The innovation engine for new materials

Nick Eckles

Nick Eckles


University of California, Santa Barbara




Alejandra Gómez-Torres

Faculty Sponsor(s): 

Skye Fortier

Faculty Sponsor's Department(s): 

Chemistry and Biochemistry

Project Title: 

Synthesis and redox character study of scandium complex supported by imidazolin-2-iminato and ketimine guanidinate donor ligands

Project Description: 

Scandium is a scarce and relatively expensive d-block element, typically considered a rare-earth element, which exhibits one of highest electropositivity values of the transition metals. The chemical properties of scandium are determined largely by its predominantly trivalent oxidation state, exhibiting properties more closely related to that of lanthanides. In this group’s past work with titanium, the reduction of Ti(IV) complexes was studied with the goal of accessing low valent titanium compounds and synthons. The synthesized complex, [(Ketguan)Ti(Cl)2(ImDippN)] (A)3 (Ketguan = [(tBu2C=N)C(NDipp)2]-; Dipp = 2,6-diisopropylphenyl; ImDippN = 1,3-bis(Dipp)imidazolin-2-iminato), was successfully reduced yielding the masked Ti(II) synthon (Ketguan)(η6-ImDippN)Ti (B). This electron rich platform has shown capable of mediating the catalytic hydrogenation of unsaturated hydrocarbons, reversible oxidative addition/reductive elimination of thiophene, and thiophene hydrodesulfurization; all of which are uncommon for early transition metal complexes. This rich chemistry of the highly reduced (B) synthon has motivated us to explore analogous platforms using scandium. Being located just left of titanium on the periodic table, scandium is a more electropositive metal and is thus more difficult to reduce. To the best of our knowledge, only one example of a Sc(II) compound has been reported. Therefore, through this project we aim to use the particular steric and electronic characteristics of our ligand scaffold to attempt the stabilization of low-valent scandium complexes. The scandium analog for (A), [(Ketguan)Sc(Cl)(ImDippN)] (C), will attempt to be synthesized in the same manner as the titanium complex.