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1.
Holger Hohmeister Peter Müller Isabel Usón Hans-Georg Schmidt Mathias Noltemeyer Jörg Magull 《Journal of fluorine chemistry》2003,120(1):59-64
The fluorination of [MeAlN(2,6-i-Pr2C6H3)]31 using 1 and 2 eq., respectively, trimethyltin fluoride leads to the mono- and difluoro compounds, [FAl(MeAl)2(N(2,6-i-Pr2C6H3))3]·2THF 2 and [(FAl)2MeAl(N(2,6-i-Pr2C6H3))3]·3THF 3, where each methyl group can be selectively exchanged for terminal fluorine atoms (AlF). The reaction of 1 and 3 eq. of trimethyltin fluoride leads to the trifluoro compound [FAlN(2,6-i-Pr2C6H3)]3·3THF 4 and [Me2SnN(2,6-i-Pr2C6H3)]25 as a by-product. The core of compound 5 consists of a tin-nitrogen four-membered Sn2N2 ring. 相似文献
2.
Bis(β‐diketiminato) lanthanide amides: synthesis,structure and catalysis for the polymerization of l‐lactide and ε‐caprolactone
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Yu Zheng Rui Jiao Xiao‐dong Shen Ming‐qiang Xue Ying‐ming Yao Yong Zhang Qi Shen 《应用有机金属化学》2014,28(6):461-470
Treatment of the chlorides (L2,6‐iPr2Ph)2LnCl (L2,6‐iPr2Ph = [(2,6‐iPr2C6H3)NC(Me)CHC(Me)N(C6H5)]?) with 1 equiv. of NaNH(2,6‐iPr2C6H3) afforded the monoamides (L2,6‐iPr2Ph)2LnNH(2,6‐iPr2C6H3) (Ln = Y ( 1 ), Yb ( 2 )) in good yields. Anhydrous LnCl3 reacted with 2 equiv. of NaL2,6‐iPr2Ph in THF, followed by treatment with 1 equiv. of NaNH(2,6‐iPr2C6H3), giving the analogues (L2,6‐iPr2Ph)2LnNH(2,6‐iPr2C6H3) (Ln = Sm ( 3 ), Nd ( 4 )). Two monoamido complexes stabilized by two L2‐Me ligands, (L2‐Me)2LnNH(2,6‐iPr2C6H3) (L2‐Me = [N(2‐MeC6H4)C(Me)]2CH)?; Ln = Y ( 5 ), Yb ( 6 )), were also synthesized by the latter route. Complexes 1 , 2 , 3 , 4 , 5 , 6 were fully characterized, including X‐ray crystal structure analyses. Complexes 1 , 2 , 3 , 4 , 5 , 6 are isostructural. The central metal in each complex is ligated by two β‐diketiminato ligands and one amido group in a distorted trigonal bipyramid. All the complexes were found to be highly active in the ring‐opening polymerization of L‐lactide (L‐LA) and ε‐caprolactone (ε‐CL) to give polymers with relatively narrow molar mass distributions. The activity depends on both the central metal and the ligand (Yb < Y < Sm ≈ Nd and L2‐Me < L2,6‐iPr2Ph). Remarkably, the binary 3/benzyl alcohol (BnOH) system exhibited a striking ‘immortal’ nature and proved able to quantitatively convert 5000 equiv. of L‐LA with up to 100 equiv. of BnOH per metal initiator. All the resulting PLAs showed monomodal, narrow distributions (Mw/Mn = 1.06 ? 1.08), with molar mass (Mn) decreasing proportionally with an increasing amount of BnOH. The binary 4/BnOH system also exhibited an ‘immortal’ nature in the polymerization of ε‐CL in toluene. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
3.
