210882-44-3Relevant academic research and scientific papers
Aluminum Complexes Bearing N-Protected 2-Amino- or 2-Imino-Functionalized Pyrrolyl Ligands: Synthesis, Structure, and Catalysis for Preparation of Pyrrolyl-End-Functionalized Polyesters
Wei, Yun,Wang, Shaowu,Zhu, Xiancui,Zhou, Shuangliu,Mu, Xiaolong,Huang, Zeming,Hong, Dongjing
, p. 2621 - 2629 (2016)
Reactivity of N-protected 2-amino- or 2-imino-functionalized pyrroles with aluminum alkyls was investigated, resulting in the isolation of a series of aluminum alkyl complexes. Treatment of 2-imino-functionalized pyrrole with AlMe3 produced only imino-coordinated aluminum complex 1-Bn-2-(2,6-iPr2C6H3N=CH)C4H3NAlMe3 (1), while reactions of N-protected 2-amino-functionalized pyrroles with aluminum alkyls produced the aluminum alkyl complexes {[η1-μ- η1:η1-1-R1-2-(2,6-iPr2C6H3NCH2)C4H2N]AlR}2 (R1 = Bn, R = Me (2); R1 = Bn, R = Et (3); R1 = R = Me (4); R1 = Me, R = Et (5)), bearing 3-carbon bonded pyrrolyl ligands via C-H σ-bond metathesis reaction. Further reactions of complexes 2-5 with a stoichiometric amount of isopropyl alcohol (iPrOH) afforded the corresponding aluminum alkoxide complexes [1-R1-2-(2,6-iPr2C6H3NCH2)C4H3NAlR(μ-OiPr)]2 (R1 = Bn, R = Me (6); R1 = Bn, R = Et (7); R1 = R = Me (8); R1 = Me, R = Et (9)) through selective cleavage of the Al-C (Pyr) bonds. The solid-state structures of the aluminum complexes 1-6 and 8 were confirmed by an X-ray diffraction study. These aluminum alkyl complexes exhibited notable activity toward the ring-opening polymerization of ?-caprolactone and l-lactide in the absence of alcohol. The end group analysis of the ?-CL oligomer gave strong support that the polymerization proceeded via a coordination-insertion mechanism involving a unique Al-C (Pyr) bond initiation, providing pyrrolyl-end-functionalized polyesters.
Regioselective Mannich bases of pyrrole-2-carbaldehyde and binuclear copper(II) complexes of bis(iminopyrrolyl) ligand containing the piperazine ring
Kumar, Rajnish,Paul, Tapas,Jana, Oishi,Mani, Ganesan
, p. 70 - 78 (2016)
Iminopyrrolyl ligands have attracted an attention in the field of coordination chemistry. As every iminopyrrolyl ligand contains at least one acidic pyrrole NH group, it often forms an anionic five-membered chelate ring with a metal. Unlike the familiar pincer framework ligand systems, iminopyrrolyl coordination chemistry is in a developing stage. Hence, we set the synthesis of bis(iminopyrrole) framework ligand containing the piperazine ring as a spacer unit between two mono(iminopyrrolyl) moieties. The Mannich reaction of pyrrole-2-carbaldehyde with piperazine and formaldehyde afforded two new dialdehydes: N,N′-bis(5-formylpyrrol-1-ylmethyl)piperazine 1 and N,N′-bis(5-formylpyrrol-2-ylmethyl)piperazine, 2, which are regioselective products formed in good yields. The pyrrole N aminomethylated dialdehyde 1 was isolated in the absence of an added acid. Conversely, the pyrrole α-C aminomethylated dialdehyde compound 2 was obtained in the presence of a mineral acid. They have different spectroscopic and physical properties. Even they offered different Schiff bases under the same reaction conditions. The Schiff base condensation reaction of 2 with 2,6-diisopropylanilline in the presence of HNO3 gave the expected [1+2] Schiff base in 53% yield after column separation. Conversely, the other dialdehyde 1 yielded the piperazinylmethyl C-N bonds hydrolyzed known 2-iminopyrrole compound. Further, the treatment of the structurally characterized [1+2] bis(iminopyrrolyl) ligand with copper(II) carboxylates [Cu(OOCR)2(H2O)] (R = H, Me and Ph) gave three different binuclear five-coordinate copper(II) complexes. Their structures were determined by single crystal X-ray diffraction studies. Interestingly, the piperazine ring nitrogens are not coordinated, rather involved in intramolecular hydrogen bonding interactions with the coordinated solvent molecules at the copper atom.
