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

• )phenylamino)anthraquinone (5). In order to introduce polymerizable functionalities, 5 was treated with methacrylic chloride to give 1,4-bis(4-((2-methacryloxyethyl)oxy)phenylamino)anthraquinone (6) (Scheme 1, step c). The obtained blue chromophore 6 shows absorption maxima at 408, 600 and 644 nm in the UV–vis

• spectrum (Figure 1b). These maxima are located in the purple, orange and red color ranges, which results in combination to give the color blue. Analogous to the green dye, methacrylation of 5 does not influence the absorption maxima. Polymerizable red dyes 9, 12 and 15 based on anthraquinone A red

Inclusion of the insecticide fenitrothion in dimethylated-β-cyclodextrin: unusual guest disorder in the solid state and efficient retardation of the hydrolysis rate of the complexed guest in alkaline solution

• Dyanne L. Cruickshank,
• Natalia M. Rougier,
• Raquel V. Vico,
• Susan A. Bourne,
• Elba I. Buján,
• Mino R. Caira and
• Rita H. de Rossi

Beilstein J. Org. Chem. 2013, 9, 106–117, doi:10.3762/bjoc.9.14

• that the native β-CD and DIMEB show a negative and a positive peak (Figure 9a). The negative peaks appear at 320 and 324 nm and the positive ones at 260 and 265 nm for β-CD and DIMEB, respectively. The positive peak in the circular dichroism spectrum is slightly displaced from the maximum of the UV–vis

• spectrum as was observed in other cases where cyclodextrin was the chiral component [17][18][19][20]. The ICD spectrum of fenitrothion in the 200–300 nm wavelength range in the presence of β-CD was reported in the literature [21] and the spectrum shows a negative peak at ≈220 nm and a positive peak at ≈280

A bisazobenzene crosslinker that isomerizes with visible light

• Subhas Samanta,
• Harris I. Qureshi and
• G. Andrew Woolley

Beilstein J. Org. Chem. 2012, 8, 2184–2190, doi:10.3762/bjoc.8.246

• solution of 2 in DMSO-d6 containing a known concentration of 1,2-dichloroethane (DCE) as an internal reference was recorded. The NMR solution was later diluted in DMSO and the UV–vis spectrum was recorded to calculate the molar extinction coefficient. Molecular modeling: Models of trans,trans, trans,cis

Design and synthesis of a photoswitchable guanidine catalyst

• Philipp Viehmann and
• Stefan Hecht

Beilstein J. Org. Chem. 2012, 8, 1825–1830, doi:10.3762/bjoc.8.209

• spectroscopy (Figure 2). The UV–vis spectrum of guanidine 2E in acetonitrile exhibits the expected behavior, similar to the unsubstituted parent azobenzene, i.e., a low intensity n→π* band in the visible region and a much stronger π→π* band in the UV region of the spectrum. Note that the n→π* band partially

• to 61% by UPLC using a detection wavelength on the isosbestic point (290 nm). Based on this data, the UV–vis spectrum of the isomer 2Z was calculated (Figure 2d), assuming that the total absorption is the sum of the partial absorptions. Obviously, the significant hypsochromic shift of the π→π* band

A simple and efficient dual optical signaling chemodosimeter for toxic Hg(II)

• Sabir H. Mashraqui,
• Sapna A. Tripathi,
• Sushil S. Ghorpade and
• Smita R. Britto

Beilstein J. Org. Chem. 2012, 8, 1352–1357, doi:10.3762/bjoc.8.155

• Hg2+ induced a new blue-shifted maximum at 404 nm, while the probe’s maxima at 493 and 462 nm gradually diminished and disappeared at the limiting 2.83 × 10−4 M of Hg2+. At the limiting concentration of Hg2+, the final UV–vis spectrum was essentially similar to that of 1 [60], an observation that

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

• the case of the dansyl derivatives (8–10), two absorption peaks are observed at 253 and ca. 338 nm (Table 1). Compound 10 is also soluble in water; its UV–vis spectrum in this solvent is analogous to that in dioxane. It is important to note that there is no peak at 280 nm [12], meaning that no

• decrease of its fluorescence quantum yield (Φ) in water upon going from pure dioxane (Φ = 51) to pure water (Φ = 17), which cannot be related to protonation, as indicated from the UV–vis spectrum [10]. An analogous phenomenon was already described for a dansyl derivative of adenosine in solution in water

Predicting the UV–vis spectra of oxazine dyes

• Scott Fleming,
• Andrew Mills and
• Tell Tuttle

Beilstein J. Org. Chem. 2011, 7, 432–441, doi:10.3762/bjoc.7.56

• the basis for the single point excited state calculations. The six lowest singlet vertical excitation energies and oscillator strengths from the TD-DFT calculations were used to predict the UV–vis spectrum for each dye through the fitting of a Gaussian (with the GaussView default parameters for half

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

• shown in Figure 6C. Upon heating briefly to a higher temperature with a heat gun, the gel turned completely red, and the UV–vis spectrum (Figure 6D) showed two new strong peaks at 486 nm and 528 nm. After cooling the samples, part of the gel turned back to blue whilst the remainder stayed red. From

An enantiomerically pure siderophore type ligand for the diastereoselective 1 : 1 complexation of lanthanide(III) ions

• Markus Albrecht,
• Olga Osetska,
• Thomas Abel,
• Gebhard Haberhauer and
• Eva Ziegler

Beilstein J. Org. Chem. 2009, 5, No. 78, doi:10.3762/bjoc.5.78

• as CD spectroscopic titrations in methanol together with NaOH as base (10−4 M; Figure 4). Upon coordination of the metal ions to the ligand the transitions at the aromatic unit are influenced leading to changes in the UV–vis spectrum. In addition, metal coordination restricts the conformation at the