Work in our group targets synthetic chemistry, with the primary goal being to make, purify, and study molecules and materials that are interesting by virtue of their chemical reactivity.
We have extensive experience in the synthesis and study of new and unusual molecular inorganic and organometallic compounds of the d-, p-, and f- block elements. The emphasis is on preparing compounds that exhibit novel reactivity and/or catalytic behavior, particularly in the context of activation of small molecules such as H2, N2, O2, CO2 and N2O. In addition to the dry-box and Schlenk techniques used to prepare and manipulate compounds, we exploit a variety of characterization methods, including multinuclear NMR, X-ray crystallography, EPR and electrochemistry.
The Arnold group is an active member of the Berkeley Center for Green Chemistry which aims to advance green chemistry principles and practice through interdisciplinary research, education, and novel collaborations among investigators working at the intersection of chemistry, toxicology, environmental health, business, law, and public policy.
Organometallic Chemistry and Catalysis
Here we focus on the design and synthesis of new ligands to support and promote novel chemistry at metal centers. Nitrogen donors are heavily employed, although recent work in the group has now expanded this chemistry to encompass electron-rich phosphines.
We have a long-standing collaboration in the area of Group 5 chemistry with Professor Robert Bergman and recently published preliminary results on studies of niobium imido complexes supported by beta-diketiminato ("Nacnac") ligands.
We are also collaborating with Professor Dean Toste's research group to explore the potential for reactive vanadium imido species to activate small molecules.
Materials Chemistry & Catalysis
We are working with colleagues from UC Berkeley and the Lawrence Berkeley National Laboratory to explore new catalytic materials for the synthesis of a new generation of fuel cells. We are particularly interested in examining new polymer-bound metal catalysts for O2 reduction, and new molecular catalysts for hydrogenation/dehydrogenation of small organic molecules as "virtual" hydrogen storage materials. Techniques involved include synthesis of inorganic, organic, and polymer materials, electrocatalysis, and computational studies.
This topic is focusing on interesting uranium (+3, +4, +5, +6 oxidation states) and thorium (+4 oxidation state) complexes, particularly with sterically demanding ligands and ligands utilizing soft-donor atoms. The complexes we synthesize can then be used as a base for exploring interesting reactivity with small molecules, ligand substitution chemistry and redox chemistry. Recent significant findings include the preparation and characterization of the first examples of actinide-group 13 element bonds as part of a collaborative effort involving colleagues from UC Berkeley and the Lawrence Berkeley National Laboratory.
Professor. B.Sc. Salford University (1982); Ph.D., Born 1959; University of California, San Diego (1986); Postdoctoral Fellow, Imperial College (1987-88); Royal Society University Research Fellow (1988-89); Faculty Associate Scientist, Lawrence Berkeley National Laboratory, Chemical Sciences Division; Sloan Fellow (1993-97); Director, Berkeley Center for Green Chemistry; Associate Editor, Dalton Transactions (2002-present).