Indenopyrans – synthesis and photoluminescence properties

• Andreea Petronela Diac,
• Ana-Maria Ţepeş,
• Albert Soran,
• Ion Grosu,
• Anamaria Terec,
• Jean Roncali and
• Elena Bogdan

Beilstein J. Org. Chem. 2016, 12, 825–834, doi:10.3762/bjoc.12.81

• ). However, a slight bathochromic shift could be observed when methylene chloride was used in contrast to a hypsochromic shift in the more polar solvent acetonitrile. The analysis of the absorption spectra revealed some differences between the regioisomers 2''b and 3''b and diastereoisomers 2' and 2'', as

• 310 nm (Figure 5, Table 3). Comparing the solution (acetonitrile) and solid-state fluorescence spectra of both diastereoisomers (Figure 5), one can observe a bathochromic shift of λmax in the solid state and a broadening of the emission band because of intermolecular interactions. Next, in order to

• bathochromic shift together with an emission-band broadening in contrast to their emission spectra recorded in solution. The supramolecular arrangement in the solid state of indenopyrone 6a is ensured by a number of non-covalent interactions such as intermolecular H-bonding, C–H···π and π···π contacts

Friedel–Crafts-type reaction of pyrene with diethyl 1-(isothiocyanato)alkylphosphonates. Efficient synthesis of highly fluorescent diethyl 1-(pyrene-1-carboxamido)alkylphosphonates and 1-(pyrene-1-carboxamido)methylphosphonic acid

• Anna Wrona-Piotrowicz,
• Janusz Zakrzewski,
• Anna Gajda,
• Tadeusz Gajda,
• Anna Makal,
• Arnaud Brosseau and
• Rémi Métivier

Beilstein J. Org. Chem. 2015, 11, 2451–2458, doi:10.3762/bjoc.11.266

• research. Compound 3a was also emissive in the solid state (λmax = 485 nm; ΦF = 0.25). The significant bathochromic shift (80 nm) and the broadness of the emission band in comparison with solution fluorescence (Figure 5) suggest the presence of emissive aggregates in the solid state. This was confirmed by

Star-shaped tetrathiafulvalene oligomers towards the construction of conducting supramolecular assembly

• Masahiko Iyoda and
• Masashi Hasegawa

Beilstein J. Org. Chem. 2015, 11, 1596–1613, doi:10.3762/bjoc.11.175

• absorption bands is clearly affected by the distance between two TTFs, and TTF dimer 19•+ linked with a longer spacer exhibited no intramolecular CT absorption band. Moreover, the longest absorption maxima of the dications 162+, 172+, and 182+ exhibit a bathochromic shift of 44, 30, and 14 nm, respectively

Synthesis and spectroscopic properties of β-triazoloporphyrin–xanthone dyads

• Dileep Kumar Singh and
• Mahendra Nath

Beilstein J. Org. Chem. 2015, 11, 1434–1440, doi:10.3762/bjoc.11.155

• demetalation under acidic conditions to afford the corresponding free-base porphyrins in good to excellent yields. After successful spectroscopic characterization, these porphyrins have been evaluated for their photophysical properties. The preliminary results revealed a bathochromic shift in the UV–vis and

• bathochromic shift in their electronic absorption and fluorescence spectra as compared to the meso-tetraarylporphyrins. These results are significantly encouraging and henceforth may be useful for the development of new porphyrin materials for various applications including photosensitizers for photodynamic

Tetrathiafulvalene-based azine ligands for anion and metal cation coordination

• Awatef Ayadi,
• Aziz El Alamy,
• Olivier Alévêque,
• Magali Allain,
• Nabil Zouari,
• Mohammed Bouachrine and
• Abdelkrim El-Ghayoury

Beilstein J. Org. Chem. 2015, 11, 1379–1391, doi:10.3762/bjoc.11.149

• pyridinecarboxaldehyde. In addition, E1ox of L2 is also anodically shifted when compared with E1ox of L1 because of the strong π-electron conjugation in ligand L2 and this is in agreement with the bathochromic shift observed for L2 in the UV–visible absorption spectra. Sensing properties of the azine ligands for anions

• ) presents the same features as the free ligand L2 with a red shift of the different absorption bands (Figure S10 in Supporting Information File 1). The ICT trasnsition suffers a bathochromic shift by about 100 nm as compared with the free ligand which indicates an increase of the electron acceptor effet of

Thiazole-induced rigidification in substituted dithieno-tetrathiafulvalene: the effect of planarisation on charge transport properties

• Rupert G. D. Taylor,
• Joseph Cameron,
• Iain A. Wright,
• Neil Thomson,
• Olena Avramchenko,
• Alexander L. Kanibolotsky,
• Anto R. Inigo,
• Tell Tuttle and
• Peter J. Skabara

