Michael Wolf

The discovery of new materials with electronic or photonic applications is the primary thrust of our research program. Projects in our lab involve the synthesis of new organic and inorganic materials, the study of the properties of such materials using a variety of techniques, and the development of molecule-based electronic devices including sensors, diodes and transistors.

We are investigating new molecular and polymeric materials for use as active components of organic based light-emitting diodes. Light-emitting diodes are useful components of many modern electronic devices. Their utility as lighting sources has been limited by their small size and limited color range, consequences of the use of inorganic semiconductors as their active components. Molecular materials offer advantages over the traditional materials in this area, because chemical synthesis can be easily used to modify the structure of the organic or inorganic emitter. In addition to the synthesis of new materials for light-emitting diodes, we are also interested in elucidating the details of the electroluminescence process in such devices. How electrical current can be most efficiently converted to light is an important question.

The modification of metal surfaces with covalently-bound, self-assembled monolayers is of interest to us. Since metal surfaces may be used as electrodes, such modification of the surface can result in cahnges in electrode behaviour. We are probing electron transfer processes across surfaces modified with monolayers of photo and electroactive coordination complexes. These surfaces may find application as components of high density memory storage devices.

We are synthesizing a new class of electronically conducting polymers which contain metal groups in the polymer backbone. These materials are of fundamental interest because the mechanism of conductivity may differ from purely organic conducting polymers. In addition, we are exploring the possibility of using metal-centered reactivity in these materials as the basis for chemical sensors in which bulk conductivity changes are used to monitor ligand concentrations.

Metal complexes containing hemilabile ligands (polydentate ligands containing both inert and labile coordinating groups) reversibly bind small molecules such as carbon monoxide. We have synthesized ruthenium polypyridyl derivatives containing hemilabile ligands, and have demonstrated that the photophysical properties of such complexes change upon binding small molecules at the hemilabile site. This behavior is being explored in an effort to develop chemical sensors in which the output is a change in the luminescence and absorption of the molecule.