| Aromatic heterocyclic derivate compounds of 1,10-phenanthroline bearing delocalized π-systems are often formed by donor-acceptor (D-A) spacers. The bidentate chelate nitrogen atoms in 1,10-phenanthroline are easily coordinated with metal ions. These ligands which have potential applications on organic and polymeric light-emitting devices, photoconductive materials, photovoltaic solar cells and field-effect transistors has attracted much attention in coordination chemistry. Advanced functional materials might be achieved by combination of metal ions and 1,10-phenanthroline derivate ligands functionlized by optical-sensitive thiophen groups.The d6 transition metal complexes with heteroaromatic ligands have been the subject of intense investigations for many years. Among them, the most frequently studied compounds are complexes incorporating the [Re(CO)3] fragment and phen-like ligands, which have Optical performance and can be potentially used for dye sensitized solar cells (DSSCs), nonlinear optical (NLO), light emitting diode (LED), etc. Their photobehaviour may be discussed in terms of three types of excited states:(1) metal-to-ligand charge transfer (MLCT) states, (2) ligandto-ligand charge transfer (LLCT) states, (3) intraligand (IL) states. Several [Re(CO)] complexes have been used as electroluminescent materials in OLED-type devices so far.The content includes two parts as follow:1. Two thiophen functionalized 1,10-phenanthroline ligands TIP/5-Br-TIP have been used to prepare transition matel and rare earth complexes 1-10. The luminescent properties have been investigated and discussed.A family of ternary β-diketonate lanthanide(Ⅲ)-cored complexes based on the combination of 2-(5-bromothiophen)imidazo[4,5-f][1,10]phenanthroline (5-Br-TIP)/ 2-thiophenimidazo[4,5-f][1,10]phenanthroline (TIP) and 2-thenoyltrifluoroacetonate (TTA) ligands have been described herein, i.e. Ln(TTA)3 (5-Br-TIP) [Ln= Eu (1), Dy (2), Er (3), Tb (4), Sm (5), Yb (6)] and Eu(TTA)3(TIP) (7). According to the fluorescence spectra of complexes 1,3,5,6 and 7, characteristic luminescence of Ln3+ ions in the visible and near-infrared band ranges is observed which is attributed to the efficient energy transfer from the ligands to the metal centers. Room fluorescence intensity of 7 is analogous to that of a strong fluorescent complex Eu(TTA)3(phen), but the fluorescence intensity of 1 is much weaker.Three mononuclear cadmium(Ⅱ), manganese(Ⅱ) and nickel(Ⅱ) complexes having 2-thiophenimidazo[4,5-f)[1,10]phenanthroline (TIP) and 2-(5-bromothiophen)imidazo [4,5-f][1,10]phenanthroline (5-Br-TIP) ligands formulated as [cis-Cd(NO3)(TIP)2] (8), [cis-MnCl2(5-Br-TIP)2] (9) and [cis-NiCl2(TIP)2] (10), have been synthesized and structurally compared. They are characterized by elemental analysis, FT-IR, UV-vis spectra, luminescence spectra and X-ray single-crystal structural analysis. All of them are 1:2 mononuclear complexes with the same cis configuration, among which complex 8 is eight-coordinated and the others are six-coordinated. Ligands TIP and 5-Br-TIP in complexes 8-10 are essentially planar with the dihedral angles between imidazole and thiophene rings in the range of 3.9(1)-9.2(1)°.2. Seven Re(Ⅰ) complexes 11-17 having 3,8-extended 1,10-phenanthroline-based heterocyclic aromatic ligands L1-L7 have been synthesized and qualitatively studied.3,8-extended 1,10-phenanthroline ligands react with Re(CO)5-Cl to synthesize a series of Re(Ⅰ) complexes, which are mononuclear structure and have optical properties and structure characteristics due to the great delocalized π-systems. All of them are characterized by elemental analysis, FT-IR, UV-vis spectra, luminescence spectra and X-ray single-crystal structural analysis. According to the fluorescence spectroscopy, we have detected characteristic luminescence of Re ion corresponding to the MLCT transition.11,12,13,14 and 16 all crystallize in the triclinic space group P1. In contrast,15 crystallizes in the monoclinic space group P21/c and 17 crystallizes in the orthorhombic space group Pbca. Compounds 11-14 show good planarity with dihedral Angle range of 2.3(3)°-20.8(6)° between thiophene ring and adjacent phenanthroline unit, and the minimum value is 2.3(3)°in 13. While, planarity of 15-17 based on the phenyl-expand ligand is poorer with the dihedral angle range is 13.4°(9)-37.5(9)°between benzene ring and adjacent phenanthroline unit. Several π-π stacking interactions and p-π stacking interactions are found between adjacent molecules... |
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