- Structural identification of the factors that prevent an electronic spin-state crossover in Fe[(C6H5)B(3-Mepz)3]2 (pz = pyrazolyl ring)
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The synthesis, structural, magnetic, and M?ssbauer spectral properties of Fe[(C6H5)B(3-Mepz)3]2 (2, pz = pyrazolyl ring) are reported. The single crystal X-ray structural results indicate that at both 294 and 90 K Fe[(C6H5)B(3-Mepz)3]2 (2) has a distorted octahedral iron(II) coordination environment with Fe-N bond distances that average ca. 2.18 ?, distances that clearly indicate the high-spin nature of the complex at these temperatures. Both the magnetic and M?ssbauer spectral results indicate that Fe[(C6H5)B(3-Mepz)3]2 (2) remains high-spin down to 4 K. This result is surprising because the closely related Fe[(p-R-C6H4)B(3-Mepz)3]2 [R = I, {single bond}C{triple bond, long}C{single bond}H, {single bond}C{triple bond, long}C{single bond}SiMe3, or {single bond}C{triple bond, long}C{single bond}C6H5] complexes do exhibit electronic spin-state changes on cooling. The absence of a spin-state crossover in Fe[(C6H5)B(3-Mepz)3]2 (2) is the result of its molecular structure in which the three pyrazolyl rings of each tridentate ligand are highly twisted away from an ideal C3v coordination symmetry, a twisting distortion that favors the high-spin form of the complex with longer Fe-N bond distances.
- Reger, Daniel L.,Elgin, J. Derek,Smith, Mark D.,Grandjean, Fernande,Rebbouh, Leila,Long, Gary J.
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Read Online
- Functionalization of Bis-Diazaphospholene P–P Bonds with Diverse Electrophiles
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Phosphorus-sp3 or -sp2 carbon bonds are readily formed by the reaction of bis-diazaphospholenes with several classes of electrophiles. These reactions result in cleavage of the phosphorus–phosphorus bond and formation of functionalized diazaphospholenes. The reactions proceed rapidly, without catalysis. Experimental evidence with aryl and alkyl halides suggests the intermediacy of radicals in some cases, however other evidence suggests either radical or polar mechanisms may be operative for certain substrates, with a dependence on reaction conditions. In three cases, the product aryl diazaphospholenes have been shown to transfer the aryl substituent to electrophiles. These results reveal that diazaphospholene dimers are potent participants in radical chemistry with organic substrates at room temperature without requiring chemical initiators.
- Huchenski, Blake S. N.,Robertson, Katherine N.,Speed, Alexander W. H.
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supporting information
p. 5140 - 5144
(2020/07/27)
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- Triazole derivative containing boron-nitrogen group, polymer and preparation methods and applications of triazole derivative and polymer
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The invention belongs to the technical field of organic photoelectricity, and discloses a triazole derivative containing a boron-nitrogen group, a polymer and preparation methods and applications of the triazole derivative and the polymer. The chemical st
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Paragraph 0052; 0061-0062
(2020/07/07)
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- Structural and spectroscopic analysis of a new family of monomeric diphosphinoboranes
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We present a series of amino- and aryl(diphosphino)boranes R2PB(R′′)PR′2, where R2P, R′2P = tBu2P, tBuPhP, Ph2P, Cy2P, and R′′ = iPr2N, Ph, which were obtained via the
- Ordyszewska, Anna,Szynkiewicz, Natalia,Perzanowski, Emil,Chojnacki, Jaros?aw,Wi?niewska, Aleksandra,Grubba, Rafa?
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p. 12482 - 12495
(2019/08/26)
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- The preparation of pentafluorophenyldihaloboranes from pentafluorophenylmercurials C6F5HgR and BX3: the dramatic dependence of the reaction direction on the ligand R
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Abstract: In search of convenient preparations of C6F5BX2 (X = Cl, Br), reactions of C6F5HgR (R = C6F5, C6H5, C2H5, Br and Cl) with BX3 were studied. Under the action of BCl3 the order of the C–Hg bond cleavage is C6F5Hg–C6H5 > C6F5–HgC2H5 > C6F5–HgC6F5 >> C6F5–HgCl. With more reactive BBr3 the sequence is C6F5Hg–C6H5 > C6F5–HgC2H5 ~ C6F5Hg–C2H5 > C6F5–HgC6F5 ≥ C6F5–HgBr. During the study we found the simple way to alkyldibromoboranes which is presented by the preparation of C2H5BBr2 from C2H5HgBr and BBr3. It is the second example of synthesis of alkylmercury derivative in an addition to the earlier reported formation of cyclopropylmercurials from di(cyclopropyl)mercury and BX3. Graphic abstract: [Figure not available: see fulltext.].