V. Yu. Rad’kov A. V. Cherkasov T. A. Kovylina A. A. Trifonov 《Russian Chemical Bulletin》2016,65(12):2805-2811
A reaction of anhydrous yttrium chloride with an equimolar amount of lithium amidinateamidopyridinate obtained in situ by metallation of N,N’-bis(2,6-dimethylphenyl)-N-{6-[(2,6-dimethylphenyl)amino]pyridin-2-yl}acetimidamide ((2,6-Me2C6H3)NH(2,6-C6H3N)N(2,6-Me2C6H3)C(Me)=N(2,6-Me2C6H3), L1H) (1) with n-butyllithium in THF at–70 °C was used to synthesize the yttrium dichloride complex (L1)YCl2(THF)2 (2). The lutetium bis(alkyl) complex, namely, N’-(2,6-diisopropylphenyl)-N-(2,6-dimethylphenyl-N-{6-[(2,6-dimethylphenyl)amido]pyridin-2-yl}acetimidoamidinatebis(trimethylsilylmethyl)lutetium (4), was obtained by the reaction of N’-(2,6-diisopropylphenyl)-N-(2,6-dimethylphenyl)-N-(6-((2,6dimethylphenyl)amino)pyridin-2-yl)acetimidamide ((2,6-Me2C6H3)NH(2,6-C6H3N)N-(2,6-Me2C6H3)C(Me)=N(2,6-Pr 2 i C6H3), L2H (3)) with an equimolar amount of Lu(CH2SiMe3)3(THF)2. Complex 4 was found to be very stable and did not show indications of C—H-activation and other kinds of disintegration in benzene or toluene solution even upon prolonged heating at 60 °C. The reaction of complex 4 with an equimolar amount of 2,6-diisopropylaniline in toluene solution at room temperature led to the formation of the lutetium alkyl-anilide complex (L2)Lu(CH2SiMe3)(NH-2,6-Pr 2 i C6H3) (5). A three-component system 4—AlBu 3 i —[X][B(C6F5)4] ([X] = [Ph3C], [PhNHMe2], the molar ratio of 1: 10: 1) was found to catalyze polymerization of isoprene. 相似文献
4.
《Journal of polymer science. Part A, Polymer chemistry》2018,56(8):922-930
A family of unsymmetrical 1,2‐bis(imino)acenaphthene‐palladium methyl chloride complexes [1‐[2,6‐{(C6H5)2CH}2‐ 4‐{C(CH3)3}‐C6H2N]‐2‐(ArN)C2C10H6]PdMeCl (Ar = 2,6‐Me2Ph Pd1 , 2,6‐Et2Ph Pd2 , 2,6‐iPr2Ph Pd3 , 2,4,6‐Me3Ph Pd4 , 2,6‐Et2‐4‐MePh Pd5 ) have been prepared and fully characterized by 1H/13C NMR, FTIR spectroscopies, and elemental analysis. X‐ray diffraction analysis of Pd2 complex revealed a square planar geometry. Upon activation with methylaluminoxane, all the palladium complexes displayed high activities for norbornene (NBE) homo‐polymerization producing insoluble polymer. For the copolymerization of NBE with ethylene, Pd4 complex exhibited good activities with high incorporation of ethylene (up to 59.2–77.4%) and the resultant copolymer showed high molecular weights as maximum as 150.5 kg mol−1. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 922–930 相似文献
5.
Randi Zhang Yanping Ma Mingyang Han Gregory A. Solan Yaqing Pi Yang Sun Wen‐Hua Sun 《应用有机金属化学》2019,33(10)
The bis(arylimino)pyridines, 2‐[CMeN{2,6‐{(4‐FC6H4)2CH}2–4‐NO2}]‐6‐(CMeNAr)C5H3N (Ar = 2,6‐Me2C6H3 L1 , 2,6‐Et2C6H3 L2 , 2,6‐i‐Pr2C6H3 L3 , 2,4,6‐Me3C6H2 L4 , 2,6‐Et2–4‐MeC6H2 L5 ), each containing one N′‐2,6‐bis{di(4‐fluorophenyl)methyl}‐4‐nitrophenyl group, have been synthesized by two successive condensation reactions from 2,6‐diacetylpyridine. Their subsequent treatment with anhydrous cobalt (II) chloride gave the corresponding N,N,N′‐CoCl2 chelates, Co1 – Co5 , in excellent yield. All five complexes have been characterized by 1H/19F NMR and IR spectroscopy as well as by elemental analysis. In addition, the molecular structures of Co1 and Co3 have been determined and help to emphasize the differences in steric properties imposed by the inequivalent N‐aryl groups; distorted square pyramidal geometries are adopted by each complex. Upon activation with either methylaluminoxane (MAO) or modified methylaluminoxane (MMAO), precatalyts Co1 – Co5 collectively exhibited very high activities for ethylene polymerization with 2,6‐dimethyl‐substituted Co1 the most active (up to 1.1 × 107 g (PE) mol?1 (Co) h?1); the MAO systems were generally more productive. Linear polyethylenes of exceptionally high molecular weight (Mw up to 1.3 × 106 g mol?1) were obtained in all cases with the range in dispersities exhibited using MAO as co‐catalyst noticeably narrower than with MMAO [Mw/Mn: 3.55–4.77 ( Co1 – Co5 /MAO) vs. 2.85–12.85 ( Co1 – Co5 /MMAO)]. Significantly, the molecular weights of the polymers generated using this class of cobalt catalyst are higher than any literature values reported to date using related N,N,N‐bis (arylimino)pyridine‐cobalt catalysts. 相似文献
6.