Beilstein J. Org. Chem. 2015, 11, 1148–1154, doi:10.3762/bjoc.11.129

• –vis spectroscopy using dichloromethane (DCM) as the solvent (Figure 2). The obtained spectrum of compound 1 shows a maximum absorption at 380 nm and two less intense peaks at 308 nm and 274 nm. The most intensive absorption peak of 2 shows a 7 nm bathochromic shift compared to 1 and this main peak

Azobenzene-based inhibitors of human carbonic anhydrase II

• Leander Simon Runtsch,
• David Michael Barber,
• Peter Mayer,
• Michael Groll,
• Dirk Trauner and
• Johannes Broichhagen

Beilstein J. Org. Chem. 2015, 11, 1129–1135, doi:10.3762/bjoc.11.127

• Table 1. While the “naked” azobenzene 1h has the absorbance maximum in the bluest part of the spectrum (λmax (1h) = 322 nm), substitution on the azobenzene in the 4´-position leads to a bathochromic shift, which is smaller for electron-withdrawing groups (λmax (1g) = 328 nm; λmax (1i) = 342 nm) and more

• pronounced for electron-donating groups (λmax (1f) = 338 nm, λmax (1a) = 358 nm, λmax (1d) = 404 nm, λmax (1c) = 414 nm, and λmax (1b) = 460 nm). Interestingly, azide 1e with a Hammett constant of σ = 0.08 [12], exhibits a bathochromic shift (λmax (1e) = 356 nm) close to hydroxy azobenzene 1a although it can

• (as an indicator for electron-pushing or pulling effects). When plotted against each other a trend can be observed, which is reflected by a more bathochromic shift when the Hammett constant becomes more negative (Figure 4b). However, when plotting the Hammett constants or the maximal absorbance

A hybrid electron donor comprising cyclopentadithiophene and dithiafulvenyl for dye-sensitized solar cells

• Gleb Sorohhov,
• Chenyi Yi,
• Michael Grätzel,
• Silvio Decurtins and
• Shi-Xia Liu

Beilstein J. Org. Chem. 2015, 11, 1052–1059, doi:10.3762/bjoc.11.118

• affected by the presence of a phenyl spacer. For dye 1, without a phenyl ring, the D unit appears more difficult to oxidize due to a strong the electron-withdrawing effect of the A moiety, and also the lowest-energy absorption band shows a slight bathochromic shift compared to that for dye 2 with a phenyl

Chiroptical properties of 1,3-diphenylallene-anchored tetrathiafulvalene and its polymer synthesis

• Masashi Hasegawa,
• Junta Endo,
• Seiya Iwata,
• Toshiaki Shimasaki and
• Yasuhiro Mazaki

Beilstein J. Org. Chem. 2015, 11, 972–979, doi:10.3762/bjoc.11.109

• )tetrathiafulvalenylbenzene radical cation 10•+, which was reported previously [7] (Table 2). In the spectrum of 32+, the absorption maximum at 810 nm is assigned to an electronic transition to the SOMO in the TTF•+ moieties. The value was slightly red-shifted compared with that of 10•+ (775 nm). This small bathochromic

• shift can be ascribed to the conjugation to the central allene moiety. As for the spectrum of 34+, the absorption maximum at 667 nm, assigned to the HOMO–LUMO transition in the TTF2+ moieties, was also red-shifted compared with the corresponding absorption maximum (637 nm) of 102+. Similarly, cationic

Synthesis and chemosensing properties of cinnoline-containing poly(arylene ethynylene)s

• Natalia A. Danilkina,
• Petr S. Vlasov,
• Semen M. Vodianik,
• Andrey A. Kruchinin,
• Yuri G. Vlasov and
• Irina A. Balova

Beilstein J. Org. Chem. 2015, 11, 373–384, doi:10.3762/bjoc.11.43

• the PAE 10b with an additional acetylene fragment differed from the absorption spectrum of the PAE 10a by a small bathochromic shift (≈7 nm) of two absorption bands and an additional absorption band at 266 nm (Figure 6). The fluorescence emission spectra of the same solutions (Figure 7) were recorded

A comparative study of the interactions of cationic hetarenes with quadruplex-DNA forming oligonucleotide sequences of the insulin-linked polymorphic region (ILPR)

• Darinka Dzubiel,
• Heiko Ihmels,
• Mohamed M. A. Mahmoud and
• Laura Thomas

Beilstein J. Org. Chem. 2014, 10, 2963–2974, doi:10.3762/bjoc.10.314

• effect and a bathochromic shift of the absorption maximum of the ligand were observed upon addition of DNA (Supporting Information File 1, Figures S3 and S5). In the case of coralyne (2) and the tetraazoniahetarene derivative 5 this effect is only weakly pronounced. Only during the titration of the bis

