Columnar/herringbone dual crystal packing of pyrenylsumanene and its photophysical properties

• Binod Babu Shrestha,
• Shuhei Higashibayashi and
• Hidehiro Sakurai

Beilstein J. Org. Chem. 2014, 10, 841–847, doi:10.3762/bjoc.10.80

• incorporating both bowl and planar structures. Pyrene was selected as the planar substituent when studying solid-state photophysical properties [21][22] and herein we report the columnar/herringbone dual crystal packing of pyrenylsumanene (1) in addition to its photophysical properties. Results and Discussion

First synthesis of meso-substituted pyrrolo[1,2-a]quinoxalinoporphyrins

• Dileep Kumar Singh and
• Mahendra Nath

Beilstein J. Org. Chem. 2014, 10, 808–813, doi:10.3762/bjoc.10.76

• been synthesized and their photophysical properties have not been evaluated yet. By considering the biological and fluorescent properties of these two classes of heterocycles, we envisaged to combine both porphyrin and pyrrolo[1,2-a]quinoxaline units in a single molecular framework to generate novel

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

• African trypanosomiasis [18][19][20], and against human renal cancer cells [21][22][23]. Furthermore, 2,5-di(hetero)arylfurans have been reported as photonic chromophores [24]. However, the electronic and photophysical properties of 2,5-di(hetero)aryl furans have only been occasionally studied [25][26][27

• in a one-pot fashion, which opens a ready access to biologically active furan derivatives. In addition the investigation of the photophysical properties of these compounds reveals an intense blue luminescence in solution approaching unity for the fluorescence quantum yield Φf of distinct derivatives

One-pot three-component synthesis and photophysical characteristics of novel triene merocyanines

• Christian Muschelknautz,
• Robin Visse,
• Jan Nordmann and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2014, 10, 599–612, doi:10.3762/bjoc.10.51

• -methyl (16a) and an N-tosyl intermediate (16b) clearly shows charge density differences at five distinct atoms (Table 3). All merocyanines 8 and 10 are expectedly deeply colored both in the solid state and in solution. For further investigation of the photophysical properties the absorption spectra were

The Flögel-three-component reaction with dicarboxylic acids – an approach to bis(β-alkoxy-β-ketoenamides) for the synthesis of complex pyridine and pyrimidine derivatives

• Mrinal K. Bera,
• Moisés Domínguez,
• Paul Hommes and
• Hans-Ulrich Reissig

Beilstein J. Org. Chem. 2014, 10, 394–404, doi:10.3762/bjoc.10.37

• light (253 nm) compound 22 shows fluorescence with a maximum intensity at 378 nm (see Supporting Information File 1 for details). The photophysical properties of structurally related pyridine–thiophene conjugates were recently investigated in detail [55][57][58]. Next, we investigated the

Flow synthesis of a versatile fructosamine mimic and quenching studies of a fructose transport probe

• Matthew B. Plutschack,
• D. Tyler McQuade,
• Giulio Valenti and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2013, 9, 2022–2027, doi:10.3762/bjoc.9.238

• NBDM, enabling us to measure key photophysical properties that will facilitate future uptake studies. Keywords: flow chemistry; fructose mimic; gluts; NBDM; Introduction The impact of dietary fructose on human health is not well-understood. A growing body of work suggests that those eating diets high

• of material. More NBDM is required to examine uptake across many cell lines and with access to amine 3, we can prepare analogues with different fluorophores or other types of tags. Finally, access to more NBDM will enable assessment of probe photophysical properties as a function of concentration and

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

• . Photophysical properties The spectroscopic properties of 1,8-naphthalimides are strongly dependent on the substituent at C-4 of the naphthalene ring. In general, the derivatives with a halogen atom or alkoxy groups are colorless and exhibit blue fluorecence [15][16], while the amino-substituted 1,8

• detection between 470 and 700 nm in toluene and ethanol. We observed a strong influence of the solvent on the photophysical properties of compound 4. In toluene, at 500 nm (corresponding to the fluorescence maximum), the fluorescence decay followed a mono-exponential law with a lifetime equal to 6.98 ns

Incorporation of perfluorohexyl-functionalised thiophenes into oligofluorene-truxenes: synthesis and physical properties

• Neil Thomson,
• Alexander L. Kanibolotsky,
• Joseph Cameron,
• Tell Tuttle,
• Neil J. Findlay and
• Peter J. Skabara

