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Search for "platinum" in Full Text gives 187 result(s) in Beilstein Journal of Organic Chemistry.
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
- square planar platinum(II) complexes bearing π-conjugated chromophoric ligands playing a key role in such respect. In this contribution, the most recent and promising trends in the field of phosphorescent platinum complexes will be reviewed and discussed. In particular, the importance of proper molecular
- ; 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
- including photocatalysis [6], bio-imaging [7][8], and solar-energy conversion [9], just to cite a few. Thompson and Forrest reported in 1998 on the first example of a phosphorescent emitter, namely 2,3,7,8,12,13,17,18-octaethyl-21H,23H-porphyrin platinum(II) (Pt(OEP)), used as dopant for the fabrication of
An overview of recent advances in duplex DNA recognition by small molecules
Beilstein J. Org. Chem. 2018, 14, 1051–1086, doi:10.3762/bjoc.14.93
Polysubstituted ferrocenes as tunable redox mediators
Beilstein J. Org. Chem. 2018, 14, 1004–1015, doi:10.3762/bjoc.14.86
- (time-dependent) density functional theoretical (TD)-DFT methods. Results and Discussion Electrochemistry of esters 1–4 The esters 1–4 were studied by cyclic and square wave voltammetry in 0.1 M CH2Cl2 solutions of [n-Bu4N][B(C6F5)4], using platinum working and counter electrodes. All esters 1–4 show an
- carried out on a BioLogic SP-50 voltammetric analyzer using a platinum working electrode, a platinum wire as counter electrode, and a 0.01 M Ag/AgNO3 CH3CN electrode as reference electrode. The measurements were carried out at a scan rate of 100 mV s−1 for cyclic voltammetry experiments and 100 mV s−1 for
On the design principles of peptide–drug conjugates for targeted drug delivery to the malignant tumor site
Beilstein J. Org. Chem. 2018, 14, 930–954, doi:10.3762/bjoc.14.80
- with the German Gynecological Oncology Group (AGO) and 3 other centers from Bulgaria on 43 women. The patients had platinum-resistant advanced ovarian cancer, FIGO (Fédération Internationale de Gynécologie et d'Obstétrique) III or IV or recurrent endometrial cancer (EC) and LHRH receptor-positive tumor
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
- the supporting electrolyte. The cyclic voltammograms are shown in Figure 3. Cyclic voltammetry was measured with a glassy carbon working electrode, a platinum wire counter electrode, a saturated Ag/AgCl reference electrode, ferrocenium-ferrocene (Fc+/Fc) as the internal standard and tetrabutylammonium
D–A–D-type orange-light emitting thermally activated delayed fluorescence (TADF) materials based on a fluorenone unit: simulation, photoluminescence and electroluminescence studies
Beilstein J. Org. Chem. 2018, 14, 672–681, doi:10.3762/bjoc.14.55
- %, when assuming the out-coupling efficiency to be 20%. On the other hand, phosphorescent materials could utilize triplet excitons in electroluminescence processes to achieve 100% IQEmax [2][3]. However, the utilization of metals like iridium and platinum, which are expensive and nonrenewable, inevitably
- NMR spectra were measured on a Bruker NMR spectrometer with tetramethylsilane (TMS) as the internal standard. TGA and DSC measurements were performed on a Netzsch TG 209 and a Netzsch DSC 209 under N2, respectively. A CHI600D electrochemical work station with a platinum working electrode and a
- platinum wire counter electrode at a scanning rate of 100 mV s−1 against a Ag/Ag+ (0.1 M of AgNO3 in acetonitrile) reference electrode were utilized for cyclic voltammetry measurements. UV–vis absorption spectra were measured using a HP 8453 spectrophotometer and PL and LTPL spectra were measured with a
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
- Rebecca Pittkowski Thomas Strassner Physical Organic Chemistry, Technische Universität Dresden, Bergstraße, 01069 Dresden, Germany 10.3762/bjoc.14.54 Abstract Luminescent organometallic platinum(II) compounds are of interest as phosphors for organic light emitting devices. Their emissive