《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2017,129(48):15629-15633
Herein we report the employment of the quintuply bonded dichromium amidinates [Cr{κ2‐HC(N‐2,6‐iPr2C6H3)(N‐2,6‐R2C6H3)}]2 (R=iPr ( 1 ), Me ( 7 )) as catalysts to mediate the [2+2+2] cyclotrimerization of terminal alkynes giving 1,3,5‐trisubstituted benzenes. During the catalysis, the ultrashort Cr−Cr quintuple bond underwent reversible cleavage/formation, corroborated by the characterization of two inverted arene sandwich dichromium complexes (μ‐η6:η6‐1,3,5‐(Me3Si)3C6H3)[Cr{κ2‐HC(N ‐2,6‐iPr2C6H3)(N ‐2,6‐R2C6H3)}]2 (R=iPr ( 5 ), Me ( 8 )). In the presence of σ donors, such as THF and 2,4,6‐Me3C6H2CN, the bridging arene 1,3,5‐(Me3Si)3C6H3 in 5 and 8 was extruded and 1 and 7 were regenerated. Theoretical calculations were employed to disclose the reaction pathways of these highly regioselective [2+2+2] cylcotrimerization reactions of terminal alkynes. 相似文献
7.
Muhammad Zada Liwei Guo Randi Zhang Wenjuan Zhang Yanping Ma Gregory A. Solan Yang Sun Wen‐Hua Sun 《应用有机金属化学》2019,33(5)
Five examples of unsymmetrical 1,2‐bis (arylimino) acenaphthene ( L1 – L5 ), each containing one N‐2,4‐bis (dibenzocycloheptyl)‐6‐methylphenyl group and one sterically and electronically variable N‐aryl group, have been used to prepare the N,N′‐nickel (II) halide complexes, [1‐[2,4‐{(C15H13}2–6‐MeC6H2N]‐2‐(ArN)C2C10H6]NiX2 (X = Br: Ar = 2,6‐Me2C6H3 Ni1 , 2,6‐Et2C6H3 Ni2 , 2,6‐i‐Pr2C6H3 Ni3 , 2,4,6‐Me3C6H2 Ni4 , 2,6‐Et2–4‐MeC6H2 Ni5 ) and (X = Cl: Ar = 2,6‐Me2C6H3 Ni6 , 2,6‐Et2C6H3 Ni7 , 2,6‐i‐Pr2C6H3 Ni8 , 2,4,6‐Me3C6H2 Ni9 , 2,6‐Et2–4‐MeC6H2 Ni10 ), in high yield. The molecular structures Ni3 and Ni7 highlight the extensive steric protection imparted by the ortho‐dibenzocycloheptyl group and the distorted tetrahedral geometry conferred to the nickel center. On activation with either Et2AlCl or MAO, Ni1 – Ni10 exhibited very high activities for ethylene polymerization with the least bulky Ni1 the most active (up to 1.06 × 107 g PE mol?1(Ni) h?1 with MAO). Notably, these sterically bulky catalysts have a propensity towards generating very high molecular weight polyethylene with moderate levels of branching and narrow dispersities with the most hindered Ni3 and Ni8 affording ultra‐high molecular weight material (up to 1.5 × 106 g mol?1). Indeed, both the activity and molecular weights of the resulting polyethylene are among the highest to be reported for this class of unsymmetrical 1,2‐bis (imino)acenaphthene‐nickel catalyst. 相似文献
8.
The sterically demanding pyridines 2,6-Ar2C6H3N [Ar = 2,4,6-Me3C6H2 (1) or 2,4,6-Pri3C6H2 (2)] were prepared by a palladium catalysed Kumada C–C coupling reaction in high yield. Pyridine 1 reacted with one equivalent of GaCl3 to afford the tetra-chloro gallate–pyridinium ion pair complex [GaCl4]−[2,6-(2,4,6-Me3C6H2)2C6H3NH]+ (3). Contrastingly, pyridine 2 reacted with one equivalent of GaCl3 to afford the anticipated donor-acceptor complex [GaCl3{2,6-(2,4,6-Pri3C6H2)2C6H3N}] (4). Complexes 1–4 have been characterised variously by single crystal X-ray diffraction, NMR, CHN, and mass spectrometry. 相似文献
9.
