158595-45-0Relevant academic research and scientific papers
Near-infrared photoluminescence of lanthanide complexes containing the hemicyanine chromophore
Van Deun, Rik,Nockemann, Peter,Parac-Vogt, Tatjana N.,Van Hecke, Kristof,Van Meervelt, Luc,G?rller-Walrand, Christiane,Binnemans, Koen
, p. 5441 - 5447 (2009/01/31)
The near-infrared luminescence properties of three (E)-N-hexadecyl-N′,N′-dimethylamino-stilbazolium tetrakis(1-phenyl-3-methyl-4-benzoyl-5-pyrazolonato) lanthanide(III) complexes are described. These three complexes, containing trivalent neodymium, erbium and ytterbium, respectively, show near-infrared luminescence in acetonitrile solution upon UV irradiation. Luminescence decay times have been measured. The complexes consist of a positively charged hemicyanine chromophore with a long alkyl chain and a tetrakis(pyrazolonato) lanthanide(III) anion. Because of the absence of an α-hydrogen atom in the pyrazolonato ligands, and because of the saturation of the coordination sphere by four bidentate ligands, the luminescence properties are enhanced when compared to, e.g. quinolinate complexes.
Langmuir Film-Forming and Second Harmonic Generation Properties of Lanthanide Complexes
Huang, Chunhui,Wang, Kezhi,Xu, Guangxian,Zhao, Xinsheng,Xie, Xiaoming,et al.
, p. 14397 - 14402 (2007/10/02)
A series of amphiphilic lanthanide complexes were designed and synthesized, in which the lanthanide complex anions act both as the counterions of hemicyanine and as the spacer within a Langmuir-Blodgett (LB) film.Studies on the surface pressure-area (?-A) isotherms of these complexes show that the film-forming properties can be clearly improved if appropriate β-diketone ligands were chosen.The effects of molecular structures of the complexes, including the variation of lanthanide central ions, the structures of β-diketone ligands, and the length of alkyl chains in hemicyanines, on the film-forming properties of the materials are discussed.From second-harmonic generation experiments, the largely enhanced second-order molecular hyperpolarizability of lanthanide complexes with good film-forming properties were obtained compared with the hemicyanine iodide.This effect may be due in part to the local field effect but primarily molecular ordering and ordered segregation of hemicyanine chromophores by the bulky lanthanide complex anions.The charge separation of the hemicyanine chromophores was supported by the crystal structure of a model complex.The homogeneity of the film was verified by low angle X-ray diffraction and also by the linear relationship of the absorbance vs the number of layers of the LB films of a selected complex.
Liquid-crystalline behaviors of lanthanide complexes containing hemicyanine
Wang,Huang,Xu,Zhou
, p. 223 - 225 (2008/10/08)
The liquid crystalline behaviors of four lanthanide complexes, (E)-N-hexadecyl-4-(2-(4-(dimethylamino)phenyl)ethylene)pyridinium tetrakis(1-phenyl-3-methyl-4-benzoyl-5-pyrazolonato)lanthanide(La, Nd, Dy and Yb)(III) have been investigated by using differential scanning calorimetry (DSC), thermogravimetric and differential thermal analysis (TG-DTA) and polarized optical microscopy. Except for the lanthanum complex, the other three complexes display mesogenic behavior with typical smectic mosaic textures. This is the second report on lanthanide metallomesogens since a discotic mesophase of substituted bis(phthalocyanine)lutetium was found.
