Kenneth C. JandaProfessor, Chemistry |
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Research Interests |
Chemical Physics, Gas Hydrate Clathrates, van der Waals Clusters | |
| URL | Research Group Web Page | |
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Academic Distinctions |
Sigma Xi Undergraduate Research Award National Science Foundation Predoctoral & Postdoctoral Fellow Alfred P. Sloan Fellow Camille and Henry Dreyfus Foundation Teacher-Scholar Fulbright Fellow Fellow of the American Physical Society |
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| Appointments |
Research Associate, The University of Chicago 1977-1978 Visiting Professor, Universit de Paris-Sud, 1986 Visiting Professor, Universit Paul Sabatier, 1996 |
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Research Abstract |
Determining the structure of a wide variety of molecules and relating structural information to chemical properties is one of the most important achievements of chemical physics. Progress along these lines requires close cooperation between theory and experiment. The theories that underlie interpretation of molecular spectra are now so well established that they are often taken for granted. The direct prediction of molecular structure by theory is also becoming part of the accepted arsenal of a chemist's tools. Our research has the joint goals of understanding the structural properties of ever more complicated chemical systems and achieving similarly powerful understanding of the underlying principles of chemical dynamics. At present, we study several types of problems for which the role of experiments and theory are equally important for providing a fundamental understanding of the under lying processes. In one such study we are measuring how the electronic wave function of a molecule changes as it dissociates. For instance, for the A state of the ICl molecule we have recorded the electronic spectrum of ICl with sufficient resolution to determine the hyperfine constants for wide range of vibrational levels and this allows us to determine the configuration of the valence electrons as a function of the bond length. The results indicate that the LCAO-MO model presented in text books is not very useful for describing this state. We have also determined the structures of a large number of complexes that involve one, two, or three noble gas atoms weakly bonded by van der Waals forces to a chlorine or a bromine molecule. High-resolution spectroscopy of these clusters reveals their geometrical structures, and pump-probe spectroscopy yields the lifetimes and dynamics of intramolecular vibrational energy transfer processes. Rigorous quantum mechanical analysis of the data reveals both the nature of the energy transfer mechanism within the complex and the kinematics of the dissociation. Another system of interest is that of large helium clusters that contain up to 10,000 He atoms. Such clusters provide a unique medium for chemistry because evaporation holds the cluster temperature to about 0.5K. This allows otherwise extremely unstable species to coexist. We are learning how to deposit reactive species into the cluster and to use the cluster to deposit the reactive species onto a surface without inducing reaction. Finally, we are studying a novel form of solids called gas hydrate clathrates. In these solids, water molecules form a hydrogen bonding network slightly higher in energy than pure ice, but whose structure consists of interconnected cages. The cages contain gas molecules such as chlorine, propane or methane, which the van der Waals reactions between the gas molecule and the cage are sufficient to stabilize the gas hydrate clathrate. In essence, the gas molecule is in a sub-nanoscopic vacuum chamber.  |
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| Publications | Time dependent pump-probe spectra of NeBr2, Jose A. Cabrera, Craig R. Bieler, Benjamin C Olbricht, Wytze van der Weer and Kenneth C. Janda, J. Chem. Phys. 123, Art. No. 054311, (2005). | |
| Structure and stability of Ne+Hen: experiment and diffusion quantum Monte Carlo theory with on the fly electronic structure, Carrie A. Brindle, Melissa R. Prado, Kenneth C. Janda, Nadine Halberstadt and Marius Lewerenz, J. Chem. Phys. 123, Art. No. 064312, 2005. | ||
| Anharmonic Vibrational Spectroscopy Calculations for (NH3)(HF) and (NH3)(DF): Fundamental, Overtone, and Combination Transitions, Carrie A Brindle, Galina M. Chaban, R. Benny Gerber and Kenneth C. Janda, Chem. Phys. Phys. Chem., 7, 945-954 (2005). | ||
| "Transition from Hydrogen Bonding to Ionization in (HCl)n(NH3)n and (HCl)n(H2O)n Clusters: Consequences for Anharmonic Vibrational Spectroscopy." Chaban G. M., Gerber R. B., Janda K. C. J. Phys. Chem. 2001, 105, 8323-8332. | ||
| "The Dynamics of Noble-Gas Halogen Molecules and Clusters," Andreas Rohrbacher, Nadine Halberstadt and Kenneth C. Janda, Ann. Rev. Phys. Chem. 2000, 51, 405-33. | ||
| "Structure and spectroscopy of the He2Cl2 van der Waals cluster," Marta I. Hernndez, Nadine Halberstadt, William D. Sands and Kenneth C. Janda, J. Chem. Phys. 2000, 113, 7252-7267. | ||
| "Charge Transfer and Fragmentation of Liquid Helium Droplets doped with Xenon," Thomas Ruchti, Berton E. Callicoatt and Kenneth C. Janda, Physical Chemistry Chemical Physics 2000, 2, 4075-4080. | ||
| "Measurement of the electronic wave function: Separated atom wave function analysis of the R-dependent hyperfine constants of the iodine monochloride A state," William S. Barney, Colin M. Western and Kenneth C. Janda, J. Chem. Phys. 2000, 113, 7211-7223. | ||
| Link to this profile | http://www.faculty.uci.edu/profile.cfm?faculty_id=2048 | |
| Last updated | 09/30/2005 | |
