Organometallic and Inorganic Chemistry

supramolecular coordination polymers, magnetic materials, open-shell organometallics, actinide chemistry, metal-metal bonds

Compounds which contain unpaired electrons can be found throughout chemistry, from the active sites in many proteins to magnetic materials. The variety of spin carriers is impressive: such systems can involve transition metals, lanthanides and organic radicals. We are interested in all aspects of paramagnetic molecules, in particular focusing on the areas of advanced molecular magnetic materials and paramagnetic organometallic complexes.

Molecular Magnetic Materials are a new type of magnetic material composed of molecules rather than metal atoms. This fundamental difference allows us to create types of advanced materials that have 'radically' different properties compared to classical magnets. For example, molecular magnetic materials can be dissolved. They can be highly coloured or transparent. Imagine a luminescent magnet, a chiral magnet or magnetic polymers! These long-term goals have applications in the electronics and computer industries as information storage and display components, as sensors and as molecular switches.

We are also very active in the general synthesis and characterization of paramagnetic metal-containing coordination polymers for other applications that target luminescent, non-linear optical and zeolitic (porous) properties.

Paramagnetic Organometallic Complexes have been much less studied relative to the vast literature on diamagnetic organometallic complexes. We are interested in the synthesis, structural chemistry, reactivity and magnetic behaviour of this underexamined class of organometallics. To what extent does the presence of unpaired electrons at the metal centre affect the stability, structure and reactivity of these compounds? Reactivity studies in particular with respect to catalysis and redox chemistry are explored.

Current Research Programs:

Transition-Metal and Lanthanide-Based Supramolecular Coordination Polymers
Using combinations of paramagnetic transition metals, lanthanides and appropriate bridging ligands, we are pursuing novel molecular magnetic materials. Bridging ligands include metal-cyanides and phenylenes. In particular, the use of linear d10 metal cyanides such as [Au(CN)2]- that display strongly attractive metal-metal interactions are under investigation. The fundamental interactions between unpaired electrons are also examined.

Paramagnetic Transition-Metal Organometallics
The examination of paramagnetic (a) high-valent transition metal organometallics, (b) early/late heterobimetallic and (c) mixed-valent complexes are of particular interest. Ligand design and synthesis is an inherent part of this project.

Actinide Chemistry
As an extension of our research in both supramolecular coordination chemistry and paramagnetic organometallics, the chemistry of uranium complexes with a variety of ligand systems, from oxidation state +3 to +6 is explored. Actinides are relatively underexamined compared with their transition-metal counterparts and provide an exciting route into some unusual chemistry.

Spin Crossover Complexes for Molecular Electronics
Compounds which exhibit high/low spin transitions are synthesized and their magnetic and optical properties studied with respect to understanding and controlling the transition. The design of molecule-based information storage systems, switches and sensors is envisioned.

Graduate students who join my group will gain experience in a wide range of techniques including multinuclear NMR (and NMR of paramagnetic complexes), ESR, FTIR, UV-vis kinetics, cyclic voltammetry and thermogravimetric analysis. They are also exposed to a variety of magnetic measurement methods, including the use of a state-of-the-art SQUID magnetometer. The determination of solid state structures by X-ray crystallography plays a crucial role in this research and we routinely collect diffraction data and solve our own crystal structures. Students will be trained in the synthesis and manipulation of air and moisture-sensitive compounds using vacuum-line/Schlenk techniques and a state-of-the-art glovebox system.

Interested students are encouraged to contact me directly at dleznoff@sfu.ca.