D. N. Akbayeva 《Russian Journal of Coordination Chemistry》2006,32(5):329-334
New complexes of Cu(I) and Ru(II) with elemental (white) phosphorus (P4), [Cu(C5H-i-Pr4)(η2-P4)], [Cu(C5H-i-Pr4)(μ,η2:1-P4)Cu(C5H-i-Pr4)], and [Ru(C5Me5)(PCy3)(η2-P4)Cl], are synthesized with tetraphosphorus molecule as bidentate η2-ligand. The complexes are obtained by reacting elemental phosphorus with the Cu carbonyl(tetraisopropylcyclopentadienyl) complex [Cu(C5H-i-Pr4)(CO)] or with Ru(II) (pentamethylcyclopentadienyl)(tricyclohexylphosphine) chloride, [Ru(C5Me5)(PCy3)Cl]. The structures and compositions of the obtained complexes are studied by 1H, 31P NMR method and elemental analysis. The P4 molecule is connected to Cu(I) and Ru(II) fragments through the P-P edge due to a side coordination. 相似文献
10.
Alexander C. Filippou Prof. Dr. Oleg Chernov Dipl.‐Chem. Burgert Blom Kai W. Stumpf Dipl.‐Chem. Gregor Schnakenburg Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(9):2866-2872
The first N‐heterocyclic carbene adducts of arylchlorosilylenes are reported and compared with the homologous germanium compounds. The arylsilicon(II) chlorides SiArCl(Im‐Me4) [Ar=C6H3‐2,6‐Mes2 (Mes=C6H2‐2,4,6‐Me3), C6H3‐2,6‐Trip2 (Trip=C6H2‐2,4,6‐iPr3)] were obtained selectively on dehydrochlorination of the arylchlorosilanes SiArHCl2 with 1,3,4,5‐tetramethylimidazol‐2‐ylidene (Im‐Me4). The analogous arylgermanium(II) chlorides GeArCl(Im‐Me4) were prepared by metathetical exchange of GeCl2(Im‐Me4) with LiC6H3‐2,6‐Mes2 or addition of Im‐Me4 to GeCl(C6H3‐2,6‐Trip2). All compounds were fully characterized. Density functional calculations on ECl(C6H3‐2,6‐Trip2)(Im‐Me4), where E=Si, Ge, at different levels of theory show very good agreement between calculated and experimental bonding parameters, and NBO analyses reveal similar electronic structures of the two aryltetrel(II) chlorides. The low gas‐phase Gibbs free energy of bond dissociation of SiCl(C6H3‐2,6‐Trip2)(Im‐Me4) (Δ${G{{{\circ}\hfill \atop {\rm calcd}\hfill}}}$ =28.1 kJ mol?1) suggests that the carbene adducts SiArCl(Im‐Me4) may be valuable transfer reagents of the arylsilicon(II) chlorides SiArCl. 相似文献
11.
Qiuyue Zhang Yanping Ma Hongyi Suo Gregory A. Solan Tongling Liang Wen‐Hua Sun 《应用有机金属化学》2019,33(10)
The unsymmetrical bis (arylimino)pyridines, 2‐[CMeN{2,6‐{(4‐FC6H4)2CH}2–4‐t‐BuC6H2}]‐6‐(CMeNAr)C5H3N (Ar = 2,6‐Me2C6H3 L1 , 2,6‐Et2C6H3 L2 , 2,6‐i‐Pr2C6H3 L3 , 2,4,6‐Me3C6H2 L4 , 2,6‐Et2–4‐MeC6H2 L5 ), each containing one N‐aryl group bedecked with ortho‐substituted fluorobenzhydryl groups, have been employed in the preparation of the corresponding five‐coordinate cobalt (II) chelates, LCoCl2 ( Co1 – Co5 ); the symmetrical comparator [2,6‐{CMeN(2,6‐(4‐FC6H4)2CH)2–4‐t‐BuC6H2}2C5H3N]CoCl2 (Co6) is also reported. All cobaltous complexes are paramagnetic and have been characterized by 1H/19F NMR spectroscopy, FT‐IR spectroscopy and elemental analysis. The molecular structures of Co3 and Co6 highlight the different degrees of steric protection given to the metal center by the particular N‐aryl group combination. Depending on the aluminoxane co‐catalyst employed to activate the cobalt precatalyst, distinct variations in thermal stability and activity of the catalyst towards ethylene polymerization were exhibited. In particular with MAO, the resultant catalysts reached their optimal performance at 70 °C delivering high activities of up to 10.1 × 106 g PE (mol of Co)?1 h?1 with Co1 > Co4 > Co2 > Co5 > Co3 >> Co6 . On the other hand, using MMAO, the catalysts operate most effectively at 30 °C but are by comparison less productive. In general, the polyethylenes were highly linear, narrowly disperse and displayed a wide range of molecular weights [Mw range: 18.5–58.7 kg mol?1 (MAO); 206.1–352.5 kg mol?1 (MMAO)]. 相似文献
12.
