Group Page

Associate Professor
Ph. D., Colorado State University
Physical Inorganic Chemistry

The Rack research group is interested in the design and characterization of inorganic molecules with specific electronic structures for applications in energy storage, solar energy conversion and electron transfer. A major thrust of our group focuses on the preparation and examination of molecular photochromic and electrochromic compounds. Typically, our strategy employs molecules exhibiting Charge-Transfer (CT) photochemistry, an isomerizable ligand, and a metal atom capable of one electron redox chemistry. Ancillary ligands further modulate the spectroscopic properties of the complex. The mode of action in these complexes is an electron-transfer triggered linkage isomerization which results in a dramatic change in both the absorption spectrum and the reduction potential of these complexes. Typical characterization techniques in the group are electrochemistry, spectroelectrochemistry, UV-vis absorption, variable-temperature emission (steady-state and time resolved) and transient absorption spectroscopy as well as other instrumentation for routine analysis (NMR, IR, X-ray crystallography). While we are ultimately interested in device applications for these compounds, we are compelled to understand the mechanism of action in these and other photoactive molecules. As a result, many of the group members embrace an iterative synthesis and measurement approach in the design of target molecules.

N. V. Mockus, J. L. Petersen, and J. J. Rack, "Subnanosecond Isomerization in an Osmium-Dimethylsulfoxide Complex"Inorg. Chem. 2006, 45, 8-10.

A. A. Rachford, J. L. Petersen, and J. J. Rack, "Designing Molecular Bistability in Ruthenium Dimethylsulfoxide Complexes"Inorg. Chem. 2005, 44, 8065-8075.

J. J. Rack, A. A. Rachford, and A. M. Shelker, "Turning-Off Phototriggered Linkage Isomerizations in Ruthenium Dimethylsulfoxide Complexes."  Inorg. Chem. 2003, 42, 7357-7359.

J. J. Rack and N. V. Mockus, "Room-Temperature Photochromism in cis- and trans-[Ru(bpy)2(dmso)2]2+" Inorg. Chem. 2003, 42, 5792-5794.

J. J. Rack, T.M. McCleskey, E.R. Birnbaum, “Perturbing the Sequestered Water-Pool in Microemulsions:  The Role of the Probe in Affecting Reverse Micelle Equilibria.”.  J. Phys. Chem B. 2002, 186, 632-636. 

E. S. Krider, J. J. Rack, N. L. Frank and T. J. Meade, "Automated Synthesis of 3’-Metallated Oligonucleotides." Inorg. Chem ., 2001 , 40 , 4002-4009.

J. J. Rack , J. R. Winkler and H. B. Gray, “Phototriggered Ru(II)-dimethylsulfoxide Linkage Isomerism in Crystals and Films.” J. Am. Chem. Soc. , 2001 , 123 , 2432-2433.

J. J. Rack, E. S. Krider, and T. J. Meade, “Electrochemistry and Spectroscopy of Ruthenium-Modified Nucleic Acids:  Design of a Novel Metal-Binding Nucleoside.” J. Am. Chem. Soc. , 2000 , 122 , 6287-6288.

J. J. Rack and H. B. Gray, “Spectroscopy and Electrochemistry of mer -Ru(Cl)3(dmso)(tmen).  Dimethylsulfoxide is S-bonded to Ru(II), Ru(III), Ru(IV).” Inorg. Chem. , 1999 , 38 , 2-3.