A new class of materials for use in electric and electroluminescent devices having one or more phosphine oxide moieties bonded by single bonds to two outer groups. In embodiments having two or more phosphine oxide moieties, the two or more phosphine oxide moieties are further joined by a bridging group. By selecting appropriate bridging and outer groups, the new class of materials of the present invention enables designers to "tune" the electrical and electroluminescent characteristics of the materials. The phosphine oxide moiety restricts electron conjugation between the bridging and outer groups, isolating the bridging and outer groups from each other, and allowing the photophysical properties of the bridging and outer groups to be maintained in the molecule. The lowest energy component (bridging group or particular outer group) thus defines the triplet state, highest occupied molecular orbital and lowest unoccupied molecular energies for the entire molecule.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
 This invention was made with Government support under Contract DE-AC0676RLO1830 awarded by the U.S. Department of Energy and Grant DMR-9874765 awarded by the National Science Foundation. The Government has certain rights in the invention.