Sexithiophenes as efficient luminescence quenchers of quantum dots

• Christopher R. Mason,
• Yang Li,
• Paul O’Brien,
• Neil J. Findlay and
• Peter J. Skabara

Beilstein J. Org. Chem. 2011, 7, 1722–1731, doi:10.3762/bjoc.7.202

• dot emission was studied by photoluminescence spectroscopy and compared with the performance of alkyl end-capped sexithiophenes 2a and 2b. Keywords: electrochemistry; luminescence quenching; quantum dots; sexithiophenes; synthesis; Introduction Structurally well-defined oligothiophenes as functional

• , with retention of the photoluminescence behaviour of the quantum dot [24]. Herein, we present a comparative study on the photophysical properties of sexithiophenes 1 or 2 in varying concentrations, in the presence of a fixed concentration of CdSe(ZnS) core/shell quantum dots. Our choice of compounds

• incorporate a hexadecylamine (HDA) capping group and were prepared so as to ensure that their fluorescence did not overlap with the absorption profile of the sexithiophenes under study. Thus, the photoluminescence maximum for these quantum dots under excitation of light at 590 nm is 634 nm in chloroform

Novel carbazole–pyridine copolymers by an economical method: synthesis, spectroscopic and thermochemical studies

• Aamer Saeed,
• Madiha Irfan and
• Shahid Ameen Samra

Beilstein J. Org. Chem. 2011, 7, 638–647, doi:10.3762/bjoc.7.75

• . The weight average molecular masses (Mw) of the polymers were estimated by the laser light scattering (LLS) technique. Keywords: carbazole–pyridine copolymers; fluorescent materials; organic light emitting diode (OLED); photoluminescence spectra; UV spectra; Introduction An immense research effort

• is due to the optical transition attributed to the presence of the auxochromic OH group, which increases the conjugation length [31] and becomes part of extended chromophore. This effect is absent in the other compounds. The photoluminescence spectra of the polymer solutions of series P1 and P2 in

• . DSC graph for polymer P1a. UV–vis spectra of the polymers of (a) series P1 and (b) series P2. Photoluminescence spectra of polymers P1and P2 in CHCl3 solution. (a) Polymers of P2 series in visible light; (b) observed fluorescence (CHCl3 dilute solutions) under UV irradiation (254 nm). Synthesis of the

Pyridinium based amphiphilic hydrogelators as potential antibacterial agents

• Sayanti Brahmachari,
• Sisir Debnath,
• Sounak Dutta and
• Prasanta Kumar Das

Beilstein J. Org. Chem. 2010, 6, 859–868, doi:10.3762/bjoc.6.101

• microscopy (FESEM), atomic force microscopy (AFM), photoluminescence, FTIR studies, X-ray diffraction (XRD) and 2D NOESY experiments were carried out to elucidate the different non-covalent interactions responsible for the self-assembled gelation. The formation of three-dimensional supramolecular aggregates

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

• ; photoluminescence; solar cell; Introduction A useful strategy in the design of new polymers for electronic applications is to incorporate chromophores which are highly absorbing and emitting in the visible and near infrared region into π-conjugated polymers chains. Potentially useful chromophores for electronic