Synthesis and properties of novel star-shaped oligofluorene conjugated systems with BODIPY cores

• Clara Orofino-Pena,
• Diego Cortizo-Lacalle,
• Joseph Cameron,
• Muhammad T. Sajjad,
• Pavlos P. Manousiadis,
• Neil J. Findlay,
• Alexander L. Kanibolotsky,
• Dimali Amarasinghe,
• Peter J. Skabara,
• Tell Tuttle,
• Graham A. Turnbull and
• Ifor D. W. Samuel

Beilstein J. Org. Chem. 2014, 10, 2704–2714, doi:10.3762/bjoc.10.285

• * transition of the oligofluorene arms [19]. As the number of fluorene units in the arm increases, this band becomes more intense and subjected to a bathochromic shift. The spectra of all compounds reveal the two features which are related to the presence of the BODIPY unit and can be assigned to S0–S1 and S0

• from HOMO to LUMO. The bathochromic shift of the peak of Y-B1 with respect to that of T-B1 is explained by the smaller twist of the fluorenes in the α-position in Y-B1 which results in some of the electron density in the LUMO being located on the fluorene units which is not the case for T-B1. Likewise

Solution processable diketopyrrolopyrrole (DPP) cored small molecules with BODIPY end groups as novel donors for organic solar cells

• Diego Cortizo-Lacalle,
• Calvyn T. Howells,
• Upendra K. Pandey,
• Joseph Cameron,
• Neil J. Findlay,
• Anto Regis Inigo,
• Tell Tuttle,
• Peter J. Skabara and
• Ifor D. W. Samuel

Beilstein J. Org. Chem. 2014, 10, 2683–2695, doi:10.3762/bjoc.10.283

• one-pot reaction. Extending the conjugated π-system of a compound leads to a narrower HOMO–LUMO gap and a bathochromic shift of the absorption spectrum. Both effects are usually desirable to enhance the solar absorption. Therefore, an extended analogue of compound 6 with an additional thiophene ring

A small azide-modified thiazole-based reporter molecule for fluorescence and mass spectrometric detection

• Stefanie Wolfram,
• Hendryk Würfel,
• Stefanie H. Habenicht,
• Christine Lembke,
• Phillipp Richter,
• Eckhard Birckner,
• Rainer Beckert and
• Georg Pohnert

Beilstein J. Org. Chem. 2014, 10, 2470–2479, doi:10.3762/bjoc.10.258

• )thiazol-4-ol (4). This derivative of the 4-hydroxythiazole family was already synthesized by Beckert et al. in a study focusing on the fluorescence properties of 4-hydroxythiazoles [29]. It exhibits an intense bathochromic shift of the UV–vis absorption when deprotonated at the 4-hydroxy position. The

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

• , entry 13), yet for the amorphous film the most pronounced bathochromic shift in the series of the merocyanines 10 (Figure 7). In the solid state a merocyanine characteristic metallic green luster can be seen. Again, the aryl substitution on the triene moiety only affects the absorption bands to a minor

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

• at 465 and 541 nm, respectively. As shown in Figure 1b the band maximum undergoes a marked bathochromic shift with increasing size and also compared to the parent dendrons 6 and 7, which further ascribed to the extended conjugation. The fluorescence quantum yields (Φf) of the ligands were found to be

Polymerization of novel methacrylated anthraquinone dyes

• Christian Dollendorf,
• Susanne Katharina Kreth,
• Soo Whan Choi and
• Helmut Ritter

Beilstein J. Org. Chem. 2013, 9, 453–459, doi:10.3762/bjoc.9.48

• 2 compared to 5,8-dichloro-1,4-dihydroxyanthraquinone (λmax = 500 nm) is a result of the enlargement of the π-electron system as aromatic moieties are introduced. This leads to absorption at longer wavelengths (bathochromic shift). Thus, the challenge of creating a green dye is to realize selective

The effect of the formyl group position upon asymmetric isomeric diarylethenes bearing a naphthalene moiety

• Renjie Wang,
• Shouzhi Pu,
• Gang Liu and
• Shiqiang Cui

Beilstein J. Org. Chem. 2012, 8, 1018–1026, doi:10.3762/bjoc.8.114

• nm respectively. In comparison with those of 1o–3o in hexane, the fluorescence emission peaks of 1o–3o in PMMA films consistently exhibited a remarkable bathochromic shift. The emission intensity of the ortho-substituted derivative 3o was the strongest, while that of the para-substituted derivative

Toward unidirectional switches: 2-(2-Hydroxyphenyl)pyridine and 2-(2-methoxyphenyl)pyridine derivatives as pH-triggered pivots