- Bardin, Vadim V.,Adonin, Nicolay Yu.
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p. 1523 - 1531
(2019/07/22)
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- Compounds for organic electroluminescent devices
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The present invention relates to boron compounds for use in electronic devices, especially organic electroluminescent devices, and to a process for preparing these compounds and to electronic devices, especially organic electroluminescent devices, comprising these compounds.
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Page/Page column 39
(2018/08/12)
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- Catalytic B-C Coupling by Si/B Exchange: A Versatile Route to π-Conjugated Organoborane Molecules, Oligomers, and Polymers
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Conjugated organoboranes have emerged as attractive hybrid materials for optoelectronic applications. Herein, a highly efficient, environmentally benign catalytic B-C bond formation method is presented that uses organosilicon compounds, dibromoboranes, and the metal-free organocatalyst Me3SiNTf2. This Si/B exchange approach has been successfully applied to the synthesis of arylborane molecules 4a-c, oligomers 8a,b, and polymers 8a′,b′. Photophysical investigations, supported by TD-DFT calculations, reveal highly effective π-conjugation in thienyl- and furylborane species; the latter are also highly emissive.
- Lik, Artur,Fritze, Lars,Müller, Lars,Helten, Holger
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supporting information
p. 5692 - 5695
(2017/05/04)
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- Synthesis of arylboronates by boron-induced ipso-deantimonation of triarylstibanes with boron trihalides and its application in one-pot two-step transmetallation/cross-coupling reactions
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The reaction of triarylstibanes (1) with boron trihalides (BCl3, and BBr3) afforded arylboron dihalides (2) by utilizing all the three aryl groups on the antimony. Boron intermediates (2) were transformed to arylboronates (3) in good to excellent yields by treatment with methanol and 1,3-propanediol. Further, the Pd-catalyzed reactions of 2 with organic halides such as 1-bromonaphthalene and benzoyl chloride in the presence of H2O afforded the corresponding cross-coupling products, unsymmetrical biaryls (4) and ketones (5), in moderate to good yields. The potential energy surfaces for the transmetallations of triarylstibanes (1) with BCl3 affording 2 were determined by molecular orbital calculations. The analyses of substituent effects on theoretically calculated reactivities showed the importance of the resonance effects of the ring substituents on these transmetallations.
- Yasuike, Shuji,Nakata, Kazuhide,Qin, Weiwei,Matsumura, Mio,Kakusawa, Naoki,Kurita, Jyoji
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- Access to ultra-high-molecular weight poly(ethylene) and activity boost in the presence of cyclopentene with group 4 bis-amido complexes
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ZrIV complexes of the type [Me2Si{(NR)(6-{2-(diethylboryl) phenyl} pyridyl-2-yl-N)}ZrCl2 thf] (R=tBu (4), adamantyl (7a); thf= tetrahydrofuran), [Me2Si{(NAd)(6-{2-(diphenylboryl)phenyl}pyridyl- 2-yl-N)}ZrCl2] (Ad=adamantyl (7b)), the
- Narayana, Gurram Venkata,Xu, Guangjuan,Wang, Dongren,Frey, Wolfgang,Buchmeiser, Michael R.
