Spectral and nonlinear optical studies of Propane-1, 3-diaminium nitrate

• Propane-1, 3-diaminium nitrate [C3H12N2] (NO3)2 (PDAN) is a new hybrid compound.
• The structure is built from alternating organic layers and inorganic, linked via hydrogen bond N–H⋯⋯O.
• Vibrational spectroscopy, thermal behavior and UV–vis are necessary for this work.
• The powder SHG efficiency of PDAN is 4.17 times greater than that of KDP.

Propane-1, 3-diaminium nitrate [C3H12N2] (NO3)2 (PDAN), an hybrid organic–inorganic nonlinear optical material combining an acentric octupolar moiety (nitrate) with a centrosymmetric organic molecule (Propane-1, 3-diaminium) was prepared by slow evaporation technique at room temperature from its aqueous solution. Good quality and well-developed crystals of size 0.133 mm×0.092 mm×0.078 mm were harvested from the mother solution. The grown single crystals were characterized for their spectral, thermal, linear and second order nonlinear optical properties. Solid-state 13C and 1H MAS-NMR spectroscopies are in agreement with the X-ray structure. The decomposition of the title compound is confirmed by the thermogravimetric analysis (TGA). The UV–visible absorption spectrum, show that PDAN is suitable for frequency doubling applications in a wide spectral range in the visible and near IR. The NLO response of the crystal was evaluated using a SHG powder technique, indicating an effective quadratic nonlinear coefficient two times higher than that of KDP in spite of the low hyperpolarizability of the nitrate ion and of the centrosymmetric character of the diaminium derivative.