonogashira–Glaser cyclization sequence

  • Fabian Klukas,
  • Alexander Grunwald,
  • Franziska Menschel and
  • Thomas J. J. Müller

Beilstein J. Org. Chem. 2014, 10, 672–679, doi:10.3762/bjoc.10.60

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  • quantum yield Φf. The same holds true for the comparison of the constitutional isomers 2i and 2j. Therefore, the twisted structure of 2j causes a larger Stokes shift and a much lower fluorescence quantum yield Φf. The huge Stokes shift originates from a considerable planarization in the excited state [42
  • quantum yield Φf. This finding correlates well with the planar ground state structure and an associated low Stokes shift. All studied representatives are potentially interesting singlet bluelight emitters. In addition, the electronic properties of the furans 2 have been studied by cyclic voltammetry
  • (22000). Fluorescence (CH2Cl2): λmax: 358 nm. Stokes shift Δ = 3800 cm−1. Quantum yield: Φf = 83% (Ref.: p-terphenyl (Φf = 93% in cyclohexane)). Cyclic voltammetry (CH2Cl2): E1/20/+1 = 1.25 V. Compounds 2d (solid and THF solution) and 2n (solid and THF solution) (from left to right) under daylight (top
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Published 18 Mar 2014

Synthesis, characterization and luminescence studies of gold(I)–NHC amide complexes

  • Adrián Gómez-Suárez,
  • David J. Nelson,
  • David G. Thompson,
  • David B. Cordes,
  • Duncan Graham,
  • Alexandra M. Z. Slawin and
  • Steven P. Nolan

Beilstein J. Org. Chem. 2013, 9, 2216–2223, doi:10.3762/bjoc.9.260

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  • emission can be easily tuned to achieve a variety of colors, i.e. from violet (3, λmax = 409 nm) to green (4, λmax = 516 nm). In each case, there is a considerable Stokes shift (27 to 166 nm). In terms of the intensity of emission, a wide range of values were recorded, although complexes could be
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Published 28 Oct 2013

Raman spectroscopy as a tool for monitoring mesoscale continuous-flow organic synthesis: Equipment interface and assessment in four medicinally-relevant reactions

  • Trevor A. Hamlin and
  • Nicholas E. Leadbeater

Beilstein J. Org. Chem. 2013, 9, 1843–1852, doi:10.3762/bjoc.9.215

Graphical Abstract
  • intensity at 1608 cm−1 is plotted against concentration, after subtraction of signals due to the solvent, the result is a straight line (Figure 5). The Stokes shift (which is being monitored) is inversely proportional to the temperature. Since the flow cell is situated after the product mixture exits the
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Published 11 Sep 2013

A new synthetic protocol for coumarin amino acid

  • Xinyi Xu,
  • Xiaosong Hu and
  • Jiangyun Wang

Beilstein J. Org. Chem. 2013, 9, 254–259, doi:10.3762/bjoc.9.30

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  • applications related to it [2][3][4][5][6][7][8]. Compound 1a is of great interest to scientists because the 7-hydroxycoumarin moiety has a high fluorescence quantum yield and a large Stokes shift. Its excellent fluorescence properties make it a great candidate to substitute green fluorescent protein (GFP) in
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Published 06 Feb 2013

Fluorescent hexaaryl- and hexa-heteroaryl[3]radialenes: Synthesis, structures, and properties

  • Antonio Avellaneda,
  • Courtney A. Hollis,
  • Xin He and
  • Christopher J. Sumby

Beilstein J. Org. Chem. 2012, 8, 71–80, doi:10.3762/bjoc.8.7

Graphical Abstract
  • anions [17]. The fluorescence of hexaaryl[3]radialenes has not been widely studied [42]. Solutions of compound 1 visibly fluoresce bright blue; its fluorescence maximum being 467 nm in dichloromethane with a Stokes shift of 124 nm (Table 2). The absorption and fluorescence properties of compound 3 had to
  • ]radialene being located predominantly on the exocyclic double bonds [40]. As a consequence, the electronic structure of the excited state is considerably more polar than that of the ground state.[42] This is consistent with the Stokes shift being 10–20 nm larger for the spectra measured in acetone and with
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Published 11 Jan 2012

Recent advances in direct C–H arylation: Methodology, selectivity and mechanism in oxazole series