Tomáš Řezníček Libor Dostál Aleš Růžička Jiří Kulhánek Filip Bureš Roman Jambor 《应用有机金属化学》2011,25(3):173-179
The phosphines L1PPh2 (1) and L2PPh2 (2) containing different Y,C,Y‐chelating ligands, L1 = 2,6‐(tBuOCH2)2C6H3? and L2 = 2,6‐(Me2NCH2)2C6H3?, were treated with PdCl2 and di‐µ‐chloro‐bis[2‐[(N,N‐dimethylamino)methyl]phenyl‐C,N]‐dipalladium(II) and yielded complexes trans‐{[2,6‐(tBuOCH2)2C6H3]PPh2}2PdCl2 (3), {[2,6‐(Me2NCH2)2C6H3]PPh2} PdCl2 (4), {[2,6‐(tBuOCH2)2C6H3]PPh2}Pd(Cl)[2‐(Me2NCH2)C6H4] (5) and {[2,6‐(Me2NCH2)2C6H3]PPh2}Pd(Cl)[2‐(Me2NCH2)C6H4] (6) as the result of different ability of starting phosphines 1 and 2 to complex PdCl2. Compounds 3–6 were characterized by 1H, 13C, 31P NMR spectroscopy and ESI‐MS. The molecular structures of 3,4 and 6 were also determined by X‐ray diffraction analysis. The catalytic activity of complexes 3–6 was evaluated in the Suzuki‐Miyaura cross‐coupling reaction. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
13.
Herbert Schumann Jrn Winterfeld Esther C. E. Rosenthal Holger Hemling Lothar Esser 《无机化学与普通化学杂志》1995,621(1):122-130
Organometallic Compounds of the Lanthanides. 88. Monomeric Lanthanide(III) Amides: Synthesis and X-Ray Crystal Structure of [Nd{N(C6H5)(SiMe3)}3(THF)], [Li(THF)2(μ-Cl)2Nd{N(C6H3Me2-2,6)(SiMe3)}2(THF)], and [ClNd{N(C6H3-iso-Pr2-2,6)(SiMe3)} 2(THF)] A series of lanthanide(III) amides [Ln{N(C6H5) · (SiMe3)}3(THF)x] [Ln = Y ( 1 ), La ( 2 ), Nd ( 3 ), Sm ( 4 ), Eu ( 5 ), Tb ( 6 ), Er ( 8 ), Yb ( 9 ), Lu ( 10 )] could be prepared by the reaction of lanthanide trichlorides, LnCl3, with LiN(C6H5)(SiMe3). Treatment of NdCl3(THF)2 and LuCl3(THF)3 with the lithium salts of the bulky amides [N(C6H3R2-2,6)(SiMe3)]? (R = Me, iso-Pr) results in the formation of the lanthanide diamides [Li(THF)2(μ-Cl)2Nd{N(C6H3Me2-2, 6)(SiMe3)}2(THF)] ( 11 ) and [ClLn{N(C6H3-iso-Pr2-2,6)(SiMe3)} 2(THF)] [Ln = Nd ( 12 ), Lu ( 13 )], respectively. The 1H- and 13C-NMR and mass spectra of the new compounds as well as the X-ray crystal structures of the neodymium derivatives 3 , 11 and 12 are discussed. 相似文献
14.