- β-diketonates on the emission properties of C^C* cyclometalated complexes, employing the unsubstituted methyl-phenyl-imidazolium ligand. The quantum yield was significantly enhanced by changing the auxiliary ligand from acetylacetonate, where the corresponding platinum(II) complex shows only a very
- weak emission, to mesityl (mes) or duryl (dur) substituted acetylacetonates. The new complexes show very efficient emission with quantum yields >70% in the sky-blue spectral region (480 nm) and short decay times (<3 μs). Keywords: ancillary ligand; β-diketonates; photoluminescence; platinum(II
Mannich base-connected syntheses mediated by ortho-quinone methides
Beilstein J. Org. Chem. 2018, 14, 560–575, doi:10.3762/bjoc.14.43
- –platinum(II) complexes [94]. Both DNA binding and topoisomerase I inhibition studies proved that the coordination and stabilization of the quinone methide structure can effect marked changes in DNA reactivity. In a recent publication, 3-(aminomethyl)naphthoquinones were investigated from the point of view
An alternative to hydrogenation processes. Electrocatalytic hydrogenation of benzophenone
Beilstein J. Org. Chem. 2018, 14, 537–546, doi:10.3762/bjoc.14.40
- electrocatalytic hydrogenation of benzophenone has not been accomplished using a PEMER yet. This work aims at exploring the electrocatalytic hydrogenation of benzophenone over palladium nanoparticles supported on carbon black based electrode using a PEMER. A nanoparticulate platinum gas diffusion electrode is used
- acted as a working electrode (WE), the counter electrode was a platinum wire and an Ag/AgCl (3.0 M KCl) acted as reference electrode through a Luggin capillary. CV measurements were performed at room temperature and under argon atmosphere. CV curves were recorded between 0.1 and 1.2 V vs Ag/AgCl (3.0 M
The selective electrochemical fluorination of S-alkyl benzothioate and its derivatives
Beilstein J. Org. Chem. 2018, 14, 389–396, doi:10.3762/bjoc.14.27
- electrolytic conditions. Electrolysis was performed at a constant current (40 mA) with platinum electrodes (2 cm × 2 cm) in several solvents containing various fluoride salts in an undivided cell at room temperature and current was passed basically until 1a was consumed. The results are summarized in Table 1
- current power supply model 5944 by monitoring electricity with a Hokutodenko Coulomb/Ampere-hour meter HF-201. Cyclic voltammetry measurements Cyclic voltammetry was carried out in 0.1 M Bu4NBF4/MeCN using a glass cell. A platinum disk electrode ( = 0.8 mm) was used as a working electrode. A platinum
- oxidation of a substrate (1 mmol) was carried out in a plastic undivided cell equipped with platinum anode and cathode (2 cm × 2 cm) containing 10 mL of HF salt (20 equiv of F− to substrate/solvent) at room temperature. A constant current (40 mA) was passed until the starting material was mostly consumed
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
- % for phosphorescent OLEDs [5]. As drawback, triplet emitters are transition-metal complexes mostly based on iridium, platinum and osmium and the scarcity of these metals on Earth, their toxicity and high cost make these materials unsuitable candidates for a mass-production of OLEDs [6]. However
From dipivaloylketene to tetraoxaadamantanes
Beilstein J. Org. Chem. 2018, 14, 1–10, doi:10.3762/bjoc.14.1
- and ethyl esters were determined by X-ray crystallography [19]. The X-ray structure of the Pt(II) chelate of tetramethyl 2,6,9-trioxabicyclo[3.3.1]nona-3,7-diene obtained from tris-acetylacetonato platinum(II) was determined previously [22][23], and the separation of the enantiomers of the free ligand
Structure–property relationships and third-order nonlinearities in diketopyrrolopyrrole based D–π–A–π–D molecules
Beilstein J. Org. Chem. 2017, 13, 2374–2384, doi:10.3762/bjoc.13.235
- ). Electrochemistry Electrochemical measurements of all target compounds were carried out in N,N-dimethylformamide containing 0.1 M Bu4NPF6 in a three electrode cell by cyclic voltammetry (CV) and rotating disk voltammetry (RDV). The working electrode was a platinum disk (2 mm in diameter) for CV and RDV experiments
The effect of milling frequency on a mechanochemical organic reaction monitored by in situ Raman spectroscopy
