Characterization of Novel Metal Oxides
|Dr. Xiqu Wang
||Sang Ho Lee
The synthesis and properties of transition metal
oxide systems with layered or framework structures is the focus of this
research area. We study the synthesis of new compounds with asymmetric layer
structures , open framework structures that can absorb molecules and new
synthetic techniques including electrocrystallization under hydrothermal
Compounds with asymmetric layer structures are
inherently non centrosymmetric and can show nonlinear optical properties.
Systems we have investigated include layered molybdenum and tungsten oxides
based on the hexagonal tungsten oxide framework. These phases have the
composition A2(MO3)3XO3 where
A=alkali metal, M=Mo, W and X=Se or CH3P- and show nonlinear
optical properties. We are investigating synthesis of new phases with
suitable cromophores and the preparation of single crystal and thin films
for optical purposes.
We use hydrothermal synthesis and coordination
chemistry to construct new open framework structures. Recent examples
include assembly of cluster anions such as [V2P2BO10]618-
into framework structures, the synthesis of Ni(CN)4(Ph3Sn)2.xS,
a coordination system with a very low density framework and single crystal
growth and structure refinement of the titano-silicate ETS10.
Hydrothermal electrocrystallization and related approach that directly uses
dissolution of metals have led to the synthesis of a number of new phases
including a new family of Niobium phosphates.
Our current emphasis is on the synthesis of open
framework and microporous Vanadium, Niobium and Uranium metal silicates.
Research Supported by: National
Science Foundation, Robert A. Welch Foundation.