New Aspects on the Origin of Color in the Solid State. Coherently Shifting of the Protons in Violurate Crystals

The self-assembly and properties of six novel violurates with organic counterions, that is, cyclohexylammonium violurate (1), piperidinium violurate 2.5 hydrate (2), tetrahydroisoquinolinium violurate monohydrate (3), quinuclidinium violurate tetrahydrate (4), pyridinium violurate (5), and 3-aminopyridinium violurate (6) arc reported. Compounds 1-6 were synthesized and characterized in detail by means of single crystal X-ray diffraction, solution and solid-state UV/vis spectroscopy, linear-polarized infrared (IR-LD) spectroscopy of oriented colloids in a nematic host, mass spectrometry, and thermal methods. Quantum chemical A initio and density functional theory (DFT) calculations were performed with a view to understanding the optical properties of the studied species. New phenomenon of the origin of the color in the solid state is observed and elucidated.