Beilstein J. Org. Chem. 2017, 13, 2160–2168, doi:10.3762/bjoc.13.216
- Bruker Vertex 70 FT-IR Platinum ATR, while X-ray powder diffraction patterns were collected on a Proto Manufacturing AXRD Benchtop Powder Diffractometer using Ni-filtered Cu Kα radiation. The conversion for each solid-state reaction was evaluated after milling using 1H NMR spectroscopy conducted in CDCl3
Solid-state studies and antioxidant properties of the γ-cyclodextrin·fisetin inclusion compound
Beilstein J. Org. Chem. 2017, 13, 2138–2145, doi:10.3762/bjoc.13.212
- continuous mode in the 3.5° ≤ 2θ ≤ 50° interval. TG studies were performed on a Shimadzu TGA-50 thermogravimetric analyzer, using a heating rate of 5 °C min−1, under air atmosphere, with a flow rate of 20 mL min−1. The sample holder was a 5 mm in diameter platinum plate and the sample mass was about 5 mg
An effective Pd nanocatalyst in aqueous media: stilbene synthesis by Mizoroki–Heck coupling reaction under microwave irradiation
Beilstein J. Org. Chem. 2017, 13, 1717–1727, doi:10.3762/bjoc.13.166
- reactions has been reported, using a phase-transfer agent and focusing on the employment of ultralow catalyst concentrations [45]. Recently, we reported the electrochemical synthesis of stable Pd NPs by using platinum or vitreous carbon electrodes at room temperature via direct electroreduction of aqueous
- -Pd NPs of a mean diameter of 10 nm were obtained using a platinum electrode, characterized as previously reported, and used without additional purification [46][47]. In a previous work the PVP-Pd NPs synthesized using a vitreous carbon electrode were tested on the Mizoroki–Heck reaction with 4-iodo
- the stabilizing agent under solution stirring. The galvanostatic synthesis of Pd NPs was performed by applying to the platinum electrode a current density pulse from 0 to a cathodic value of 150 mA/cm2, during 600 s. Vigorous stirring of the solution (1000 rpm) with a magnetic stirrer was kept during
Oxidative dehydrogenation of C–C and C–N bonds: A convenient approach to access diverse (dihydro)heteroaromatic compounds
Beilstein J. Org. Chem. 2017, 13, 1670–1692, doi:10.3762/bjoc.13.162
- combination of heterogeneous polymer-supported bi-metallic platinum/iridium alloyed nanoclusters and 5,5’,6,6’-tetrahydroxy-3,3,3’,3’-tetramethyl-1,1’-spiro-bisindane (TTSBI) facilitated a one-pot condensation and oxidative dehydrogenation of o-aminobenzylamine to generate quinazoline derivatives 79 under
- dehydrogenation of tetrahydroisoquinolines. Ruthenium-catalyzed polycyclic heteroarenes. Plausible mechanism of the ruthenium-catalyzed dehydrogenation. Bi-metallic platinum/iridium alloyed nanoclusters and 5,5’,6,6’-tetrahydroxy-3,3,3’,3’-tetramethyl-1,1’-spiro-bisindane (TTSBI) for the synthesis of quinazolines
Synthesis of alkynyl-substituted camphor derivatives and their use in the preparation of paclitaxel-related compounds
Beilstein J. Org. Chem. 2017, 13, 1230–1238, doi:10.3762/bjoc.13.122
- platinum(II). The formed product structures depend not only on the reagents used but also on the substituents attached to the triple bonds. Cycloisomerisations with perfect atom economy lead to polycyclic heterocycles that resemble to some extent the AB ring system of paclitaxel. Herein, we present
- ; platinum; Introduction Enantiomerically pure raw materials, available in a sustainable manner from the natural “chiral pool” [1], offer a convenient entrance for the chemical synthesis of other chiral compounds, e.g., rare natural products and their analogues [2], or chiral catalysts [3][4]. A prominent
- leading to a product resembling paclitaxel to some extent was found in both cases. However, one of the isomers yielded a second product lacking the ring-enlargement step and containing an additional sulphur–oxygen–carbon linkage. The platinum complex of this compound was postulated before as an
Glyco-gold nanoparticles: synthesis and applications
Beilstein J. Org. Chem. 2017, 13, 1008–1021, doi:10.3762/bjoc.13.100
- , hosting methotrexate (MTX), an anticancer drug. The anticancer therapy based on platinum compounds, such as cisplatin, carboplatin and oxaliplatin, has many positive effects on the regression of cancer cell proliferation. Unfortunately these compounds are low tolerated by the organisms, therefore new
