Texas Tech University
TTU HomeDepartment of Chemistry and Biochemistry Faculty Dr. Richard L. Redington

Dr. Richard L. Redington

Title:

Professor Emeritus

Education:

Ph.D., 1961, University of Washington; Fellow in Fundamental Research, 1961-64, Mellon Institue; Visiting Scientist, 1983-84, 1999, MIT

Research Area:

Physical Chemistry/Chemical Physics

Office:

Phone:

Email:

Chemistry 034

806-742-3088

Richard.Redington@ttu.edu

 

 

Principal Research Interests

Professor Redington's research concerns applications of spectroscopy to gaseous, solvated, and matrix isolated molecules for the determination of properties including molecular geometries, potential energy functions, excitation energy transfer dynamics, and solvation effects. Substances capable of quantum mechanical tunneling between equivalent energy minima are of particular interest. Sample molecules may possess an intramolecular hydrogen bond such as that of tropolone, C7H602 (2-hydroxy-2,4,6-cycloheptatriene-l-one), or no H-bond at all - as for 1,3-cyclobutadiene.

As suggested in one-dimensional form in the figure, valence isomerization by cyclobutadiene involves heavy atom tunneling as well as thermal excitation. Tropolone is studied because it demonstrates an exceptionally large and varied range of vibrational state-specific tunneling splittings in its ground and first excited singlet electronic states. It has an equal double-minimum potential energy surface in each electronic state, and questions addressed by the research concern the tunneling paths and tunneling rates followed by the molecule as it interconverts between the equal energy minima when different molecular vibrations are excited. Is the tunneling mechanism for tropolone based on fast, impulsive, H atom transfer followed by a slow heavy atom relaxation; is it based on concerted H atom and heavy atom motion; is it based on other principles? Careful studies of isotopically labeled molecules (isotopomers) help resolve these basic questions.

Ab initio quantum mechanical calculations are now able to play a crucial role in guiding interpretations of experimental data and suggesting new experiments. Quantum computations are routinely performed on the sample molecules of interest to predict and to test various properties including relative conformational energies, vibrational force fields and spectra, internal rotation barriers, reaction transition states, and solvation effects.

 

Representative Publications