Beilstein J. Org. Chem. 2013, 9, 1243–1251, doi:10.3762/bjoc.9.141

• photophysical properties of the resulting oligomer. There are also less common examples of functionalisation at the C3, C8 and C13 positions [9]. Alkyl substituents attached to hetero- and carbocyles, which make up the conjugated backbone of oligomers and polymers, can also affect the properties of the material

Synthesis of phenanthridines via palladium-catalyzed picolinamide-directed sequential C–H functionalization

• Ryan Pearson,
• Shuyu Zhang,
• Gang He,
• Nicola Edwards and
• Gong Chen

Beilstein J. Org. Chem. 2013, 9, 891–899, doi:10.3762/bjoc.9.102

• the catalysis of Pd(OAc)2 affords phenanthridines in moderate to good yields. Applications of this method to the synthesis of more complex phenanthridines with novel photophysical properties are currently underway. Experimental General conditions: All commercial materials were used as received unless

Synthesis, photophysical and electrochemical characterization of terpyridine-functionalized dendritic oligothiophenes and their Ru(II) complexes

• Amaresh Mishra,
• Elena Mena-Osteritz and
• Peter Bäuerle

Beilstein J. Org. Chem. 2013, 9, 866–876, doi:10.3762/bjoc.9.100

• their photophysical properties is of great relevance, given the importance of oligothiophene and tpy-units as electro- and photoactive conjugated materials [21][28][29][30][31][32]. Besides these linear counterparts, various tpy-containing polymeric and dendritic structures have been developed and their

• photophysical properties studied [33][34][35][36][37][38]. However, to our knowledge, tpy-functionalized dendritic oligothiophenes have not been synthesized so far. The complexation of these dendrons could lead to interesting nanosized materials containing different chromophores to study electronic energy

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

Amino-substituted diazocines as pincer-type photochromic switches

• Hanno Sell,
• Christian Näther and
• Rainer Herges

Beilstein J. Org. Chem. 2013, 9, 1–7, doi:10.3762/bjoc.9.1

• ]diazocine (1), has been known for more than a hundred years [5]. However, only recently we discovered that the photophysical properties of 1 (quantum yields, photostationary states) are superior to those of parent azobenzene, and most of its derivatives [6][7][8]. In contrast to azobenzene, diazocine 1 is

• Discussion Synthesis Woolley et al. very recently published the synthesis of a 4,4’-diamino-2,2’-ethylene-bridged azobenzene (4,4’-diamino-EBAB), which exhibits excellent photophysical properties [9]. In planning our synthesis (and not yet being aware of the results of the above authors) we were concerned

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

• wide emission band during operation [8]. Taking into account the relevant photophysical properties of these organic compounds, new synthetic approaches were developed. Copolymerization of fluorene with thiophene, bithiophene or other aromatic comonomers is an alternative method for tuning the optical

• photophysical properties of PFs by using persilylated γ-CD as a new host molecule [33]. Inclusion of bithiophene into persilylated β-cyclodextrin, randomly methylated β-cyclodextrin, or chemically modified CD derivatives, followed by copolymerization with fluorene monomers results in significant changes in the

• illustrated in Scheme 1. In order to analyse the influence of end-capping reagents on the photophysical properties we changed the termination of the growing chains to 3T instead of bromobenzene, as in previously reported results [12]. A noncomplexed PDOF-BT copolymer was also synthesized by polycondensation

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

• with a variety of photophysical properties (mainly fluorescence) in DNA. It is important to mention here that guanine does not influence the photochromic properties of the diarylethene switch 4 as a DNA modification. In fact, the photoswitching behavior of 4 is maintained in all four different DNA

Molecular switches and cages

• Dirk Trauner

Beilstein J. Org. Chem. 2012, 8, 870–871, doi:10.3762/bjoc.8.97

• photoswitches continue to emerge and “old friends”, such as azobenzenes are constantly improved and optimized. This is not only true with respect to their photophysical properties but also with regard to their synthetic accessibility. Indeed, as molecular switches are applied in ever-increasing quantities, the

Syntheses and applications of furanyl-functionalised 2,2’:6’,2’’-terpyridines

• Jérôme Husson and
• Michael Knorr

Beilstein J. Org. Chem. 2012, 8, 379–389, doi:10.3762/bjoc.8.41

• photophysical properties, making them interesting in materials science [9][10][11][12]. Finally, the rich chemistry associated with five-membered heterocycles easily allows various chemical modifications. In this respect, the attachment of such heterocycles, directly or through a linker, to a tpy system appears

• electrochemical and photophysical properties of such compounds is therefore of crucial importance. In this context, the octahedral Ru(II) complex 43 was studied and compared with analogous pyrrolyl, thienyl and bithienyl-substituted compounds 66–68 (Figure 4) in order to obtain information about the influence of