Zhongbao Jian Prof. Dr. Dongmei Cui Prof. Dr. Zhaomin Hou 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(9):2674-2684
A series of rare‐earth‐metal–hydrocarbyl complexes bearing N‐type functionalized cyclopentadienyl (Cp) and fluorenyl (Flu) ligands were facilely synthesized. Treatment of [Y(CH2SiMe3)3(thf)2] with equimolar amount of the electron‐donating aminophenyl‐Cp ligand C5Me4H‐C6H4‐o‐NMe2 afforded the corresponding binuclear monoalkyl complex [({C5Me4‐C6H4‐o‐NMe(μ‐CH2)}Y{CH2SiMe3})2] ( 1 a ) via alkyl abstraction and C? H activation of the NMe2 group. The lutetium bis(allyl) complex [(C5Me4‐C6H4‐o‐NMe2)Lu(η3‐C3H5)2] ( 2 b ), which contained an electron‐donating aminophenyl‐Cp ligand, was isolated from the sequential metathesis reactions of LuCl3 with (C5Me4‐C6H4‐o‐NMe2)Li (1 equiv) and C3H5MgCl (2 equiv). Following a similar procedure, the yttrium‐ and scandium–bis(allyl) complexes, [(C5Me4‐C5H4N)Ln(η3‐C3H5)2] (Ln=Y ( 3 a ), Sc ( 3 b )), which also contained electron‐withdrawing pyridyl‐Cp ligands, were also obtained selectively. Deprotonation of the bulky pyridyl‐Flu ligand (C13H9‐C5H4N) by [Ln(CH2SiMe3)3(thf)2] generated the rare‐earth‐metal–dialkyl complexes, [(η3‐C13H8‐C5H4N)Ln(CH2SiMe3)2(thf)] (Ln=Y ( 4 a ), Sc ( 4 b ), Lu ( 4 c )), in which an unusual asymmetric η3‐allyl bonding mode of Flu moiety was observed. Switching to the bidentate yttrium–trisalkyl complex [Y(CH2C6H4‐o‐NMe2)3], the same reaction conditions afforded the corresponding yttrium bis(aminobenzyl) complex [(η3‐C13H8‐C5H4N)Y(CH2C6H4‐o‐NMe2)2] ( 5 ). Complexes 1 – 5 were fully characterized by 1H and 13C NMR and X‐ray spectroscopy, and by elemental analysis. In the presence of both [Ph3C][B(C6F5)4] and AliBu3, the electron‐donating aminophenyl‐Cp‐based complexes 1 and 2 did not show any activity towards styrene polymerization. In striking contrast, upon activation with [Ph3C][B(C6F5)4] only, the electron‐withdrawing pyridyl‐Cp‐based complexes 3 , in particular scandium complex 3 b , exhibited outstanding activitiy to give perfectly syndiotactic (rrrr >99 %) polystyrene, whereas their bulky pyridyl‐Flu analogues ( 4 and 5 ) in combination with [Ph3C][B(C6F5)4] and AliBu3 displayed much‐lower activity to afford syndiotactic‐enriched polystyrene. 相似文献
15.
Tunable Fluorophores Based on 2‐(N‐Arylimino)pyrrolyl Chelates of Diphenylboron: Synthesis,Structure, Photophysical Characterization,and Application in OLEDs
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Dr. D. Suresh Patrícia S. Lopes Bruno Ferreira Cláudia A. Figueira Dr. Clara S. B. Gomes Dr. Pedro T. Gomes Dr. Roberto E. Di Paolo Prof. António L. Maçanita Dr. M. Teresa Duarte Dr. Ana Charas Dr. Jorge Morgado Prof. Maria José Calhorda 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(14):4126-4140
Reactions of 2‐(N‐arylimino)pyrroles (HNC4H3C(H)?N‐Ar) with triphenylboron (BPh3) in boiling toluene afford the respective highly emissive N,N′‐boron chelate complexes, [BPh2{κ2N,N′‐NC4H3C(H)?N‐Ar}] (Ar=C6H5 ( 12 ), 2,6‐Me2‐C6H3 ( 13 ), 2,6‐iPr2‐C6H3 ( 14 ), 4‐OMe‐C6H4 ( 15 ), 3,4‐Me2‐C6H3 ( 16 ), 4‐F‐C6H4 ( 17 ), 4‐NO2‐C6H4 ( 18 ), 4‐CN‐C6H4 ( 19 ), 3,4,5‐F3‐C6H2 ( 20 ), and C6F5 ( 21 )) in moderate to high yields. The photophysical properties of these new boron complexes largely depend on the substituents present on the aryl rings of their N‐arylimino moieties. The complexes bearing electron‐withdrawing aniline substituents 17 – 20 show more intense (e.g., ?f=0.71 for Ar=4‐CN‐C6H4 ( 19 ) in THF), higher‐energy (blue) fluorescent emission compared to those bearing electron‐donating substituents, for which the emission is redshifted at the expense of lower quantum yields (?f=0.13 and 0.14 for Ar=4‐OMe‐C6H4 ( 15 ) and 3,4‐Me2‐C6H3 ( 16 ), respectively, in THF). The presence of substituents bulkier than a hydrogen atom at the 2,6‐positions of the aryl groups strongly restricts rotation of this moiety towards coplanarity with the iminopyrrolyl ligand framework, inducing a shift in the emission to the violet region (λmax=410–465 nm) and a significant decrease in quantum yield (?f=0.005, 0.023, and 0.20 for Ar=2,6‐Me2‐C6H3 ( 13 ), 2,6‐iPr2‐C6H3 ( 14 ), and C6F5 ( 21 ), respectively, in THF), even when electron‐withdrawing groups are also present. Density functional theory (DFT) and time‐dependent DFT (TD‐DFT) calculations have indicated that the excited singlet state has a planar aryliminopyrrolyl ligand, except when prevented by steric hindrance (ortho substituents). Calculated absorption maxima reproduce the experimental values, but the error is higher for the emission wavelengths. Organic light‐emitting diodes (OLEDs) have been fabricated with the new boron complexes, with luminances of the order of 3000 cd m?2 being achieved for a green‐emitting device. 相似文献
16.
