197009-47-5Relevant academic research and scientific papers
Highly Fluorescent Red-Light Emitting Bis(boranils) Based on Naphthalene Backbone
Urban, Mateusz,Durka, Krzysztof,Jankowski, Piotr,Serwatowski, Janusz,Luliński, Sergiusz
, p. 8234 - 8241 (2017)
Ten bis(boranils) differently substituted at the boron atom and iminophenyl groups were synthesized from 1,5-dihydroxynaphthalene-2,6-dicarboxaldehyde using a simple one-pot protocol. Their photophysical properties can be easily tuned in a wide range by the variation of substituents. Their absorption and emission spectral bands are significantly red-shifted (λmax = 495-590 nm, λem = 533-683 nm) when compared with simple boranils, whereas fluorescence quantum yields are strongly improved to reach 83%. The attachment of pendant NO2 and NEt2 groups at the opposite positions of the π-conjugated bis(boranil) scaffold resulted in the formation of an unprecedented system featuring push-pull architecture.
Tuning of the colour and chemical stability of model boranils: A strong effect of structural modifications
Wesela-Bauman, Grzegorz,Urban, Mateusz,Luliński, Sergiusz,Serwatowski, Janusz,Wo?niak, Krzysztof
, p. 3268 - 3279 (2015/03/18)
A series of diarylborinic complexes with salicydeneaniline ligands bearing various functional groups at the 6-position have been synthesized in high yields by applying a straightforward one-pot multicomponent protocol. UV-Vis measurements revealed the influence of electronic character of substituents on the observed maximum of emission (λem). This has been confirmed by a relatively strong linear correlation (R2 = 0.92) of λem with Hammett σp+ constants. Such a correlation was investigated using a QTAIM analysis of the charge density distribution. Absorption and emission bands for the obtained systems span between 390-437 nm and between 506-590 nm, respectively, with quantum yields reaching 17%. Time-dependent UV-Vis absorption measurements revealed that diphenylborinic salicydeneaniline complexes undergo slow degradation in solution under ambient conditions. In contrast, the use of a naphthalene-based chromophore or the introduction of fluorinated phenyl groups at the boron atom resulted in stable systems.
Synthesis of cyclopentadienyl-, indenyl-, and fluorenylbis(pentafluorophenyl)boranes as ligands in titanium and zirconium half-sand wich complexes. The crystal structures of C13H9B(C6F5) 2·t-BuNH2, C13H8SiMe3B(C6F5) 2, and {η5-C5H
Duchateau, Robbert,Lancaster, Simon J.,Thornton-Pett, Mark,Bochmann, Manfred
, p. 4995 - 5005 (2008/10/08)
Bis(pentafluorophenyl)boron fluoride (C6F5)2BF·OEt2 (1), readily accessible from BF3·OEt2 and 2 equiv of C6F5MgBr, reacts with fluorenyllithium to give (Flu)B(C6F5)2 (4), while the reaction with indenyllithium leads to the regioisomers 1- and 2-IndB(C6F5)2 5 and 6, which are separated by fractional crystallization. 4 and 5 form crystalline adducts with tert-butylamine. The trimethylsilyl derivatives Flu(SiMe3)B(C6F5)2 (9) and Ind(SiMe3)B(C6F5)2 (10) are similarly prepared. Heating (C6F5)2BF·OEt2 leads to ether cleavage and formation of (C6F5)2BOEt. Treatment of 5 and 6 with Zr(NMe2)4 at room temperature gives indenylzirconium amido half-sandwich complexes; however, the reaction is accompanied by the unexpected exchange of one boron-C6F5 substituent by NMe2, to form 1- and 2-{C9H6B-(C6F5)(NMe 2)}Zr(NMe2)3. Reaction with SiClMe3 affords the trichlorides 1- and 2-{C9H6B-(C6F5)(NMe 2)}ZrCl3. The NMe2 substituent reduces the Lewis acidity of boron, so that donor ligands such as THF or DME coordinate exclusively to zirconium. Whereas 9 and 10 fail to react with group 4 metal chlorides, the cyclopentadienylborane C5H4(SiMe3)B(C6F5) 2 undergoes smooth dehalosilylation with TiCl4 to give {C5H4B(C6F5)2}TiCl 3. Both 2-{C9H6B-(C6F5)(NMe 2)}ZrCl3 and {C5H4B(C6F5)2}TiCl 3 in the presence of low concentrations of AlEt3 are active ethene polymerization catalysts, while under comparable conditions mixtures of AlEt3 and either IndZrCl3 or CpTiCl3 are inactive. The molecular structures of (Flu)B-(C6F5)2·NH2CMe 3, Flu(SiMe3)B(C6F5)2, and {C5H4B(C6F5)2}TiCl 3 have been determined by X-ray diffraction.
