Spectral, thermal and optical properties of l-tryptophanium picrate: A nonlinear optical single crystal

- Charge-transfer (CT) complexes formed on the reaction of l-tryptophanium with picric acid have been studied.
- The infrared and 1H NMR spectra indicate a charge-transfer interaction associated with a proton migration from the acceptor.
- The strength of donor and acceptor groups and order of their stacking play important roles in determining the magnitude of nonlinear optical efficiency.