Studies On Luminescent Hybrid Matcrials Doped With The β-Diketonated Lanthanide Complexes

The lanthanide complexes have excellent photoluminescent properties, such as sharp emission spectra for high color purity, broad emission bands covering the visible to near infrared region, a wide range of lifetimes, and high luminescence quantum efficiencies. However, the factors such as poor stabilities under high temperature or moisture conditions and low mechanical strength limit their practical use. In order to circumvent these drawbacks, lanthanide complexes have been incorporated into the matrices to constitute hybrid materials. The solid matrices could be divided into inorganic, organic and mixed matrices. The potential of these hybrid materials relies on exploiting the synergy between the intrinsic characteristics of host matrices (versatile shaping and patterning, excellent optical quality, high stabilities under high temperature or moisture conditions photosensitivity) and the luminescence features of trivalent lanthanide ions. These properties have attracted much attention for a wide variety of applications in the fields of lighting devices (light-emitting diodes (LED), optical fibers, optical amplifiers, lasers), and biomedical analysis (medical diagnosis and cell imaging).Our group is dedicated to the design and assembly of functional lanthanide-based hybrid materials. In order to assemble novel lanthanide-based materials and elucidate the effect of interactions between host and guest on the photophysical behaviors and stabilities of the materials, we designed and synthesized a series of β-diketonated lanthanide complex based materials on the basic of the previous studies. The lanthanide complexes were incorporated into inorganic matrix, inorganic-organic mixed matrix or organic matrix by weak interactions (such as hydrogen bonding, van der Waals forces, or weak static effects) or strong interactions (such as covalent or coordinate bond). The assembly of these materials would be applied to cell imaging white-light light-emitting diodes (LED), optical amplifiers and vapoluminescent sensor. It is found that the host-guest interactions have distinctive modulation effects on the photophysical behaviors and stabilities of the hybrid materials. The research results of this dissertation might have theoretical and practical significance for the design of functional lanthanide-based hybrid materials.The dissertation includes following four chapters:Chapter1:A brief review of investigation progress of lanthanide-based hybrid materials was summarized.Chapter2:Lanthanide complexes based inorganic matrices hybrid materials were assembled.Attapulgite (so-called palygorskite) is a hydrated magnesium aluminium silicate present in nature as a fibrillar silicate clay mineral. We discuss the preparation and luminescence of a europium complex covalently attached to attapulgite and SiO2nanoparticals, grafting the europium complexes with two alkoxide structures, APTES and APMDES. The composites display more efficient emission and improved lifetime in comparison with the isolated complexes, due to interactions of the complexes with the matrixes. The most efficient emission of Atta-APTES-cpa-Eu(DBM)3among the composites results from the uniformly structured ternary europium complexes.The development of sol-gel derived hybrid materials have been of widespread interest in materials science. Highly luminescent Eu(Ⅲ) and Tb(Ⅲ) complexes with a kind of amide-type β-diketone ligands, emitting in the green and red visible spectral regions upon UV irradiation, respectively, have been covalently bonded to the silica gels upon acidic hydrolysis and by using tetraethylorthosilicate as a silica source. The hybrids assembled by the ligand containing aromatic end group exhibited more effective intramolecular energy transfer, longer luminescence lifetimes and higher quantum efficiency. The above photoluminescence features indicated that the existence of a suitable conjugated system should allow a better energy transfer.Chapter3:Lanthanide complexes based inorganic-organic mixed matrices hybrid materials were assembled.Polymers are always incorporated into inorganic matrix to constitute inorganic-organic mixed matrix due to their several attractive features including mechanical strength, flexibility, and controllable cost. We assembled the ionic liquid-type lanthanide complexes onto attapulgite (atta). First, atta was anchored by1-propyl-3-methylimidazolium groups. Then we could prepare an immobilized analogue of the complex [C4mim][Ln(TTA)4] by an ion exchange route. The luminescence behaviors of the hybrid materials were investigated. The results of this work would have potential significance for the design and assembly of the luminescent lanthanide materials for high performance luminescence application.We also embedded a new terbium β-diketonate complex into silica gel and SiO2/polymer matrices containing the long organic carbon chains and inorganic network (Si-O-Si) through sol-gel process to assemble the hybrid polymeric materials, Tb-L xerogel and Polymer-Tb-L xerogels. As the data suggested, the polymeric hybrid materials in comparison with the isolated complex possess higher unit mass luminescence intensities and exposure durability. The polymers containing carbonyl groups are supposed to conduce to the energy transfer progress and the hydrogen bonding between the host and guest may affect the ligand-to-metal energy transfer.Chapter4:Lanthanide complexes based organic matrices hybrid materials were assembled.The full-color photoluminescence materials including a white-light-emitting film were designed and fabricated facilely with a fixed-component Ln-based (Ln=Tb and Eu) polymer hybrid doped with an amide-type β-diketonated ligand. The tunable photoluminescence emissions were achieved by changing the amounts of the hydroxides of the polymer hybrid as well as excitation wavelength, rather than varying the relative concentrations of the lanthanide ions and ligand. The film with good stability, sensitivity, reversibility, and quick response triggered by base-acid vapor would be available as a vapoluminescent indicator.