Lawrence Que Jr.

Lawrence Que Jr. is a chemist who specializes in bioinorganic chemistry and is a Regents Professor at the University of Minnesota, Twin Cities.

His group is also working towards designing functional models for iron enzymes and capturing, observing, and categorizing highly active metal-based intermediates.

Previous high-valent iron-oxo species have been noted and studied by observing [(Por•)Fe(IV)=O]+ in heme systems.

Que and his group studied various nonheme iron based complexes and through elaborate mechanistic work proved that Fe(V)=O species can indeed exist without the supporting heme ligand.

More specifically, one of Que’s focuses is on homoprotocatechuate (HPCA) 2,3-dioxygenase, which mediates the electron transfer between catechol substrates and O2 to form a [M(II)(semiquinone)superoxo] intermediate.

The structure of [Fe(II)(TPA)(CH 3 CN) 2 ] 2+ is the catalyst in this reaction scheme.
(HPCA) 2,3-dioxygenase with heme iron center. Each colored chain contains one iron heme center. The black sphere in the insert picture represents the iron nuclei. [ 17 ] [ 18 ]
A reaction scheme of Fe/Co-HPCD as a catalyst. [ 17 ] [ 18 ]
Crystal structure of trans-[Fe(IV)(O)(TMC)(NCCH 3 )](OTf) 2 . Orange sphere represents Fe, red sphere represents O, blue-purple spheres represent N, and gray spheres represent C. H atoms and OTf- counterions have been omitted. [ 19 ]