Dapeng Zhao Dr. Wei Gao Dr. Ying Mu Prof. Ling Ye 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(14):4394-4401
A series of new titanium(IV) complexes with o‐metalated arylimine and/or cis‐9,10‐dihydrophenanthrenediamide ligands, [o‐C6H4(CH?NR)TiCl3] (R=2,6‐iPr2C6H3 ( 3 a ), 2,6‐Me2C6H3 ( 3 b ), tBu ( 3 c )), [cis‐9,10‐PhenH2(NR)2TiCl2] (PhenH2=9,10‐dihydrophenanthrene; R=2,6‐iPr2C6H3 ( 4 a ), 2,6‐Me2C6H3 ( 4 b ), tBu ( 4 c )), [{cis‐9,10‐PhenH2(NR)2}{o‐C6H4(HC?NR)}TiCl] (R=2,6‐iPr2C6H3 ( 5 a ), 2,6‐Me2C6H3 ( 5 b ), tBu ( 5 c )), have been synthesised from the reactions of TiCl4 with o‐C6H4(CH?NR)Li (R=2,6‐iPr2C6H3, 2,6‐Me2C6H3, tBu). Complexes 4 and 5 were formed unexpectedly from the reactions of TiCl4 with two or three equivalents of the corresponding o‐C6H4(CH?NR)Li followed by sequential intramolecular C? C bond‐forming reductive elimination and oxidative coupling reactions. Attempts to isolate the intermediates, [{o‐C6H4(CH?NR)}2TiCl2] ( 2 ), were unsuccessful. All complexes were characterised by 1H and 13C NMR spectroscopy, and the molecular structures of 3 a , 4 a – c , 5 a , and 5 c were determined by X‐ray crystallography. 相似文献
17.
From Dibismuthenes to Three‐ and Two‐Coordinated Bismuthinidenes by Fine Ligand Tuning: Evidence for Aromatic BiC3N Rings through a Combined Experimental and Theoretical Study
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Iva Vránová Dr. Mercedes Alonso Dr. Rabindranath Lo Dr. Robert Sedlák Dr. Roman Jambor Prof. Aleš Růžička Prof. Frank De Proft Prof. Pavel Hobza Dr. Libor Dostál 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(47):16917-16928
The reduction of N,C,N‐chelated bismuth chlorides [C6H3‐2,6‐(CH?NR)2]BiCl2 [where R=tBu ( 1 ), 2′,6′‐Me2C6H3 ( 2 ), or 4′‐Me2NC6H4 ( 3 )] or N,C‐chelated analogues [C6H2‐2‐(CH?N‐2′,6′‐iPr2C6H3)‐4,6‐(tBu)2]BiCl2 ( 4 ) and [C6H2‐2‐(CH2NEt2)‐4,6‐(tBu)2]BiCl2 ( 5 ) is reported. Reduction of compounds 1 – 3 gave monomeric N,C,N‐chelated bismuthinidenes [C6H3‐2,6‐(CH?NR)2]Bi [where R=tBu ( 6 ), 2′,6′‐Me2C6H3 ( 7 ) or 4′‐Me2NC6H4 ( 8 )]. Similarly, the reduction of 4 led to the isolation of the compound [C6H2‐2‐(CH?N‐2′,6′‐iPr2C6H3)‐4,6‐(tBu)2]Bi ( 9 ) as an unprecedented two‐coordinated bismuthinidene that has been structurally characterized. In contrast, the dibismuthene {[C6H2‐2‐(CH2NEt2)‐4,6‐(tBu)2]Bi}2 ( 10 ) was obtained by the reduction of 5 . Compounds 6 – 10 were characterized by using 1H and 13C NMR spectroscopy and their structures, except for 7 , were determined with the help of single‐crystal X‐ray diffraction analysis. It is clear that the structure of the reduced products (bismuthinidene versus dibismuthene) is ligand‐dependent and particularly influenced by the strength of the N→Bi intramolecular interaction(s). Therefore, a theoretical survey describing the bonding situation in the studied compounds and related bismuth(I) systems is included. Importantly, we found that the C3NBi chelating ring in the two‐coordinated bismuthinidene 9 exhibits significant aromatic character by delocalization of the bismuth lone pair. 相似文献
18.
