%0 Journal Article
%T Synthesis, Characterization, and Crystal Structure of Pyridinium Tetrakis{1-trifluoromethyl-3-(1¡ä-pyreno)-1,3-propanedionato}lanthanate(III) Complex
%A Tetsuji Moriguchi
%A Kenji Yoza
%A Akihiko Tsuge
%J Journal of Crystallography
%D 2014
%R 10.1155/2014/271238
%X The reaction of 1-trifluoromethyl-3-(1¡ä-pyreno)-1,3-propanedione with lanthanum(III) trichloride in the presence of pyridine leads to halide ligand exchange, yielding a novel pyridinium tetrakis{1-trifluoromethyl-3-(1¡ä-pyreno)-1,3-propanedionato}lanthanate(III) complex with four polycyclic aromatic hydrocarbon moieties. This reaction easily proceeds under mild conditions (25¡ãC, 24£¿h) producing the complex in a 90% isolated yield. The complex was characterized by infrared spectroscopy, proton nuclear magnetic resonance spectroscopy, and positive fast atom bombardment mass spectrometry, and its precise structure was determined by single crystal X-ray diffraction. Ultraviolet-visible spectroscopy, fluorescence spectroscopy, and X-ray analysis demonstrated that the four pyrene moieties were independently oriented. 1. Introduction In recent years, lanthanide(III) complexes with ¦Â-diketonato ligands consisting of various aromatic components have attracted numerous researchers [1]. These compounds represent well-known electronic and luminescent materials with numerous applications in material chemistry [2¨C4]. In addition, polycyclic aromatic hydrocarbons (PAHs), such as pyrene and perirene, have been highlighted by numerous researchers because of their electronic and luminescent properties [5¨C9]. From our recent work, the structures of the octadentate lanthanide(III) complex derived by X-ray analysis were reported to be unexpectedly cone-like [10]. The present study focuses on the synthesis and investigation of the structural properties of the novel octacoordinate lanthanum(III) complex with four bidentate ¦Â-diketonato ligands having four PAH (pyrene) moieties and one pyridinium ion as a counter cation. We also confirmed the exact structure of the octadentate lanthanide coordination complex having highly aggregated PAHs by X-ray analysis. 2. Materials and Methods All the reagents and solvents were obtained from commercial sources and were used as received. Infrared spectra were recorded on a HITACHI FT-IR 410X instrument using the KBr method. Proton nuclear magnetic resonance (1H-NMR) spectra were obtained on a Bruker 400£¿MHz Avance400S spectrometer at 293£¿K in chloroform-d3 using tetramethylsilane (Me4Si) as an internal reference. Positive fast atom bombardment mass spectrometry (pos. FAB-MS) spectra were obtained on a Noppon Densi JEOL JMS-SX102A spectrometer using nitrobenzylalcohol (NBA) as the matrix and dichloromethane (DCM) as the solvent. This instrument was operated in the positive ion mode using an m/z range of 100¨C2000. Elemental analysis was
%U http://www.hindawi.com/journals/jcrys/2014/271238/