Martin L. Sage  Professor Emeritus Theoretical chemistry mlsage@syr.edu phone: 315-443-2713 / fax: 315-443-4070 Office: CST 3-014B Education: • A.B., 1955, Cornell University • Ph.D., 1959, Harvard University • Postdoctoral Fellow, 1959-1961, Brandeis University Honors & Awards: • National Science Foundation Fellowship, 1955-1957 • G.E. Foundation Fellowship, 1957-1959

Research Interests Molecular vibrations are oscillatory motions about some minimum in an electronic energy surface. Some chemical reactions involve rearrangement of atoms from one minimum on a single electronic energy surface to another minimum on that same surface. Here are two examples:
Conversion of HCN to metastable CNH requires motion of the H atom about the CH group.	Interconversion of the two molecules of malonaldehyde involves transfer of the hydrogen from the OH group to the oxygen of the aldehyde.
Professor Sage's research interests focus on large amplitude molecular vibrations. These vibrations are of importance in intramolecular energy transfer. Two examples of chemical significance are illustrated in the diagrams, which picture chemical reactions that take place on a single vibrational potential surface. The first is the interconversion of HCN and HNC which involves a 180-degree rotation of the CN group. HNC is a high-energy form which is metastable at low pressure. The second is malonaldehyde, which can interconvert between equivalent structures by a shift of the hydrogen of the aldehyde group to the ketone oxygen and interchanging single and double carbon-carbon bonds. Chemists use infrared and Raman spectroscopy to help characterize molecules. These techniques investigate vibrational motions near equilibrium geometry and are due to transitions where there are few vibrational levels. On the other hand, transitions to states with large-amplitude vibrations involve states in which there are many levels. Near equilibrium simple uncoupled normal modes are a reasonable approximation for vibrations. Away from equilibrium the picture is more complicated. Professor Sage has done much of his research on large-amplitude motions of hydrogen atoms in molecules. In these molecules progressions of X-H vibrations often are observed as weak transitions of an anharmonic oscillator. Some of the problems he is currently investigating include the effect of other vibrations on the observed potentials for X-H stretches, intramolecular interactions between non-bonded hydrogen atoms, and various potential forms for X-H bonds. He uses ab initio methods and has developed computer algebra techniques for dealing with large-amplitude and coupled vibrations. Selected Publications Sage, M.L. Isotope Effects in the High-Overtone Spectrum of C-H Stretches in HCN. Israel J. of Chem. 2004, 44, 37-40. Rong, Z.; Kjaergaard, H.G.; Sage, M.L. Comparison of the Morse and Deng-Fan Potentials for X-H bonds in Small Molecules. Mol. Phys. 2003, 101, 2285-2294. Daub, C.D.; Henry, B.R.; Sage, M.L.; Kjaergaard, H.G. Modeling and Calculation of Dipole Moment Functions for X-H bonds. Mol. Phys. 1999, 77, 1775-1781. Kjaergaard, H.G.; Henry, B.R.; Wei, H.; Lefebrve, S.; Carrington, Jr., T.; Mortensen, O. S.; Sage, M.L. Calculation of Vibrational Fundamental and Overtone Band Intensities in H2O. J. Chem. Phys. 1994, 100, 6228-6239. Sage, M.L. Applications of Computer Algebra to Molecular Spectroscopy. J. Mol. Struct. 1990, 223, 407-413. » View all Publications