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p. 151 - 162
(2014/03/21)
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- Structural characteristics of dibromo-borylated benzene derivatives
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The crystal structures of five dibromobenzene derivatives, namely dibromoborylbenzene, C6H5BBr2, (I), 1-dibromoboryl-4-(trimethylsilyl)benzene, C9H13BBr 2Si, (II), 4-bromo-1-(dibromoboryl)
- Popp, Sebastian,Ruth, Kai,Lerner, Hans-Wolfram,Bolte, Michael
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experimental part
p. o226-o230
(2012/07/14)
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- Synthesis of a photoswitchable azobenzene-functionalized tris(indazol-1-yl) borate ligand and its ruthenium(II) cyclopentadienide complex
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In this paper, the design and synthesis of a new indazole bearing a photoisomerizable fragment at its 4-position are presented as well as the photoisomerization studies on both the indazole precursor and the final ruthenium model complex. It was obtained after five steps, the last one being the cleavage of the indazole protecting group. Reaction of 1 equiv of this functionalized indazole with 2 equiv of plain indazole and dibromophenylborane gave access to a mixture of four tripodal ligands of the tris(indazolyl)borate family. In a last step, complexation of this mixture with [RuCp(CH3CN)3]PF6 yielded the corresponding ruthenium complexes from which the target ruthenium complex coordinated to a dissymmetric azobenzene-functionalized tripodal ligand was successfully isolated. Photoisomerization occured reversibly upon irradiation with UV light at 365 nm.
- Jacquot de Rouville, Henri-Pierre,Villenave, Damien,Rapenne, Gwéna?l
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experimental part
p. 1885 - 1891
(2010/04/06)
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- Borylation of Arylsilanes, I. - A General, Easy, and Selective Access to Phenyldihaloboranes
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Upon treatment with trihaloboranes 2b-d the phenyltrimethylsilanes 1,6,8, and 10 yield the corresponding phenyldihaloboranes 3, 7, 9, and 11 with high selectivity.Benzylsilanes are not attacked.
- Kaufmann, Dieter
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p. 853 - 854
(2007/10/02)
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- Darstellung von Arylhalogenboranen
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In a ligand-exchange reaction between aryltrimethylsilanes, (ArSiMe3) and halogenboranes, (BX3 or ArBX2), arylhalogenboranes (ArBX2, ArAr'BX or Ar2BX) and halogentrimethylsilane are formed.This transfer of substituted aromatic groups from a silicon to a boron atom is an efficient synthetic pathway for the preparation of the corresponding arylhalogenboranes and diarylhalogenboranes with different aryl groups.Physical properties and spectroscopical data of the new arylhalogenboranes are given.
- Haubold, Wolfgang,Herdtle, Joerg,Gollinger, Walter,Einholz, Wolfgang
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- Contributions to the chemistry of boron. 121. Dicoordinate amidoboron cations
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Bromide abstraction from the amidoboron bromides (tmp)B(NR2)Br (R = CH3, C2H5; tmp = 2,2,6,6-tetramethylpiperidino) and (tmp)B(R)Br (R = CH3, C6H5) in methylene chloride produces tetrabromoaluminates of the dicoordinate diamidoboron cation (tmp=B=NR2)+ (5, 6) or the amido(organyl)boron cation (tmp=B-R)+ (7, 8). The constitution of these salts has been deduced by NMR spectroscopy (1H, 11B, 13C, 27Al), infrared spectroscopy, and electrical conductivity. In addition, the crystal structure of [tmp=B=N(CH3)2] AlBr4 reveals that the C2NBNC2 skeleton is of the allene type with a nearly linear NBN atomic arrangement (NBN angle 176°). Both BN distances are rather short (130 and 142 pm), demonstrating in addition to the IR data a fairly high bond order for the BN bonds in 5 and 6. The thermal stability of the salts decreases in the order 6 ≥ 5 > 7 > 8, and this is rationalized in terms of better charge delocalization in the diamido- vs. the monoamidoboron cations. This conclusion is substantiated by geometry-optimized MO calculations on model amidoboron cations.
- N?th, Heinrich,Staudigl, Rudolf,Wagner, Hans-Ulrich
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p. 706 - 716
(2008/10/08)
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- A New Borylation Method for Alkylbenzene and Polystyrene
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The borylation of alkylbenzenes by Hal2BH (Hal = F, Cl, Br) gives H2 and a mixture of m- and p-alkyl(dihaloboryl)benzenes.In the case of bulky alkyl groups, such as isopropyl, tert-butyl, these are partially split off as R - H and RBHal2.The phenyl groups in polystyrene-divinylbenzene copolymers undergo borylation with Br2BH in a 55percent yield.
- Paetzold, Peter,Hoffmann, Juergen
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p. 3724 - 3733
(2007/10/02)
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