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Search for "phosphorescence" in Full Text gives 42 result(s) in Beilstein Journal of Organic Chemistry.
Fluorescent phosphorus dendrimers excited by two photons: synthesis, two-photon absorption properties and biological uses
Beilstein J. Org. Chem. 2019, 15, 2287–2303, doi:10.3762/bjoc.15.221
- phosphorescence of certain minerals after being exposed to sun light, have fascinated Men for a long time. An important part of luminescence phenomena is due to the influence of light (generally visible or ultra-violet light) on matter, such as for instance a molecule, which can emit light at a wavelength
- intersystem conversion towards a triplet state (T1), from which there will be emission of phosphorescence, having generally a lifetime longer than that of fluorescence. This classical one-photon excited fluorescence has led to the design of numerous types of chemical entities since the XIX century. For
Complexation of a guanidinium-modified calixarene with diverse dyes and investigation of the corresponding photophysical response
Beilstein J. Org. Chem. 2019, 15, 1394–1406, doi:10.3762/bjoc.15.139
- singlet state 1MLCT can undergo ultrafast intersystem crossing leading to the formation of the triplet state 3MLCT which could emit phosphorescence. Ru(dcbpy)3 was employed as a representative candidate in this work to study the photophysical response upon complexation with GC5A. Almost no appreciable
Applications of organocatalysed visible-light photoredox reactions for medicinal chemistry
Beilstein J. Org. Chem. 2018, 14, 2035–2064, doi:10.3762/bjoc.14.179
- efficiency of the PET process. The decay of T1 is negligible as the processes which bring this about (phosphorescence mainly) are symmetry forbidden and hence very slow. Therefore, if a molecule can reach the T1 state through excitation with visible light then it is one which can be considered as a
Recent advances in phosphorescent platinum complexes for organic light-emitting diodes
Beilstein J. Org. Chem. 2018, 14, 1459–1481, doi:10.3762/bjoc.14.124
- ; electroluminescence; OLED; phosphorescence; platinum complexes; Introduction Photoactive TMCs have attracted enormous attention in the last two decades because of their peculiar photophysical and rich redox properties, which make them appealing from both fundamental research and technological applications points of
- between hundreds of nanoseconds to several microseconds, constituting a formally spin-forbidden transition (phosphorescence). Structural modification of the TMCs and proper tailoring of coordinated ligands can independently act on the nature, energy and topology of frontier orbitals. In fact, a fine
- supplementary interactions reinforced the ligand–metal bond, which explains well the remarkable phosphorescence efficiency obtained in solid-state thin films being PLQY of 0.52 and 0.83 for 8 and 9, respectively. Such findings prompted the authors to fabricate non-doped OLEDs with an architecture as follows
Two novel blue phosphorescent host materials containing phenothiazine-5,5-dioxide structure derivatives
Beilstein J. Org. Chem. 2018, 14, 869–874, doi:10.3762/bjoc.14.73
- as suitable HOMO and LUMO energy levels. This preferable performance suggests that CEPDO and CBPDO are alternative bipolar host materials for the PhOLEDs. Keywords: host materials; phenothiazine; phosphorescence; synthesis; Introduction Since 1987, the Tang group [1] firstly reported double organic
- phosphorescence (77 K) spectra of CEPDO (a) and CBPDO (b) in solution, respectively. Obviously, the strong absorption peak at 236 nm can be ascribed to the π→π* transition of carbazole moiety of the molecules, and the weaker absorptions around 295 nm assign to the n→π* transition of the conjugation of the whole
- the triplet energy level, their low-temperature Phos spectra were measured in a 2-methyltetrahydrofuran solution at 77 K which are also shown in Figure 2. The phosphorescence emission peaks were at 440 nm and 439 nm, respectively. According to the onset of their phosphorescence spectra, the calculated
Enhanced quantum yields by sterically demanding aryl-substituted β-diketonate ancillary ligands
Beilstein J. Org. Chem. 2018, 14, 664–671, doi:10.3762/bjoc.14.54
- ) are shorter compared to the phosphorescence decay of the α-duryl-substituted complex (8.7 µs at 77 K in 2-MeTHF). The observed effects can be attributed to a major influence of the counter ligand on the emission characteristics, which is further supported by the localization of spin density almost
- phosphorescence decay of all complexes was measured with an Edinburgh Instruments mini-τ by excitation with a pulsed EPLED (360 nm, 20 kHz) and time-resolved photon counting (TCSPC). Frozen 2-MeTHF glass emission samples at 77 K were prepared by inserting a sealed quartz tube, containing the solution under argon
Recent advances on organic blue thermally activated delayed fluorescence (TADF) emitters for organic light-emitting diodes (OLEDs)
Beilstein J. Org. Chem. 2018, 14, 282–308, doi:10.3762/bjoc.14.18
- singlet excited states by reverse intersystem crossing (RISC). By harvesting both singlet and triplet excitons for light emission, OLEDs competing and sometimes overcoming the performance of phosphorescence-based OLEDs could be fabricated, justifying the interest for this new family of materials massively
- 88.4° for the dihedral angle between the phenylene and the 9,9-dimethylacridane unit in B2. ΔEST values of 0.013 eV and 0.041 eV were experimentally determined for B1 and B2, respectively, calculated from the difference existing between the onset of the fluorescence and the phosphorescence emission
