• Synthesis of novel main-group compounds which
  might be precursors for electronic materials

Synthesis of novel main-group compounds which might be precursors for electronic materials

The chemistry of organometallic main-group compounds and of materials are brought together in Dr. Beachley's research program. Research activity is directed toward the preparation and characterization of interesting but important new compounds which have the potential to make new electronic materials or to solve problems which have been identified as being significant to the formation of currently useful materials such as semiconductors. The future of new high speed electronics will probably involve group 13-15 materials such as GaAs, InP and related materials. However, for these types of materials to achieve their potential, chemists need to discover new precursors and novel reactions which will occur at lower temperatures and produce fewer impurities than those currently used.

Current research has focused on the synthesis, characterization and reaction chemistry of compounds of group 13 elements in oxidation states other than the typical +3 and of compounds which can be envisioned to be converted to reactive species in lower oxidation states. This work has been designed to discover new routes to low oxidation state compounds, and to determine what are the chemical characteristics of ligands which stabilize low oxidation state group 13 compounds; what is it the molecular structure of the compound in the different states of matter including the solid and gas phases and in solution and what reactions might the compound undergo which might be useful for the preparation of materials at "low" temperatures. Examples of low oxidation state compounds which have been prepared by graduate students in Dr. Beachley's laboratory include In(C5Me5), [Ga(CH2CMe3)]n and [Ga(CH2CMe2Ph)]n. The indium(I) compound In(C5Me5) reacts with P4 at 175°C to form InP whereas the typical reaction to make InP requires ~650°C. Similarly, the gallium(I) compound, [Ga(CH2CMe3)]n, reacts with NH3 at 460-480°C to form GaN whereas related reactions of organogallium(III) compounds need ~1000°C.

The reaction of In(C5Me5) with P4 to form InP at 175°C prompted investigations of the chemistry of Et2Ga(C5H5), a compound which can be envisioned to form [Ga(C5H5)] and might be used to prepare GaP or GaAs at "low" temperatures. Characterization of Et2Ga(C5H5) uncovered a most unusual compound. Even though an X-ray structural study identified a polymer of Et2Ga(C5H5) simplest units, the compound does not exist as a single pure compound in either the liquid state or in benzene solution. Surprisingly, the pure compound can be reformed by recrystallization of a benzene solution. Can you explain these observations or identify the species which are present in the melt or in solution? Students find the chemistry of the group 13 elements to be full of surprises as they prepare and thoroughly characterize new compounds.

Selected Recent Publications