Raman Spectroscopic Evidence for Two Conformations of Uncomplexed Valinomycin in the Solid State
Kenneth J. Rothschild 1,
Irvin M. Asher 2,
Evangelos Anastassakis 3, and
H. Eugene Stanley 4
1 Department of Physics and Harvard-M.I.T. Program in Health Sciences and Technology, Massachusetts Institute of Technology, Cambridge 02139
2 Physics Department, Northeastern University, Boston, Massachusetts 02115, and Department of Physics and Harvard-M.I.T. Program in Health Sciences and Technology, Massachusetts Institute of Technology
3 Physics Department, Northeastern University
4 Department of Physics and Harvard-M.I.T. Program in Health Sciences and Technology, Massachusetts Institute of Technology
Raman spectroscopy is applied for the first time to elucidate the different conformations of the carrier transport molecule, valinomycin. Splitting of the ester and amide carbonyl stretch vibrations is observed in the Raman spectrum of crystals of valinomycin grown from both n-octane and acetone. These observations support the contention that some ester carbonyl groups are intramolecularly hydrogen bonded. The Raman spectrum of valinomycin grown from o-dichlorobenzene does not display this feature.