《Journal of Coordination Chemistry》2012,65(20):3718-3726
We report the synthesis and structural determination of three uranium(IV) complexes bearing two, four, and six salicylaldiminate ligands. Reaction of UI4(1,4-dioxane)2 with two, four, and six equivalents of K[OC6H4C(H)=N(2,6-iPr2C6H3)], 1, yielded [(2,6-iPr2C6H3)N=C(H)C6H4O-κ2(O,N)]2UI2(NCCH3), 2, [(2,6-iPr2C6H3)N=C(H)C6H4O-κ1(O)]2[(2,6-iPr2C6H3)N=C(H)C6H4O-κ2(O,N)]2U(THF), 3, and {[2,6-iPr2C6H3)N=C(H)C6H4O-κ1(O)]6U}2?, 4. While 2 shows normal κ2-coordination through both oxygen and nitrogen donors, 3 has two salicylaldiminate ligands bound only through oxygen and 4 has all six ligands bound only through oxygen. This is an exceedingly rare example of a chelating ligand not completing its chelation in f-element chemistry. In addition, 4 is the first report of a homoleptic octahedral actinide complex with a Schiff base ligand. 相似文献
19.
Hsueh‐Ju Liu Micah S. Ziegler T. Don Tilley 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(22):6722-6726
Reactivity studies of the thermally stable ruthenostannylene complex [Cp*(IXy)(H)2Ru Sn Trip] ( 1 ; IXy=1,3‐bis(2,6‐dimethylphenyl)imidazol‐2‐ylidene; Cp*=η5‐C5Me5; Trip=2,4,6‐iPr3C6H2) with a variety of organic substrates are described. Complex 1 reacts with benzoin and an α,β‐unsaturated ketone to undergo [1+4] cycloaddition reactions and afford [Cp*(IXy)(H)2RuSn(κ2‐O,O‐OCPhCPhO)Trip] ( 2 ) and [Cp*(IXy)(H)2RuSn(κ2‐O,C‐OCPhCHCHPh)Trip] ( 3 ), respectively. The reaction of 1 with ethyl diazoacetate resulted in a tin‐substituted ketene complex [Cp*(IXy)(H)2RuSn(OC2H5)(CHCO)Trip] ( 4 ), which is most likely a decomposition product from the putative ruthenium‐substituted stannene complex. The isolation of a ruthenium‐substituted stannene [Cp*(IXy)(H)2RuSn(Flu)Trip] ( 5 ) and stanna‐imine [Cp*(IXy)(H)2RuSn(κ2‐N,O‐NSO2C6H4Me)Trip] ( 6 ) complexes was achieved by treatment of 1 with 9‐diazofluorene and tosyl azide, respectively. 相似文献
20.
The reaction involving N‐aryliminopyrrolyl ligand, 2‐((p‐Me‐C6H3N=CMe)–C4H3NH) ( 1a ) (ImpMe‐H), and Zr(OtBu)4 in a 2:1 molar ratio in toluene at 90 °C afforded the corresponding bis(iminopyrrolyl) complex of zirconium, [(ImpMe)2Zr(OtBu)2] ( 2a ) having two bidentate iminopyrrole groups in the coordination sphere. In contrast, the bulkier 2‐((2,6‐iPr2C6H3N=CH)–C4H3NH) ( 1b ) (ImpDipp‐H) and Zr(OtBu)4 in a 1:1 molar ratio under the same condition yielded the corresponding mono(iminopyrrolyl) complex of zirconium, [(ImpDipp)Zr(OtBu)3(THF)] ( 2b ), which contains only one bidentate iminopyrrole moiety in the coordination sphere. Both complexes were characterized by single‐crystal X‐ray diffraction analysis. The solid‐state structures reveal that the bulky iminopyrrole ligands cause a steric crowding around the zirconium ion along with three tert‐butoxide ligands attached to the central metal atom. 相似文献