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 ) are 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 ab 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.