- Bodipy dyes bearing oligo(ethylene glycol) groups on the meso-phenyl ring: Tuneable solid-state photoluminescence and highly efficient OLEDs
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Borondipyrromethene (Bodipy) dyes with strong solid-state photoluminescence are highly desirable for their applications in OLEDs. In this work, a series of meso-(4-R-C6H4)-substituted Bodipy dyes (R = H for B1; R = (OCH2CH2)nOCH2CH3, n = 0-3 for B2-B5, respectively) were prepared through an acid-catalyzed reaction. The flexible ether groups attached to the periphery of B2-B5 are expected to influence the molecular arrangement and intermolecular interactions in solid state. Crystallographic analysis of B1-B4 reveals that the meso-phenyl ring is almost orthogonal to the indacene plane. Intermolecular π-π interactions are observed in B1 but absent in B2-B4. As a consequence, the dye B1 is weakly emissive in solid state, while B2-B4 emit strongly in the red region with emission quantum yields of up to 0.33. The PMMA films doped with B2 show two separated emission peaks, and their relative intensity is concentration dependent, leading to the fluorescence color varying from greenish yellow to red as the concentrations successively increased from 5 to 80 wt%. The formation of dimers in the ground state is found to be responsible for the red emission in the condensed state. Efficient OLEDs were fabricated by doping 2 wt% B2-B4 as emitters and gave high luminance, current efficiency, and external quantum efficiency of up to 920 cd m-2, 8.00 cd A-1, and 2.15%, respectively. This journal is the Partner Organisations 2014.
- Liu, Cui-Lian,Chen, Yong,Shelar, Deepak P.,Li, Cong,Cheng, Gang,Fu, Wen-Fu
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supporting information
p. 5471 - 5478
(2014/07/08)
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- Further insights into the chemistry of niobium and tantalum pentahalides with 1,2-dialkoxyalkanes: Synthesis of bromo- and iodoalkoxides, spectroscopic and computational studies
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The room temperature reactions of a series of 1,2-dialkoxyalkanes ROCH 2CH(R′)OR′′ with MX5 (M = Nb, Ta; X = Br, I) in 1:1 ratio result in single C-O bond cleavage and high-yield formation of the halo-alkoxides MBr4[κ2-OCH 2CH(R′)OR′′] or [NbI4{κ 1-OCH2CH(R′)OR′′}]2, and equimolar amounts of the corresponding alkyl halides RX. The reaction of NbBr5 with 1,2-dimethoxyethane, dme, proceeds with preliminary formation of the ionic species [NbBr4(κ2-dme) (κ1-dme)][NbBr6], 3b, which has been identified by solution NMR at low temperature and conductivity analyses. The gas-phase structure of 3b has been optimized by DFT calculations, confirming that the dme ligands adopt bidentate and monodentate coordination, respectively. Although the formation of NbOBr3(dme), 4b, 1,4-dioxane and MeBr from NbBr 5/dme (ratio 1:2) is an exoergonic process (calculated ΔGr° = -115.96 kcal mol-1), it is inhibited at room temperature. High temperature conditions enhance the production of 1,4-dioxane at the expense of selectivity. The dinuclear species NbOBr3(dme)NbBr5 (Nb-O-Nb), 5b, (X-ray) has been isolated in modest yield as byproduct of the room temperature reaction of NbBr5 with dme. In general, the 1:2 molar reactions of NbX5 (X = Br, I) with ROCH2CH(R′) OR′′ occur with the exclusion of nearly one equivalent of organic reactant.
- Bini, Riccardo,Marchetti, Fabio,Pampaloni, Guido,Zacchini, Stefano
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experimental part
p. 1412 - 1419
(2011/06/22)
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- PROCESS FOR PRODUCING 2-ALKOXYETHYL BROMIDE
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A process for 2-alkoxyethyl bromide production which comprises reacting a 2-alkoxyethanol with thionyl bromide in the presence of one or more compounds having an amide or urea bond in the molecule, the one or more compounds being used in an amount of at least 0.8 mole equivalents per mole of the 2-alkoxyethanol. By the process, a high-purity 2-alkoxyethyl bromide can be produced in a high yield while inhibiting the generation of impurities as by-products.
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Page/Page column 8-9; 1/1
(2008/06/13)
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- Triphenylphosphine/2,3-dichloro-5,6-dicyanobenzoquinone as a new, selective and neutral system for the facile conversion of alcohols, thiols and selenols to alkyl halides in the presence of halide ions
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A mixture of triphenylphosphine (Ph3P) and 2,3-dichloro-5,6-dicyanobenzoquinone in CH2Cl2 affords a complex which in the presence of R4NX (X=Cl, Br, I) converts alcohols, thiols and selenols into their corresponding alkyl halides in high yields at room temperature. The method is highly selective for the conversion of 1° alcohols in the presence of 2° ones and also 1° and 2° alcohols in the presence of 3° alcohols, thiols, epoxides, trimethylsilyl- and tetrahydropyranyl ethers, 1,3 dithianes, disulfides, and amides.
- Iranpoor,Firouzabadi,Aghapour,Vaez zadeh
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p. 8689 - 8693
(2007/10/03)
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- Novel 2-bromoethyl tellurium bromides
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The novel bis (2-bromoethyl) tellurium dibromide and 2-bromoethyl tellurium tribromide are prepared by reacting ethylene with a source of tellurium tetrabromide in an inert, non-basic organic solvent under certain temperature conditions and in the substantial absence of molecular oxygen.
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