Synthesis of novel ligands for biphasic media. Exploration
of alterative reaction media, specifically those of water and ionic
liquids for catalytic hydroformylation and hydrogenation
reactions. Development of task specific ionic liquids.
Developing new methodologies for undergraduate science
education.
Synthesis of Environmentally Friendly
Catalysts
Our laboratory is interested in the design and
implementation of environmentally safe and efficient catalytic
systems. Traditionally, industry conducts large-scale catalytic
reactions within environmentally harmful organic solvents.
Recently, the use of ionic liquids has received attention as an
alternative media for biphasic catalytic reactions. These
liquids are salts that melt at low temperatures (<100 C), have
no appreciable vapor pressure, and possess excellent chemical
stability. Many organic compounds have low solubility in
ionic liquids making these systems biphasic and products easy to
separate. Products that are soluble in the ionic media can be
easily separated by distillation since the ionic liquids have
virtually no vapor pressure.
Our interest within this field involves design of new ligands and
catalysis to function specifically, and therefore more efficiently,
within the ionic liquid media. Typically this involves
grafting the same functionality of the ionic liquid onto one or
more of the ligands surrounding the catalyst. Currently, we
have applied this technology to the hydrogenation of polymers and
hydroformylation of simple olefins.
Students involved these projects become exposed to organic
synthesis, inorganic synthesis, modern instrumentation, polymers,
ionic liquids, and catalysis.
Development of catalytic compounds containing N-heterocyclic
carbene complexes
N-heterocyclic carbenes have received some attention in the
literature as possible replacements for phosphine ligands in many
catalytic reactions. These ligands coordinate about ten times more
strongly than their phosphine analogs. This is important since in
many catalytic reactions loss of the phosphine ligand is the most
common way the catalytic cycle shuts down. However, this same
effect also makes these ineffective ligands in traditional
monomeric hydroformylation catalysts as such ligands also stabilize
the coordination of carbon monoxide and thus shuts down the
catalytic cycle.
We are currently investigating the use of -N-heterocyclic
carbene complexes as ligands for both monomeric and dimeric rhodium
complex systems. Thus far this ligand system has proven to be
easily tunable both electronically and structurally, more stable,
and easier to modify and their phosphine analogs.
Students involved these projects become exposed to ligand and
catalyst design, organic synthesis, inorganic synthesis,
modern instrumentation and catalysis.