The effect of permodified cyclodextrins encapsulation on the photophysical properties of a polyfluorene with randomly distributed electron-donor and rotaxane electron-acceptor units

• Aurica Farcas,
• Ana-Maria Resmerita,
• Pierre-Henri Aubert,
• Flavian Farcas,
• Iuliana Stoica and
• Anton Airinei

Beilstein J. Org. Chem. 2014, 10, 2145–2156, doi:10.3762/bjoc.10.222

• used to synthesize copolymers with smaller electrochemical and optical band gaps, so that materials with improved electronic and optical properties can be obtained [17]. The construction of mechanically interlocked molecules such as rotaxanes and polyrotaxanes with native cyclodextrins (CDs) as

• polyrotaxanes. The roughness exponent α calculated as the slope of log(Sq) versus log(Lsc) for the reference 4, 4a and 4b polyrotaxanes. Molecular weight (Mn in g∙mol−1), polydispersity index (Mw/Mn), coverage ratio, and thermal properties of the copolymers. Optical properties of copolymers. The redox

Aryl substitution of pentacenes

• Andreas R. Waterloo,
• Anna-Chiara Sale,
• Dan Lehnherr,
• Frank Hampel and
• Rik R. Tykwinski

Beilstein J. Org. Chem. 2014, 10, 1692–1705, doi:10.3762/bjoc.10.178

• nucleophilic addition (yields given are for the pentacene product 3, over the two steps from either 4a or 4b). Functionalization of iodoaryl pentacene 3g using the Suzuki–Miyaura cross-coupling reaction. Optical properties of pentacenes 3a–k, unsubstituted pentacene (PEN), and TIPSPc. Thermal properties of a

Synthesis of new, highly luminescent bis(2,2’-bithiophen-5-yl) substituted 1,3,4-oxadiazole, 1,3,4-thiadiazole and 1,2,4-triazole

• Anastasia S. Kostyuchenko,
• Vyacheslav L.Yurpalov,
• Aleksandra Kurowska,
• Wojciech Domagala,
• Adam Pron and
• Alexander S. Fisyuk

Beilstein J. Org. Chem. 2014, 10, 1596–1602, doi:10.3762/bjoc.10.165

• their extended conjugation and frequently have to be rendered soluble by introducing long alkyl- or alkoxy-type side substituents. This functionalisation opens up an additional route to modifying their redox, electronic and optical properties by using side substituents with different electron accepting

• ]-1,3,4-oxadiazole [16]. Similarly, the position of the substitution with solubilising groups and the length of the side chains lead to a significant change of the quantum yield [11]. The effect of the central ring nature on the optical properties of 13–15 and 18 is clearly observed. In Figure 2

Synthesis and spectroscopic properties of 4-amino-1,8-naphthalimide derivatives involving the carboxylic group: a new molecular probe for ZnO nanoparticles with unusual fluorescence features

• Laura Bekere,
• David Gachet,
• Vladimir Lokshin,
• Wladimir Marine and
• Vladimir Khodorkovsky

Beilstein J. Org. Chem. 2013, 9, 1311–1318, doi:10.3762/bjoc.9.147

• addition of ZnO NPs (solid curve). Excitation wavelength: 325 nm. The inset shows the same normalized spectra. Synthesis and structures of 1,8-naphthalimides. Possible ionization and complexation of 4 in ethanol. Optical properties of derivatives 1–4, 6 in ethanol. Solvent-dependent optical properties of

Superstructures of fluorescent cyclodextrin via click-reaction

• Arkadius Maciollek,
• Helmut Ritter and
• Rainer Beckert

Beilstein J. Org. Chem. 2013, 9, 827–831, doi:10.3762/bjoc.9.94

• fluorescent nature [1][2]. These optical properties can be used for the development of sensor molecules, blue emitting dyes, luminescent materials or as donor–(π-conjugated-bridge)–acceptor-type dyes in dye-sensitized solar cells [3][4][5]. The etherification of 4-hydroxythiazole by using propargyl bromide

Spin state switching in iron coordination compounds

• Philipp Gütlich,
• Ana B. Gaspar and
• Yann Garcia

Beilstein J. Org. Chem. 2013, 9, 342–391, doi:10.3762/bjoc.9.39

• exhibit thermally induced spin transition, known as spin crossover, depending on the nature of the coordinating ligand sphere. Spin transition in such compounds also occurs under pressure and irradiation with light. The spin states involved have different magnetic and optical properties suitable for their

Synthesis and characterization of low-molecular-weight π-conjugated polymers covered by persilylated β-cyclodextrin

• Aurica Farcas,
• Ana-Maria Resmerita,
• Andreea Stefanache,
• Mihaela Balan and
• Valeria Harabagiu

Beilstein J. Org. Chem. 2012, 8, 1505–1514, doi:10.3762/bjoc.8.170

• polymeric architectures. Moreover, the fabrication of mechanically interlocked molecules, such as polyrotaxanes, has been investigated as a method for the further improvement of thermal and electro-optical properties through the insulating backbones of conjugated polymers [20][21][22][23][24]. The studies