  • Cécile Verrier,
  • Pierrik Lassalas,
  • Laure Théveau,
  • Guy Quéguiner,
  • François Trécourt,
  • Francis Marsais and
  • Christophe Hoarau

Beilstein J. Org. Chem. 2011, 7, 1584–1601, doi:10.3762/bjoc.7.187

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  • were identified with a two- and three-fold Stokes shift as compared to their DPO (diphenyloxazole) and POPOP (phenyloxazolephenyloxazolephenyl) references, and with high quantum yields (Scheme 11) [53]. Daugulis used the bulky butyldi-1-adamantylphosphine associated with the potassium phosphate base to
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Published 29 Nov 2011

Donor-acceptor substituted phenylethynyltriphenylenes – excited state intramolecular charge transfer, solvatochromic absorption and fluorescence emission

  • Ritesh Nandy and
  • Sethuraman Sankararaman

Beilstein J. Org. Chem. 2010, 6, 992–1001, doi:10.3762/bjoc.6.112

Graphical Abstract
  • substituents (–COMe and –COPh), the largest Stokes shift (140 nm, 8163 cm−1) was observed in ethanol. Linear correlation was observed for the Stokes shifts in a Lippert–Mataga plot. Linear correlation of Stokes shift was also observed with ET(30) scale for protic and aprotic solvents but with different slopes
  • substituent ) were unaffected by a change of solvent polarity, whereas in derivatives 1c–g the substituent had a strong effect on the emission maxima with increasing solvent polarity. In cases of 1c and 1f–g, the maximum Stokes shift was observed in DMSO where as in case of 1d–e the maximum Stokes shift was
  • induced Stokes shift. Correlation using ET(30) scale often follows two distinct lines, one for the non-protic solvents and other for the protic solvents. The data points corresponding to ethanol and isopropyl alcohol are indicated in Figure 6. In protic solvents specific solvent–fluorophore interaction
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Published 18 Oct 2010

Conjugated polymers containing diketopyrrolopyrrole units in the main chain

  • Bernd Tieke,
  • A. Raman Rabindranath,
  • Kai Zhang and
  • Yu Zhu

Beilstein J. Org. Chem. 2010, 6, 830–845, doi:10.3762/bjoc.6.92

Graphical Abstract
  • a strong fluorescence with maxima at 520 nm and a large Stokes-shift of 50 nm. However, due to the aliphatic structure of the main chain, the thermal stability was rather poor. Photoluminescent polyelectrolyte-surfactant complexes were obtained from an amphiphilic, unsymmetrically substituted DPP
  • monomer as well as conventional Pd-catalyzed coupling of M-1 and the 3,6-diphenyl(4,4´-bis(pinacolato)boron ester) derivative of DPP. The polymer exhibits a bordeaux-red colour in solution with absorption maxima of about 525 nm, and a purple luminescence with a maximum around 630 nm with a Stokes-shift of
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Published 31 Aug 2010

Chromo- and fluorophoric water-soluble polymers and silica particles by nucleophilic substitution reaction of poly(vinyl amine)

  • Katja Hofmann,
  • Ingolf Kahle,
  • Frank Simon and
  • Stefan Spange

Beilstein J. Org. Chem. 2010, 6, No. 79, doi:10.3762/bjoc.6.79

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  • range of Δ(1-M) = 524 cm−1 and Δ(1-P) = 760 cm−1, respectively. Furthermore, for 1-M only a small Stokes shift (9–15 nm) is observed, whereas 1-P shows a larger one (26–63 nm), which reaches a maximum in strong HBD solvents (HFIP). Again, the solvent-dependent fluorescence emission maxima can be
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Published 22 Jul 2010

Synthesis of the fluorescent amino acid rac-(7-hydroxycoumarin-4-yl)ethylglycine

  • Manfred Braun and
  • Torsten Dittrich

Beilstein J. Org. Chem. 2010, 6, No. 69, doi:10.3762/bjoc.6.69

Graphical Abstract
  • ), which not only displays a relatively large Stokes shift but also a fluorescence that is sensitive to both pH and solvent polarity [10][11]. Although a straightforward, short approach to the L-amino acid 1 has been reported [10], its isolation and purification was found to be difficult and tedious
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Published 24 Jun 2010
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