Charles Parmenter received his B.A. at the University of Pennsylvania in 1955. He went on to receive his Ph.D. at the University of Rochester in 1963. Professor Parmenter came to Indiana University in 1964. He became a full professor in 1972 and was named a Distinguished Professor in 1988.
The use of laser-induced UV fluorescence spectroscopy with supersonic molecular beams is an instructive way to study the energy flow that enables chemical reactions to occur. We are learning in a most fundamental way how polyatomic molecules in collisions gain the vibrational (and rotational) internal energy that enables them to react. We study this collisional activation by allowing a molecule such as laser-excited formaldehyde or benzene in one molecular beam to collide with, say, He or H2 in another beam. We use the resulting state-to-state view of energy transfer to work with theoretical groups elsewhere who are developing predictive computational schemes for the collisional energy transfer.
Another series of studies is directed at learning about collision-free vibrational energy flow within activated molecules. This flow is a prelude to forming transition states. We study this picosecond process by fluorescence from laser-excited molecules in supersonic beams where molecular temperatures are only a few degrees Kelvin. We can see particularly the interactions between various types of molecular motions that underlie the energy flow. For example, laser spectroscopy has most recently taught us much about how the nearly free internal rotation of a methyl group attached to a benzene ring (toluene, a molecular helicopter, so to speak) accelerates vibrational energy flow within the aromatic ring.

Characteristics and Relaxation Dynamics of van der Waals Complexes between p-Difulorobenzene and Ne
T. Jayasekharan and C. S. Parmenter
J. Chem. Phys., 120, 11469-11478 (2004)
A Chemical Timing Method for Absolute Vibrational Relaxation Rate Constants in the Vibrational Quasi-Continuum Region of S1p-difluorobenzene.
U. S. Tasic and C. S. Parmenter
J. Phys. Chem. B, 108, 10325-10333 (2004)
Pleasures of Science with Students and Colleagues
C. S. Parmenter
J. Phys. Chem. A, 107, 10480-10483 (2003)
Non-Stern-Volmer Quenching of S1 pDFB Fluorescence by O2 and the Charge Transfer Complex.
U. S. Tasic, E. R. Davidson and C. S. Parmenter
J. Phys. Chem. A, 107, 3552-3558 (2003)
Absolute Rate Constants for Collisional Vibrational Relaxation in Dense Vibrational Regions of S1 p-Difluorobenzene
T. A. Stone and C. S. Parmenter
J. Phys. Chem. A, 106, 938-944 (2002)
Observations of a Quantum Symmetry Restriction in the Rovibrationally Inelastic Scattering of Glyoxal
S. M. Clegg and C. S. Parmenter
J. Phys. Chem. A, 104, 10265-10270 (2000)
State-to-State Inelastic Scattering from S1 Glyoxal with the Rare Gas Series: Uniform Rotational vs. Changing Vibrational Channel Competition
S.M. Clegg, A.B. Burrill and C.S. Parmenter
J. Phys. Chem. A 102, 8477-8485 (1998)
Scaled Quantum Mechanical Study of Vibrational Force Field for p-difluorobenzene and p-fluorotoluene
A.A. Jarzecki, E.R. Davidson, Q.Ju and C.S. Parmenter
Int'l. J. of Quant. Chem. 72, 249-260 (1999)
Aligning Symmetric and Asymmetric Top Molecules via Single Photon Excitation
M.J. Weida and C.S. Parmenter
J. Chem. Phys. 107, 7138-7147 (1997)
Factors Controlling the Competition Among Rotational and Vibrational Energy Transfer Channels in Glyoxal
C.S. Parmenter, S.M. Clegg, D.J. Krajnovich and S.-P. Lu
Proceedings of National Academy of Sciences, USA (PNAS) 94, 8387-8392 (1997)
Crossed Beam Rovibrational Energy Transfer from S1 Glyoxal. 4. Reduced Mass Effects and An Overview of the Inelastic Scattering Characteristics from Four Initial Levels.
B.D. Gilbert, C.S. Parmenter and D.J. Krajnovich
J. Chem. Phys. 101, 7440-7450 (1994)
Acceleration of Intramolecular Vibrational Redistribution by Methyl Internal Rotation. A Chemical Timing Study of p-fluorotoluene and p-fluorotoluene!d3.
D.B. Moss and C.S. Parmenter
J. Chem. Phys. 98 6897-6905 (1993)