New molecular crystals with nonlinear optical properties: 3aminophenol-H3PO4 and 4-aminophenol-H3PO4

The crystal structures of the 3-aminophenol-H3PO4 (3-amphph) and 4aminophenol-H3PO4 (4-amphph) complexes were determined at 100 K. They both belong to the P212121 space group of the orthorhombic system with Z=4. The lattice parameters for the 3-amphph crystal are a=4.493(2) ?, b=9.750(3) ? and c=18.328(4) ? and those for the 4-amphph crystal are a=6.116(2) ?, b=7.496(2) ? and c=18.739(4) ?. The SHG powder efficiencies relative to KDP were 0.86 for 3-amphph and 0.50 for 4amphph, measured at 1064 nm using the Kurtz-Perry method. The infrared powder spectra of both complexes were obtained and the hydrogen bond vibrations are discussed.