Continuous-flow processes for the catalytic partial hydrogenation reaction of alkynes
Beilstein J. Org. Chem. 2017, 13, 734–754, doi:10.3762/bjoc.13.73
- alternative to palladium, a 1 wt % platinum catalyst supported onto calcium carbonate was also reported, however, with no practical advantages over Pd in terms of partial hydrogenation (27% ene selectivity at 78% conversion and 373 K) [173]. Methyl phenylpropiolate and 4-phenyl-3-butyn-2-one The continuous
Diastereoselective anodic hetero- and homo-coupling of menthol-, 8-methylmenthol- and 8-phenylmenthol-2-alkylmalonates
Beilstein J. Org. Chem. 2017, 13, 33–42, doi:10.3762/bjoc.13.5
- anodic decarboxylation of five malonic acid derivatives. These were prepared from benzyl malonates and four menthol auxiliaries. Coelectrolyses with 3,3-dimethylbutanoic acid in methanol at platinum electrodes in an undivided cell afforded hetero-coupling products in 22–69% yield with a
- purity (Scheme 1). Anodic hetero-coupling of carboxylates Carboxylates of aliphatic carboxylic acids are oxidized to carbonyloxy radicals at a platinum electrode at potentials being generally higher than 2.0 V (vs NHE). The carbonyloxy radicals undergo fast decarboxylation to alkyl radicals at or near
- for constant temperature control, capacity: 3 mL (micro beaker-type cell). Platinum foils serving as anode and cathode materials (platinum foils: 1 × 1 cm). Convection was achieved by magnetic stirring. Current source: Heinzinger galvanostat – potentiostat HN 600–600 and TNs 300–1500. General
Organometallic chemistry
Beilstein J. Org. Chem. 2016, 12, 2216–2221, doi:10.3762/bjoc.12.213
- -butylphosphino)methane (dtbpm) were a unique feature of his work [61][67][70][71][72][80][81][84][86][93][94][97][100][101][103][107][124][128][148][149] that ultimately enabled C–Si activation of organosilanes and the C–C activation of oxiranes by coordinatively unsaturated platinum species [66][149]. In the
Palladium-catalyzed ring-opening reactions of cyclopropanated 7-oxabenzonorbornadiene with alcohols
Beilstein J. Org. Chem. 2016, 12, 2189–2196, doi:10.3762/bjoc.12.209
- the use of platinum catalysts [19] or palladium catalysts with zinc co-catalyst with phenol nucleophiles [20]. Meanwhile, anti-stereoisomeric products 5 and 6 are obtained when copper catalysts are used with alkyl nucleophiles [21], if rhodium [22] or iridium catalysts are used in the presence of
- result in no reaction, the optimized catalyst was used with an external source of triphenylphosphine, which resulted in no reaction (Table 1, entry 12). To expand the scope of catalyst, the effect of using a platinum catalyst was investigated. The use of a platinum(IV) catalyst resulted in no reaction
- (Table 1, entry 13) along with the use of a platinum(II) catalyst (Table 1, entry 14). Using an anionic platinum(II) catalyst yielded substituted naphthalene 11a in a 22% yield, though this was considerably lower when compared to the optimized palladium catalyst. A variety of solvents were next screened
Solvent-free synthesis of novel para-menthane-3,8-diol ester derivatives from citronellal using a polymer-supported scandium triflate catalyst
Beilstein J. Org. Chem. 2016, 12, 2046–2054, doi:10.3762/bjoc.12.193
- gas. The samples were analysed by using the following method; injector temperature 250 °C, helium flow rate 0.1 mL·min−1, oven temperature 70 °C for 5 min and then ramped to 280 °C at 10 °C min−1 with split flow ratio of 60 mL·min−1. The FTIR characteristic peaks were recorded on a Bruker Platinum
Synthesis and characterization of fluorinated azadipyrromethene complexes as acceptors for organic photovoltaics
Beilstein J. Org. Chem. 2016, 12, 1925–1938, doi:10.3762/bjoc.12.182
- tetra-n-butylammonium hexafluorophosphate (TBAPF6) in DCM. Ferrocene/ferrocenium was used as an internal standard and was purified prior to use by sublimation. A typical three-electrode configuration was used, with a glassy carbon electrode as the working electrode and two platinum wires used as the
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