Synthesis, characterization and cancer cell growth inhibition activity of ruthenium(II) complexes bearing bidentate pyrrole-imine ligands
Chen, Guan-Hao,Leu, Wohn-Jenn,Guh, Jih-Hwa,Lin, Chia-Her,Huang, Jui-Hsien
, p. 122 - 130 (2018/05/28)
A series of bidentate pyrrole-imine ligands, [C4H3NH-(2-CH=N-R)] (1, R = cyclohexenyl; 2, R = CH2CH2-1-cyclohexenyl; 3, R = tBu; 4, R = CH2-2-furyl; 5, R = 2-methoxylphenyl; 6, R = phenyl;
Tunable fluorophores based on 2-(N-Arylimino)pyrrolyl chelates of diphenylboron: Synthesis, structure, photophysical characterization, and application in OLEDs
Suresh,Lopes, Patricia S.,Ferreira, Bruno,Figueira, Claudia A.,Gomes, Clara S. B.,Gomes, Pedro T.,Di Paolo, Roberto E.,MacAnita, Antonio L.,Duarte, M. Teresa,Charas, Ana,Morgado, Jorge,Calhorda, Maria Jose
, p. 4126 - 4140 (2014/04/17)
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{κ 2N,N-NC4H3C(H)=N-Ar}] (Ar=C6H 5 (12), 2,6-Me2-C6H3 (13), 2,6-iPr2-C6H3 (14), 4-OMe-C6H 4 (15), 3,4-Me2-C6H3 (16), 4-F-C6H4 (17), 4-NO2-C6H4 (18), 4-CN-C6H4 (19), 3,4,5-F3-C 6H2 (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., φf=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 (φf=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 (φf=0.005, 0.023, and 0.20 for Ar=2,6-Me2-C6H3 (13), 2,6-iPr 2-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-cdm-2 being achieved for a green-emitting device. Fluorescent N,N-boron chelate complexes: Mononuclear boron complexes of 2-(N-arylimino)pyrrolyl emit violet to bluish-green colors in solution (see figure, ITO=indium tin oxide, PEDOT:PSS=poly(3,4- ethylenedioxythiophene):poly(styrene sulfonic acid)), depending on the substituents on the N-aryl group. Organic light-emitting diodes have been successfully fabricated with the new boron complexes, achieving luminances of the order of 3000-cdm-2.
The behavior of pyrrolyl ligands within the rare-earth metal alkyl complexes. Insertion of CN and CO double bonds into Ln-σ-C bonds
Yang, Yi,Cui, Dongmei,Chen, Xuesi
experimental part, p. 3959 - 3967 (2010/07/04)
This paper presents some unusual reactions of lanthanide tris(alkyl)s or lanthanide mono-Cp′ (Cp′ = (C5Me4)SiMe 3) bis(alkyl)s with pyrrolyl ligands, and the η5- or η1-coordination mode of the pyrroly
Novel vanadium(iii) complexes with bidentate N,N-chelating iminopyrrolide ligands: Synthesis, characterization and catalytic behaviour of ethylene polymerization and copolymerization with 10-undecen-1-ol
Xu, Bao-Chang,Hu, Tao,Wu, Ji-Qian,Hu, Ning-Hai,Li, Yue-Sheng
body text, p. 8854 - 8863 (2010/02/16)
A series of novel vanadium(iii) complexes bearing iminopyrrolide chelating ligands [2-(RNCH)C4H3N]V(THF)2Cl2 (2a: R = cyclohexyl; 2b: R = Ph; 2c: R = 2,6-iPr2C6H 3; 2d: R = p-CF
Chelating N-pyrrolylphosphino-N′-arylaldimine ligands: Synthesis, ligand behaviour and applications in catalysis
Anderson, Carly E.,Batsanov, Andrei S.,Dyer, Philip W.,Fawcett, John,Howard, Judith A. K.
, p. 5362 - 5378 (2007/10/03)
Two families of variously-substituted N-pyrrolylphosphino-N′- arylaldimine ligands, 2-(aryl-NCH)C4H3N-PR2 {3a-d R = Ph; 4a-d R = Pri2N}, have been prepared from the corresponding pyrrolylaldimines 2.
