Building: OC 108B
Education and Appointments
Synthetic Inorganic and Organometallic Chemistry, Supramolecular Chemistry, Catalysis, Materials Chemistry, Clusters and Nanostructured Materials
Our research, in the general areas of synthetic and structural inorganic chemistry, is directed toward developing new paradigms of coordination chemistry and creating metal-containing functional materials. The underpinning of our program has been the coordination and organometallic chemistry of both transition and rare earth elements. The unique and frequently aesthetically pleasing structural features, interesting properties, and potentially significant applications of transition metal- and lanthanide-containing substances provide multifold impetus for our efforts. Specifically, we have been pursuing the chemistry and materials in the following four distinct yet intellectually intertwined research areas:
Design and Synthesis of Luminescent and Magnetic Metal Complexes
Developing functional materials for advanced technological applications has been an ultimate goal of our research. Toward this end, we have been pursuing the design and synthesis of metal complexes of the transition metal and lanthanide elements. Through judicious ligand design and the complexation of selected metal ions, complexes with potential applications as organic light-emitters or sensory materials have been achieved in our laboratory.
Functional Polynuclear Metal Complexes or Clusters
Metal complexes featuring a number of metal atoms, directly metal-metal bonded or through the interaction of bridging ligands, are a class of fundamentally interesting (because of their unique structural features and bonding characteristics) and practically significant (because of their useful applications) substances. We have been developing rational synthetic methodologies for the assembly of these otherwise elusive chemical entities and studying their interesting electronic, optical, magnetic, and catalytic properties with an eye on their materials applications. Envisioned are their uses as highly efficient contrast-enhancing agents in biomedical imaging, novel luminescent materials in organic light-emitting devices, and materials for magnetic storage.
Supramolecular Chemistry and Materials Supported by Structurally Well-defined Metal Clusters
Stimulated by the potential applications of transition metal clusters for catalysis and photovoltaics, we have spearheaded a research program aiming at bringing such substances out of the limited sphere of fundamental cluster chemistry and into general synthetic applicability. Utilizing metal clusters as atom-like building blocks with expanded dimensions and adjustable properties, we have been able to construct a great variety of supramolecular architectures wherein metal clusters are inter-connected to produce materials with interesting structures (e.g. nanoscopic pores) or intriguing properties (e.g. inter-cluster electronic communication).
Nanostructured Materials for Magnetic and Biomedical Applications
Our interest in cluster chemistry has extended into the study of nanostructured clusters, those containing lanthanide elements in particular. We have been focusing on the development of magnetic materials capable of magnetic storage. Specifically, by doping lanthanide ions into a matrix of superparamagnetic iron oxide nanoparticles, we have been able to demonstrate ambient-temperature ferromagnetism in these materials. In addition, in collaboration with Professors Cai and Hruby, we are presently developing nanostructured platforms labeled with disease-targeting moieties (e.g. peptides)for integrated diagnostic and therapeutic applications.
The chemistry involved in our research is not only driven by the exotic architectures of the molecules, but also by their potential to function as advanced materials. From a fundamental point of view, our program gains significance in that it interfaces with both chemistry and materials science. From a practical point of view, our efforts serve to provide new materials with applications ranging from catalysis, communication, to medicine. While rooted in traditional chemistry, the program often involves students in collaborations with an array of other scientists and engineers while crossing fields of chemistry, biology, and materials science. As such, the students' depth of fundamental chemical principles becomes augmented by exposure to a breadth of additional concepts. Such collaborative research often results in the creation of a fertile and creative environment for achievement of research goals.
1. "Keeping the ball rolling - Fullerene-like molecular clusters.” Kong, X.; Long, L.; Zheng, Z.; Huang, R.; Zheng, L. Acc. Chem. Res. 2010, 43, 201-209.
2. "Solvent-induced transformation of single crystals of a spin-crossover (SCO) compound to single crystals with two distinct SCO centers." Li, B.; Wei, R.; Tao, J.; Huang, R.-B.; Zheng, L.-S.; Zheng, Z. J. Am. Chem. Soc. 2010, 132, 1558-1566.
3. "Cluster-bound nitriles do not click with organic azides – Unexpected formation of imine complexes of the [Re6(µ3-Se)8]2+ core-containing clusters." Tu, X.; Boroson, E.; Truong, H.; Nichol, G. S.; Zheng, Z. Inorg. Chem. 2010, 49, 380-382.
4. "Cluster compounds of the f-elements." Zheng, Z. Handbook of Physical and Chemistry of the Rare Earth Elements 2010, 40, 109-240.
5. "A four-shell, 136-metal 3d-4f heterometallic cluster approximating a rectangular parallelepiped." Kong, X.; Nichol, G. S.; Long, L.; Huang, R.; Zheng, L. Harris, T. D.; Zheng, Z. Chem. Commun. 2009, 4354-4356 (cover illustration)
6. "A chiral 60-metal sodalite cage featuring 24 vertex-sharing [Er4(µ3-OH)4] cubanes." Kong, X.; Wu, Y.; Long, L.; Zheng, L. Zheng, Z. J. Am. Chem. Soc. 2009, 131, 6918-6919.
7. "Lanthanide-doped magnetite nanoparticles." De Silva, C.; Smith, S.; Shim, I.; Pyun, J.; Gutu, T.; Jiao, J.; Zheng, Z. J. Am. Chem. Soc. 2009, 131, 6336-6337.
8. "Crystal engineering supported by the [Re6(µ3-Se)8]2+ core-containing clusters." Tu, X.; Zheng, Z. CryEngComm. 2009, 11, 707-719 (cover illustration).