• reduced interchain interactions, which allow the polyrotaxane chains to pack densely. A better quality of the film, with higher uniformity, flatness, and better mechanical properties, is always desirable for optoelectronic applications. The optical properties of the PDOF-BT and PDOF-BTc compounds (not

Recent advances towards azobenzene-based light-driven real-time information-transmitting materials

• Jaume García-Amorós and
• Dolores Velasco

Beilstein J. Org. Chem. 2012, 8, 1003–1017, doi:10.3762/bjoc.8.113

• information beyond the time scale of microseconds, as well as to produce molecular materials with high oscillation frequencies in their optical properties. In addition, the possible design of such materials in such a way that they would be soluble in water (an environmentally friendly solvent) could be a

Diarylethene-modified nucleotides for switching optical properties in DNA

• Sebastian Barrois and
• Hans-Achim Wagenknecht

Beilstein J. Org. Chem. 2012, 8, 905–914, doi:10.3762/bjoc.8.103

• switching of optical properties in DNA can be achieved selectively at 310 nm (forward) and 450 nm (backward); both wavelengths are outside the normal nucleic acid absorption range. Moreover, this nucleoside was proven to be photochemically stable and allows switching back and forth several times. These

• . Diarylethenes have been applied in a noncovalent chiroptical photoswitchable DNA complex [33] and combined with 7-deazaadenosine to obtain a nucleosidic diarylethene switch [34]. Recently, we reported, very preliminarily, the preparation and optical properties of nucleoside 4 [30]. Herein, we give a full

• intermediate 16 yielding phosphoramidite 17. By automated DNA synthesis on a solid phase we prepared a set of four oligonucleotides in order to report preliminarily the optical properties of 4 in DNA. The sequences were identical except for the base pairs that surround the position of nucleoside 4. The

Synthesis and characterization of a novel carboxyl group containing (co)polyimide with sulfur in the polymer backbone

• Miroslav Mrsevic,
• David Düsselberg and
• Claudia Staudt

Beilstein J. Org. Chem. 2012, 8, 776–786, doi:10.3762/bjoc.8.88

• area of separation processes or optical applications, due to their excellent mechanical-, thermal- and optical properties, their superior processability and the ability to adapt their properties to a wide range of special applications. Therefore, two series of novel (co)polyimides containing

• air leading to a change in optical properties, which often causes undesired optical aberrations [9]. It has been shown that cross-linking can significantly inhibit swelling phenomena in membranes prepared from DABA (3,5-diaminobenzoic acid) functionalized (co)polyimides [10][11][12]. This approach is

• -containing (co)polyimides. These (co)polyimides, which were synthesized from a combination of different monomers with special properties, show excellent solubilities, very low water sorptions, and very good optical properties, making them highly attractive for optical applications. Results and Discussion

Thiophene-based donor–acceptor co-oligomers by copper-catalyzed 1,3-dipolar cycloaddition

• Stefanie Potratz,
• Amaresh Mishra and
• Peter Bäuerle

Beilstein J. Org. Chem. 2012, 8, 683–692, doi:10.3762/bjoc.8.76

• -shifted in comparison to that of 12 (λmax = 337 nm) and 13 (λmax = 339 nm). This band is not ascribed to individual bithienyl subunits, but to a weak conjugation through the triazole ring, caused by the donor–acceptor–donor system. Maarseveen et al. recently published synthesis and optical properties of

• of 6 to 14% were determined which are rather high for bithiophenes (1.8%) [40] and increased with increasing molecular size and conjugation. Obviously, the 1,2,3-triazole ring stabilizes the excited state by decreasing the probability of non-radiative deactivation. Comparable to the optical

• properties, cyclic voltammetry of 5, 6, and 10–14 revealed redox transitions of the individual thiophene moieties (Table 3). Thus, cyclic voltammograms (CV) of 5 and 10 (5 × 10−3 M in dichloromethane/tetrabutylammonium hexafluorophosphate (TBAPF6, 0.1 M, 100 mV s−1) showed characteristic oxidation waves of

Liquid-crystalline heterodimesogens and ABA-heterotrimesogens comprising a bent 3,5-diphenyl-1,2,4-oxadiazole central unit

• Govindaswamy Shanker,
• Marko Prehm and
• Carsten Tschierske

Beilstein J. Org. Chem. 2012, 8, 472–485, doi:10.3762/bjoc.8.54

• anchoring determines the optical properties of the investigated samples. If the surface layer is nontilted (SmA-like) then the sample adopts a homeotropic alignment, which appears completely dark. Indeed for compounds CB-Ox/n with a NcybA–CybA transition the birefringent Schlieren texture disappears upon

Perhydroazulene-based liquid-crystalline materials with smectic phases

• Zakir Hussain,
• Henning Hopf and
• S. Holger Eichhorn

Beilstein J. Org. Chem. 2012, 8, 403–410, doi:10.3762/bjoc.8.44

• molecular design of new liquid crystals, electro-optical properties can now be predicted quite precisely based on molecular modeling [1][2]. However, full evaluation of the value of a new structure is still only possible after synthesis. In the past few years many attempts have been made to improve the

