| Because of the significant technical applications in sensor, laser system, optical telecommunications and fluorescent imaging, near-infrared (NIR) luminescence from lanthanide(Ⅲ) complexes such as Pr(Ⅲ), Nd(Ⅲ), Er(Ⅲ), Yb(Ⅲ) has attracted increasingly great interest over the last few years. For overcoming very low extinction coefficients resulting from parity-forbidden f-f transitions of lanthanides, a suitable light-harvesting chromophore as antenna to sensitise the NIR luminescence was often employed. In this thesis, the complexes of Zn(Ⅱ)-Schiff base were adopted as antenna groups for sensitizing the NIR luminescence from Nd(Ⅲ). By the approaches of "complex as ligand" and "node and spacer", twenty new Zn(Ⅱ)-Nd(Ⅲ)-Schiff base heterobinuclear or heteropolynuclear complexes were synthesized. Their crystal structures were all determined by X-ray single crystal diffraction. Near-infrared photoluminescence properties of these complexes were studied. By selecting a complex with preferable optical property from those, an OLED was fabricated and near-infrared electroluminescence was observed.Firstly, for optimizing the coordination environment and making Nd(Ⅲ) remote from high-energy oscillators such as solvent molecule containing hydroxyl, which will quench NIR luminescence partly, pyridine was introduced as axial ligand to Zn(Ⅱ). Four heterobinuclear complexes([Zn(μ-L1)Nd(NO3)3(Py)]·MeCN,2;[Zn(μ-L2)Nd(NO3)3(H2O)(Py)],4 ;[Zn(μ-L3) Nd(NO3)3(Py)], 6; [Zn(μ-L4)Nd(NO3)3(Py)]·MeCN, 8) with pyridine coordinating to Zn(Ⅱ) were synthesized and high-energy oscillators were removed from Nd(Ⅲ) for the complexes 2, 6, 8 thereinto. Meanwhile heavy-atom effect was proved to be capable of enhancing NIR luminescence remarkably. Two heterobinuclear complexes with chiral Schiff base ([Zn(μ-L5)Nd(NO3)2(OAc)],10;[Zn(μ-L6)Nd(NO3)3(DMF)2] ,12) were synthesized for illustrating the influence of chiral ligand on the coordination of Nd(Ⅲ). The effect of intermolecular interactions on NIR luminescence was studied by synthesizing three heterobinuclear complexes with pseudopolymorphism: [Zn(μ-L3)Nd(OAc)(NO3)2(DMF)]·Solvate(Solvate: EtOH (13), THF (14), MeCN (15)). Solid state NIR emission spectra indicate that strongπ-πstacking would quench NIR luminescence partly.Next, two heterotetranuclear complexes([Zn2(μ-L1)2Nd2(4,4'-bpy)(NO3)6]·Et2O,16;[Zn2 (μ-L1)2Nd2(4,4'-bpe)(NO3)6]·2H2O,17) were assembled by introducing 4,4'-bpy and 4,4'-bpe as bridging ligands. Stronger NIR luminescence was observed compared with that of heterobinuclear precursor. By employing 1,4-bdc as bridging liand,[Zn2(μ-L1)2Nd2(1,4-bdc)(NO3)4 (EtOH)2]·2MeCN (18),[Zn4(μ-L1)4Nd2(1,4-bdc)2](NO3)2·2Et2O·4H2O (19) and [Zn4(μ-L1)4-Nd2(1,4-bdc)2]·[Zn(μ-L1)Nd(NO3)3(OAc)2]2 (20) were synthesized under different solvent and reaction stoichiometry. Their NIR luminescence intensity decrease according to the sequence: 19>20>18. This confirms introducing polychromophores and polyemitters may enhance luminescence intensity efficiently. When isonicotinic acid (HIN) was used as bridging ligand, 2D coordination polymer [Zn(##-L1)Nd(IN)(NO3)2]n (21) and simple heterobinuclear adduct [Zn(μ-L3)Nd(IN)(NO3)2(DMF)] (22), which was dependent on the rigidity of Schiff base ligand, were obtained respectively.Heteropolynuclear complexes were also prepared without introduction of bridging ligand. Two trinuclear complexes ([Zn2(μ-L7)Nd(NO3)3(Py)2]·H2O,25;[Zn2(μ-L8)Nd(NO3)3(Py)2]·Et2O·H2O,27) were synthesized with pyridine as axial ligand to Zn(Ⅱ) and without high-energy oscillators within the coordination sphere of Nd(Ⅲ) because of decreased binding sites of corresponding ligand. Two cyclic tetranuclear complexes ([Zn(μ-L10)Nd(NO3)2-(DMF)(Py)]2·(Et2O)2,30; [Zn(μ-L9)Nd(NO3)2(DMF)2]2,33) were obtained under the driving of Nd-Ophenol complementary coordination. The intrinsic quantum yield of Nd(Ⅲ) emission and energy-transfer rate constant for these four compounds were determined.Lastly an NIR OLED device was fabricated by doping complex 25 ([Zn2(μ-L7)Nd(NO3)3 (Py)2]·H2O) into PVK as emitting layer and employing PEDOT-PSS as hole-injecting layer. The structure of device was ITO(20Ω/square)/PEDOT-PSS(70 nm)/PVK: Complex 25(30 nm)/Ca(100 nm)/Al(100 nm). A near-infrared irradiance of 1.8 nW·mm-2 and current intensity of 50 mA·mm-2 under driving voltage of 20 V was achieved, which demonstrates the value of potential applications in OLED for this kind of compounds.
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