Spectral, Optical, Mechanical and Thermal Studies of a New NLO Material

A new NLO crystal, glycinium para-toluenesulfonate (GPTS) is synthesized. The FT-IR study substantiated the formation of anion and cation by proton shift from para-toluenesulfonic acid (PTSA) to glycine resulting in adduct formation. Meyer’s index shows that GPTS belongs to soft category material. Vibrations due to all functional groups appeared in their respective regions confirming adduct formation. The presence of anion and cation is confirmed by 1H-NMR spectra. All the signals in 13C NMR spectrum correlate very well with the proposed structure with 1:1 molecular formula ratio. TGA/DTA analysis deduced the absence of water, presence of weak hydrogen bonding, higher melting point than PTSA and 1:1 molecular formula ratio. UV–Vis-DRS transmission studies show that the grown crystal has 80% optical transparency. The cut-off wavelength and band gap energy were found to be 265 nm and 4.22 eV respectively. The emission spectrum indicates that the sample exhibits green lighting emission sharply at 532 nm and it will be useful for fabricating green light emitting diodes. SHG efficiency is 1.5 times that of KDP. Thus the new material qualifies itself for possible use as NLO applications.