Imidazole as a parent π-conjugated backbone in charge-transfer chromophores

• Jiří Kulhánek and
• Filip Bureš

Beilstein J. Org. Chem. 2012, 8, 25–49, doi:10.3762/bjoc.8.4

• intramolecular charge transfer (ICT) are reviewed. Design, synthetic pathways, linear and nonlinear optical properties, electrochemistry, structure–property relationships, and the prospective application of such D-π-A organic materials are described. This review focuses on Y-shaped imidazoles, bi- and

• due to a more difficult synthesis. The purpose of this article is to review the recent progress in the design, development, and investigation of imidazole-derived charge-transfer chromophores. Synthetic pathways, linear and nonlinear optical properties, electrochemistry, and the prospective

• investigated in terms of their synthesis and basic (non)linear optical properties [42][43][44][45][46]. Wu et al. utilized 4,5-bis(4-aminophenyl)imidazole as a suitable donor moiety for the construction of the nitro C2-substituted imidazole push–pull systems with extended and varied π-conjugated pathway 15a–g

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

• separation potentials of 1b in the solid state compared to 2b. The HOMO–LUMO gap was determined from the difference in the onsets for the reduction and first-oxidation processes. Comparison of the optical properties of 1a, 1b, 2a and 2b in solution and solid state. The HOMO–LUMO gap was determined from the

Synthesis and self-assembly of 1-deoxyglucose derivatives as low molecular weight organogelators

• Guijun Wang,
• Hao Yang,
• Sherwin Cheuk and
• Sherman Coleman

Beilstein J. Org. Chem. 2011, 7, 234–242, doi:10.3762/bjoc.7.31

• gels into another stable conformation. The study indicated that the formation of diacetylene gel is an effective method to obtain polydiacetylenes with interesting optical properties. Conclusion We have synthesized a series of 1-deoxy glucose derived esters, and screened their gelation in several

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

• -position). While the optical properties were quite similar, the EL properties were inferior. This was ascribed to a reduced conjugation length in these polymers. Novel vinyl ether-functionalized polyfluorenes for active incorporation in common photoresist materials were described by Kühne et al. [35] Among

• versus voltage of polymer light-emitting diode containing P-5: ITO/P-5/OXD7/Ca/Mg:Al:Zn (from [28]). Optical properties of some diphenylDPP-based conjugated polymers. Optical properties of copolymers P-21 and P-22 based on two isomeric diphenylDPP monomer units (from [48]). Absorption

Polar tagging in the synthesis of monodisperse oligo(p-phenyleneethynylene)s and an update on the synthesis of oligoPPEs

• Dhananjaya Sahoo,
• Susanne Thiele,
• Miriam Schulte,
• Navid Ramezanian and
• Adelheid Godt

Beilstein J. Org. Chem. 2010, 6, No. 57, doi:10.3762/bjoc.6.57

• inserted remote from the polyconjugated backbone in order not to change the optical properties of the oligomers. Polar tagging with e.g. the rather inert ether moiety within the side chains at a site distant from the backbone appears to us a generally useful concept for the synthesis of mesoscopic

Synthetic incorporation of Nile Blue into DNA using 2′-deoxyriboside substitutes: Representative comparison of (R)- and (S)-aminopropanediol as an acyclic linker

• Daniel Lachmann,
• Sina Berndl,
• Otto S. Wolfbeis and
• Hans-Achim Wagenknecht

Beilstein J. Org. Chem. 2010, 6, No. 13, doi:10.3762/bjoc.6.13

• (Scheme 1). However, we have shown that the ethidium dye connected to D-threoninol as a linker bearing three carbon atoms between the phosphodiester bridges has nearly the same optical properties as the shorter (S)-3-amino-1,2-propanediol linker [38]. It is important to point out, however, that chirality

• explore how important the chirality of the 3-amino-1,2-propanediol linker is with respect to the optical properties of an attached fluorophore. We chose Nile Blue as the fluorescent probe for these experiments since the redox properties of this phenoxazinium label exhibit a potential sufficient for

• has no significant influence on the optical properties since the absorption spectra are remarkably similar. The latter result is similar to the S-configured linker [16]. All results together indicate once more that it does not matter if an S- or R-configured acyclic linker system is used to attach

Synthesis of indolo[3,2-b]carbazole-based new colorimetric receptor for anions: A unique color change for fluoride ions

• Ajit Kumar Mahapatra,
• Giridhari Hazra and
• Prithidipa Sahoo

Beilstein J. Org. Chem. 2010, 6, No. 12, doi:10.3762/bjoc.6.12

• ), and not hydrogen bonding to it, is responsible for the drastic color change [47], as a result of a change in the optical properties of chromogenic indolocarbazole skeleton. This is in agreement with the NMR titration data. Such deprotonation was related to the acidity of the H-bond donor site and the