Dalton Transactions Blog

The 2013 Dalton Transactions Lecture awardees delivered their presentations at UC Berkeley last month. Each awardee is provided with an honorarium and a commemorative plaque. 

	Professor Trevor Hayton (UCSB) gave the annual Dalton Transactions Lecture, which is awarded to an exceptional young inorganic chemist in the Americas each year. Previous recipients are: 2012   Teri Odom (Northwestern University) 2011    Daniel Gamelin (U Washington) 2010    Paul Chirik (Princeton University) 2009    Francois Gabbai (Texas A & M University) 2008    Dan Mindiola (Indiana University) 2007    Geoff Coates (Cornell University) 2006    John Hartwig (University of Illinois at Urbana-Champaign) 2005    Kit Cummins (MIT) Professor Hayton has rapidly established himself as a leader in synthetic inorganic chemistry, focusing on actinides and bioinorganic systems. His lecture focused on the synthesis and reactivity of actinide complexes with chalcogenide ligands.  Professor Hayton received his B.Sc. in Chemistry from the University of British Columbia, whereupon he began his Ph.D. research, also at UBC, under the direction of Peter Legzdins. After graduating in 2003, he began a postdoctoral fellowship at Los Alamos National Laboratory before joining the faculty at University of California, Santa Barbara in 2003.
	The inaugural Dalton Transactions Distinguished Lecture was given on February 7 by Professor Phil Power of UC Davis. Professor Power is a world-renowned expert in main group chemistry. His Dalton Transactions Lecture focused on the preparation and structure of low-coordinate main group compounds and their reactivity towards small molecules such as dihydrogen and ethene.  Professor Power received his bachelor’s degree in chemistry from the University of Dublin, Ireland, and his doctorate from the University of Sussex; the latter under the supervision of Mike Lappert. He carried out postdoctoral research at Stanford University before joining the faculty at UC Davis in 1980. He was award the Royal Society of Chemistry Mond Medal in 2005 and elected Fellow of the Royal Society in the same year.

 Congratulations to Professors Hayton and Power for their awards!

Posted on behalf of Ian Mallov, web writer for Dalton Transactions

The water oxidation reaction is one of the most fundamental in chemistry and likely to be one of the first students are introduced to. During the reaction, water and energy are combined to give oxygen gas, protons and electrons, with the latter used to reduce the protons and yield hydrogen gas. The storage of hydrogen gas is one proposed method of storing the energy generated from renewable sources as, by burning the hydrogen and regenerating water in the process, you can release and harness the energy as needed.

In order for the water oxidation cycle to result in a net energy gain, a catalyst is needed for the oxidation process, with the majority of current systems incorporating rare or expensive metals. In their recent Dalton Transactions article, Johnsson and co-workers used small, cluster compounds made of cobalt, selenium, oxygen and chlorine to catalyze water oxidation. Two of the compounds, Co₄(SeO₃)₃Cl₂ and Co₃Se₄O₁₀Cl₂, were previously unreported but are closely related to the third, known compound Co₅Se₄O₁₂Cl₂. To synthesise the molecules, the authors heated mixtures of CoO, SeO₂, and CoCl₂ to 550 °C in a furnace for a number of days, with different ratios of the starting materials used to produce the different compounds. Adding each compounds to a solution of phosphate buffer and Ru(bpy)₃(PF₆)₃ led to the evolution of oxygen gas, which, by further ¹⁸O labelling experiments, was confirmed to occur due to water oxidation. 

Catalytic oxygen evolution by cobalt catalysts

Analysis of a catalyst intended to facilitate sustainable energy storage should spur discussion of the environmental impact of making the catalyst.  The large energy input to heat the materials is a drawback.  But, if synthesized in good yield in solid-state (solventless) reactions, as done here, the reactions would score well on the E-factor scale, a metric measuring waste produced per mass of product that gives a more complete indication of material efficiency than the obsolete atom economy principle. 

Though the catalytic activity proved wanting, the simple compounds and syntheses here present an interesting strategy towards useful water oxidation catalysis. 

Find out more and download the article now:
Cobalt selenium oxohalides: Catalysts for Water Oxidation
Dalton Trans., 2013, DOI: 10.1039/C3DT53452A

Ian Mallov is currently a Ph.D. student in Professor Doug Stephan’s group at the University of Toronto. His research is focused on synthesizing new Lewis-acidic compounds active in Frustrated Lewis Pair chemistry. He grew up in Truro, Nova Scotia and graduated from Dalhousie University and the University of Ottawa, and worked in chemical analysis in industry for three years before returning to grad school.