• Christina Tepper and
• Gebhard Haberhauer

Beilstein J. Org. Chem. 2012, 8, 977–985, doi:10.3762/bjoc.8.110

• else but a bathochromic shift of the band at 290 nm of 7 to higher wavelengths. The addition of tetrabutylammonium fluoride leads to the original spectrum. The bathochromic shift during the transition from 3-methylpyridine 7 to the protonated species 8 can be explained on the basis of time-dependent

• small coefficient at the protonated nitrogen atom, the energetic lowering of the HOMO (Δε = −3.89 eV) caused by the protonation is less pronounced than the one observed for the LUMO (Δε = −5.32 eV). The resulting decrease of the HOMO–LUMO gap is responsible for the bathochromic shift of the

• protonation of the methoxyphenylpyridine switch 10 with TFA leads to a bathochromic shift of the energetically lowest π→π* band in the UV and the CD spectrum. As the M isomer is present in solution in excess in relation to the P isomer, the whole process is unidirectional even if the extent (percentage) of

Synthesis, solid-state fluorescence properties, and computational analysis of novel 2-aminobenzo[4,5]thieno[3,2-d]pyrimidine 5,5-dioxides

• Kenichirou Yokota,
• Masayori Hagimori,
• Naoko Mizuyama,
• Yasuhisa Nishimura,
• Hiroshi Fujito,
• Yasuhiro Shigemitsu and
• Yoshinori Tominaga

Beilstein J. Org. Chem. 2012, 8, 266–274, doi:10.3762/bjoc.8.28

• λem,max values of 3a and 3c–g were in the range 430–462 nm. The fluorescence of the N-unsubstituted diamino compound 3b exhibited a large bathochromic shift, and green fluorescence was observed (λem,max = 529 nm). Compound 3a, which has an amino group at the 2-position in the pyrimidine ring, showed

• those of 3a–g. Compound 6 exhibited a large bathochromic shift compared with that of the benzo[4,5]thieno[3,2-d]pyrimidine 5,5-dioxides 3a and 3c–g, and relatively strong fluorescence. In contrast, the weakly fluorescent compound 7 exhibited a hypsochromic shift relative to 3a–g. These results

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

• and 1b revealed a bathochromic shift in the absorption maximum compared to the corresponding dialkyl end-capped sexithiophenes 2a and 2b (shifts of 10 and 12 nm for compounds 1a (λmax = 468 nm) and 1b (λmax = 469 nm), respectively (Figure 3; Table 2) [14]). These bathochromic shifts are consistent

Hyperbranched polyethylenimine bearing cyclodextrin moieties showing temperature and pH controlled dye release

• Indra Böhm,
• Susanne Katharina Kreth and
• Helmut Ritter

Beilstein J. Org. Chem. 2011, 7, 1130–1134, doi:10.3762/bjoc.7.130

• 1 (524 nm) decreases and a bathochromic shift is observed (Figure 4). Furthermore, a complete release (~1 mg of each dye from 5 mg of complex 6) of both dyes was achieved by heating the solution of complex 6 at pH 9–14 (Figure 4). Hence, two different components can be enclosed in one polymer and

Supramolecular FRET photocyclodimerization of anthracenecarboxylate with naphthalene-capped γ-cyclodextrin

• Qian Wang,
• Cheng Yang,
• Gaku Fukuhara,
• Tadashi Mori,
• Yu Liu and
• Yoshihisa Inoue

Beilstein J. Org. Chem. 2011, 7, 290–297, doi:10.3762/bjoc.7.38

• addition of 7 to an aqueous solution of AC (0.2 mM) caused an evident bathochromic shift of the 1La band of AC, which is probably due to the stacking complexation of two AC molecules in a single γ-CD cavity. Modified γ-CDs 6 and 7 showed moderate circular dichroism signals in the naphthalene-absorbing

Syntheses and properties of thienyl-substituted dithienophenazines

• Annemarie Meyer,
• Eva Sigmund,
• Friedhelm Luppertz,
• Gregor Schnakenburg,
• Immanuel Gadaczek,
• Thomas Bredow,
• Stefan-S. Jester and
• Sigurd Höger

Beilstein J. Org. Chem. 2010, 6, 1180–1187, doi:10.3762/bjoc.6.135

• coupling products with thiophene boronic acids. In both cases the thiophene units of the molecules act as electron rich parts (donors, D), whereas the phenazine moieties serve as electron deficient parts (acceptors, A), leading to a bathochromic shift of the UV–vis spectra in comparison with the non

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

• interactions. Quantum yield of fluorescence From Figure 3 and Figure 4 it is clear that with increasing solvent polarity, the intensity of emission decreases along with the bathochromic shift of the wavelength of emission. The fluorescence intensity of molecular systems that undergo efficient ICT upon