Low-Coordinate Building Blocks for Cyanide-Based Single-Molecule Magnets

University Of Missouri-Saint Louis, Saint Louis MO

Investigators

Abstract

The Chemical Structure, Dynamics and Mechanisms Program supports Professor Stephen Holmes of the University of Missouri-St. Louis to investigate differences in magnetic behavior for modular building blocks and their polynuclear derivatives, as a function of transition metal substitution, linking and ancillary ligands, coordination environment, and spin ground state degeneracy. Efforts to understand how single-ion magnetic anisotropy translates into magnetic properties exhibited by a series of structurally related bi- and trinuclear complexes will be explored. Several 3- and 4-coordinate molecular building blocks containing paramagnetic centers with orbitally degenerate spin ground states will be constructed; sterically demanding ligands will enforce this geometry and allow for efficient spin-orbit coupling interactions. Elucidating origins of how single-ion magnetic interactions assist in the formation of polynuclear complexes that spin ground states with exceptionally large zero-field splittings are the goals of this effort. Several bi- and trimetallic single-molecule magnetic complexes (SMMs) containing linear M-X-M´ bridges, where X = cyanide and 1,4-butadiynylide, will be explored using purposefully designed precursor complexes. Structure-property relationships will be drawn and used to refine our understanding of how orbitally degenerate and anisotropic spin centers can be designed and used to construct SMMs. The proposed research will impact efforts to use soluble transition metal complexes as switchable components in a range of information storage technologies. Proposed domestic/international collaborations and exchanges will allow participating students to develop a global perspective of science, establish potentially life-long collaborations, and afford access to complementary skills and expertise currently unavailable at their home institutions. Mentorship of numerous undergraduate, ACS SEED, and regional STARS (Students and Teachers as Research Scientists) students and high school teachers within the greater St. Louis region will continue to be integral to research efforts.