The general interesting of this group is focused on self-assembly which provides a synthetic approach to the functional assemblies resulting in better functional materials. Self-assembly involves spontaneous assembly of well-defined and complex molecular entities from constituent subunits into stable aggregates without direct human or mechanical interference. The ordered assemblies/aggregates display distinct properties not present in the original components. This has largely been achieved using a principle which has itself been borrowed from biology: spontaneous organization of discrete component subunits into an ordered structure driven thermodynamically to lower energy. Unlike biology, however, self assembly in coordination chemistry occurs through the formation of coordinate bonds rather than weak inter- or intramolecular interactions. Therefore, coordination chemistry provides a useful tool not only in the elucidation of the self-assembly process itself, but also in design self-assembling systems at a variety of scales, and to use these systems to form working devices in a bottom-up approach that would be difficult or practically impossible to build with any other technique.
Specific research topics of current interest include:
(1)design, synthesis and properties of functional molecular systems:
The aim of our work is 3-fold: (i) to highlight the diversity of structural and magnetic interactions in coordination complexes, and thus to investigate and understand the magneto-structural correlations. (ii) to prepare novel multifunctional organic-inorganic hybrid molecular materials by introducing stable and easy-to-tailor organic molecules with electric and optical properties, and to establish general principles for the construction of multifunctional molecular materials. (iii) to obtain the solid functional materials in crystalline or amorphous state along the lines of that many materials are required to be in the solid state without their distinct properties lost for practical applications.
(i)This project involves design and preparation of polynuclear and multidimensional complexes containing paramagnetic centers connected through pseudohalide bridges to investigate the mechanism of superexchange magnetic interactions and magneto-structural correlations.
(ii)Based on the structural and photochromic features of organic photocheomic compounds and the specific properties of metal ions, this project aims partly to obtain novel metal-organic hybrid molecules, and to study the interplay between the photochromic moiety and the metal chromophores.
(iii) We have recently begun a project to obtain novel mutifunctional solid-state materials through the carefully selection of substrates, such as silica and gold film, to solidify the functional molecules as prepared in project ii, which will show dual information memory functions or dual optical switch functions, which arising from the photochromic and photomagnetic properties of the functional molecules.
(2)The study of synthesis, structure and applications of Rare-Earth functional materials.
Nanometer size inorganic crystals are playing an increasingly important role in solid state physics, chemistry, materials science, and biology. Many fundamental properties of a crystal (e.g., ionization potential, melting point, band gap, saturation magnetization) depend upon the solid being periodic over a particular length scale, typically in the nm regime. Also, the phase, shape and size of the rare earth functional nanomaterials are extensively synthesized in a controllable way via tuning the coordinated interaction between complex molecules and the nanocrystals. Based on the restrcition of the coordinate compounds, we focus on illustrating the mechanism of the growth of nanocrystals and developping new functions of the nanocrystals base rare earth nanomaterials.
1. The synthesis of monodisperse inorganic rare earth compounds in high boiling solvent. The ability to make nanocrystals of high quality (uniform size, no defects except the ones we want, designed surface, etc.) is key in this part, and we are also interested in its own right. We grow nanocrystals by thermolysizing organometallic precursors into hot surfactants. We focus on some important questions of solid-state chemistry: How does nucleation of a solid occur? What governs the rate of growth of a crystal? In addition to fundamental studies of nanocrystal synthesis, we are interested in developing new properties relative with nanocrystals and methods for controlling nanocrystal self-assembled behavior.
2. Solvothermal and hydrothermal synthesis of rare earth functional materials in coordinated molecules solution. In this part, we focus on illustrating the function of the rare earth compounds connected with the properties of nanocrystals, such as phase, size, shape and so on. By precisely controlling the phases, sizes, shapes and surface of the nanocrystal through the complex molecules, we try to design the suitable functional materials for best application.
3. Biofunctionalization of high quality rare earth nanomaterials. The application of nanoparticles in bioscience is based on the suitable size distribution and unique fluorescent properties (broad absorption, narrow emissions, large Stokes shifts, photo-stability, up-conversion…). In this part, we focus on synthesizing high luminescent, water-soluble, biocompatible rare earth doped nanoparticles. How to synthesize the nanoparticles with suitable sizes and high fluorescent properties? How to modify the nanoparticles made them watersoluble and biocompatible? How to apply the nanoparticles in bio-systems? They are three main topics we are interested in.
