THE SPECTRA OF $\alpha, \alpha, \alpha$-TRICHLOROACETAMIDE/$AROMATIC \pi$- COMPLEXES IN THE N-H STRETCHING $REGION^{\ast}$

$^{\ast}$ This work was sponsored in part by the National Science Foundation. $^{\S}$ Present address: U.S. Naval Research Laboratory, Washington, D. C. 20390. $^{\dag}$ Present address: Regional Research Laboratory, Hyderabad-9, A. P., India. $^{\ddag}$ Present address: National Physical Laboratory, Basic Physics Division, Teddington, Middlesex, United Kingdom.Author Institution: Institute for Molecular Physics, University of MarylandThe spectrum of $\alpha, \alpha, \alpha$-trichloroacetamide (TCA) was observed previously in this laboratory in the course of an investigation of the effect of high pressures on the optical absorption spectra of amides and amines in solution. A number of additional bands appeared in the N-H stretching region of the spectrum of TCA in mixed solvents containing an aromatic electron-donor as one component. In the present investigation, the spectra of TCA and of several amides whose cis-trans equilibria are known have been studied in a series of mixed solvents. The new bands have now been assigned to either bonded or unbonded N-H stretching vibrations in various complex species