• the pendant heterocycle on the physicochemical properties [56]. It appeared from this study that the bithienyl substituent has the most pronounced effect on the photophysical properties of this series of Ru complexes. Especially, 68 absorbs at a longer wavelength (Table 4), which constitutes an

Self-assembly of Ru₄ and Ru₈ assemblies by coordination using organometallic Ru(II)₂ precursors: Synthesis, characterization and properties

• Sankarasekaran Shanmugaraju,
• Dipak Samanta and
• Partha Sarathi Mukherjee

Beilstein J. Org. Chem. 2012, 8, 313–322, doi:10.3762/bjoc.8.34

• having complementary binding sites. Large numbers of molecular polygons and polyhedra have been synthesized mostly from cis-blocked Pd(II)- and Pt(II)-based building units due to their rigid square-planar coordination geometry as well as to their interesting photophysical properties [3][4][5]. However

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

• deficient hexaaryl[3]radialene observed thus far, and studies of their electrochemical and photophysical properties. Results and Discussion The first new [3]radialene compound targeted was hexa(pyrazol-1-yl)[3]radialene. However, the required starting material, 1-[(1H-pyrazol-1-yl)methyl]-1H-pyrazole

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

• be very efficient pH-triggered NLO switches. The fluorescent and photophysical properties of chromophores 88–93 were further studied [110][111]. The fluorescence was studied in various solvents and polymer matrices and at various temperatures. Intense fluorescence with quantum yields of 0.05 to 0.98

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

• , 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

• charged species. This increase is a consequence of the resonance effect of the phenyldimethylamine group. Sexithiophene/quantum dot composites in solution A comparative study on the photophysical properties of sexithiophenes 1a,b and 2a,b, in varying concentrations, with a fixed concentration of CdSe(ZnS

Synthesis and characterization of new diiodocoumarin derivatives with promising antimicrobial activities

• Hany M. Mohamed,
• Ashraf H. F. Abd EL-Wahab,
• Ahmed M. EL-Agrody,
• Ahmed H. Bedair,
• Fathy A. Eid,
• Mostafa M. Khafagy and
• Kamal A. Abd-EL-Rehem

Beilstein J. Org. Chem. 2011, 7, 1688–1696, doi:10.3762/bjoc.7.199

• ]. Moreover, coumarin-based dyes and pigments are organic fluorescent materials exhibiting unique photochemical and photophysical properties, which render them useful in a variety of applications such as dye lasers, anion sensors, organic light-emitting diodes and solar cells [9][10]. Iodo-organic derivatives

Synthesis of dye/fluorescent functionalized dendrons based on cyclotriphosphazene

• Aurélien Hameau,
• Sabine Fuchs,
• Régis Laurent,
• Jean-Pierre Majoral and
• Anne-Marie Caminade

Beilstein J. Org. Chem. 2011, 7, 1577–1583, doi:10.3762/bjoc.7.186

• publications have reported the synthesis, the study of photophysical properties and several uses of fluorescent dendrimers, emphasizing in particular their role as light-harvesters [4] for organic light-emitting diodes (OLEDs) [5] and as tools in biology [6]. Many different types of fluorophores have been

Fine-tuning alkyne cycloadditions: Insights into photochemistry responsible for the double-strand DNA cleavage via structural perturbations in diaryl alkyne conjugates

• Wang-Yong Yang,
• Samantha A. Marrone,
• Nalisha Minors,
• Diego A. R. Zorio and
• Igor V. Alabugin

Beilstein J. Org. Chem. 2011, 7, 813–823, doi:10.3762/bjoc.7.93

• states in these three isomers, whilst Stern–Volmer quenching experiments were used to investigate the kinetics of PET in these three systems. In the final part of this paper, we examine whether the observed trends in photochemical and photophysical properties correlate with DNA-cleaving activities of the

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

• polymer is 154 °C. All the polymers show glass transition temperatures above 150 °C (Table 1). Photophysical properties of the polymers The photophysical properties of the polymer, including absorption and emission spectral studies, were determined from solutions in chloroform. A summary of the measured

• * transition, and the shoulders correspond to n→π* transitions in the respective materials. A comparison of the photophysical properties of the synthesized polymers may be made with structurally related polymers previously synthesized by Zheng et al. [21][28]. The observed differences in the absorption spectra

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

• Oligo(p-phenyleneethynylene)s (oligoPPEs) have been frequently used as structural units for nanoscopic molecules because of their geometry and their electronic and photophysical properties [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19]. For their preparation three widely used