- OLEDs producing a deep blue emission with CIE coordinates of (0.15, 0.07) were fabricated (see Figure 3). Examination of the phosphorescence spectra of D1–D3 at 77 K revealed their T1 states to be 3ππ* states centred on their electron-donating parts. ΔEST values of 0.54, 0.45 and 0.32 eV were
One-pot syntheses of blue-luminescent 4-aryl-1H-benzo[f]isoindole-1,3(2H)-diones by T3P® activation of 3-arylpropiolic acids
Beilstein J. Org. Chem. 2017, 13, 2340–2351, doi:10.3762/bjoc.13.231
- pattern of the naphthalene scaffold. Even the smallest polarity change in the solvent system effects their absorption and emission behavior [34][40]. Very recent investigations on naphthaleneimide derivatives revealed enormous phosphorescence lifetimes that are particularly interesting for imaging
Novel β-cyclodextrin–eosin conjugates
Beilstein J. Org. Chem. 2017, 13, 543–551, doi:10.3762/bjoc.13.52
- oxygen. Although several indirect methodologies based on suitable chemical traps are well known to detect 1O2 formation, the best experimental method to prove and quantify its production is its direct detection. It is based on the monitoring of the typical phosphorescence of 1O2 in the near-IR spectral
Supramolecular polymer assembly in aqueous solution arising from cyclodextrin host–guest complexation
Beilstein J. Org. Chem. 2016, 12, 50–72, doi:10.3762/bjoc.12.7
- interesting aspect is that because the α-bromonaphthalene substituents occupy the hydrophobic β-CD annuli in the hydrogel, UV radiation induces room temperature phosphorescence which, in combination with the self-healing properties of the hydrogel, may lead to some interesting applications. The change of
Photo, thermal and chemical degradation of riboflavin
Beilstein J. Org. Chem. 2014, 10, 1999–2012, doi:10.3762/bjoc.10.208
- triplet state. These excited states eventually return to the ground state by emitting fluorescence, phosphorescence or heat. The falling back of these states to the ground state may be due to self-quenching of the RF molecule (internal quencher) or its photoproducts. Often external quenchers are added to
Expeditive synthesis of trithiotriazine-cored glycoclusters and inhibition of Pseudomonas aeruginosa biofilm formation
Beilstein J. Org. Chem. 2014, 10, 1981–1990, doi:10.3762/bjoc.10.206
- trithiotriazine-based ligands. Results and Discussion Design of ligands A previous study from our laboratories [30] has shown that low-valent glycoasterisk ligands based on a persulfurated benzene core [31][32] could have a dual role as a probe and as a ligand, due to their phosphorescence [33] and
Synthesis, characterization and luminescence studies of gold(I)–NHC amide complexes
Beilstein J. Org. Chem. 2013, 9, 2216–2223, doi:10.3762/bjoc.9.260
- . Lifetimes for all luminescence measurements were ≤1 μs (at the limit of the apparatus), suggesting that the luminescence was due to fluorescence, rather than phosphorescence. The wavelengths of emission maxima spans the range 390 to 516 nm, demonstrating that by selecting the appropriate amine ligand the
Studies on the photodegradation of red, green and blue phosphorescent OLED emitters
Beilstein J. Org. Chem. 2013, 9, 2088–2096, doi:10.3762/bjoc.9.245
- is supported by comparing the normalized phosphorescence spectra after consecutive irradiation periods (Figure 5). A hypsochromic shift and signal broadening with increased irradiation times is observed, indicating the presence of other species contributing to the emission. In fact, the HPLC–DAD
- via the ratio of the integrated phosphorescence spectra after irradiation to its initial value. Structures of the investigated phosphorescent triscyclometalated iridium complexes. Photodegradation of the different compounds in toluene under ambient atmosphere. Plotted is the ratio between the
- Ir(piq)3 in benzene and benzene-d6 under ambient and inert conditions (left). Hypsochromic shift of the phosphorescence of an Ir(piq)3-doped PMMA film with increased irradiation time (right). DAD chromatogram showing the formation of two main degradation products (left) and their assigned mass
Topochemical control of the photodimerization of aromatic compounds by γ-cyclodextrin thioethers in aqueous solution
Beilstein J. Org. Chem. 2013, 9, 1858–1866, doi:10.3762/bjoc.9.217
- with heavy atoms attached, e.g., 6-deoxy-iodo-CDs, are known to even enable room temperature phosphorescence of an excited guest [36]. (b) Moreover, according to the results of the quantum mechanical calculations [25][34] the preferential anti-parallel alignment of the ACE dimer within the CD cavity
Electron and hydrogen self-exchange of free radicals of sterically hindered tertiary aliphatic amines investigated by photo-CIDNP
Beilstein J. Org. Chem. 2013, 9, 437–446, doi:10.3762/bjoc.9.46
- radical pairs lie well below those of the sensitizer triplets. The saturated amine DABCO possesses an even higher triplet energy (about 360 kJ/mol, as estimated from the phosphorescence in frozen matrices [37]) than the sensitizers, so the radical pairs can only react back to the starting materials via
Photoinduced electron-transfer chemistry of the bielectrophoric N-phthaloyl derivatives of the amino acids tyrosine, histidine and tryptophan
Beilstein J. Org. Chem. 2011, 7, 518–524, doi:10.3762/bjoc.7.60
- photophysical and photochemical properties of N-phthaloylvaline methyl ester (1) have been studied by nanosecond laser flash photolysis (λexc = 248 or 308 nm) [5]. The quantum yield of fluorescence is low (ФF = 10−2), whereas that of phosphorescence at −196 °C is large (0.5). The triplet properties of 1 at room
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