Two new polar potassium gold iodates, namely, K2Au(IO3)5 (Cmc21) and βâ KAu(IO3)4 (C2), have been synthesized and structurally characterized. Both compounds feature zeroâ dimensional polar [Au(IO3)4]â units composed of an AuO4 squareâ planar unit coordinated by four IO3â ions in a monodentate fashion. In βâ KAu(IO3)4, isolated [Au(IO3)4]â ions are separated by K+ ions, whereas in K2Au(IO3)5, isolated [Au(IO3)4]â ions and nonâ coordinated IO3â units are separated by K+ ions. Both compounds are thermally stable up to 400â °C and exhibit high transmittance in the NIR region (λ=800â 2500â nm) with measured optical band gaps of 2.65â eV for K2Au(IO3)5 and 2.75â eV for βâ KAu(IO3)4. Powder secondâ harmonic generation measurements by using λ=2.05â μm laser radiation indicate that K2Au(IO3)5 and βâ KAu(IO3)4 are both phaseâ matchable materials with strong SHG responses of approximately 1.0 and 1.3 times that of KTiOPO4, respectively. Theoretical calculations based on DFT methods confirm that such strong SHG responses originate from a synergistic effect of the AuO4 and IO3 units.Work together: Two new polar iodates, namely, K2Au(IO3)5 (Cmc21) and βâ KAu(IO3)4 (C2), with strong SHG effects (1.0 and 1.3 times that of KTiOPO4) have been discovered (see figure). Theoretical calculations confirm that such strong secondâ harmonic generation (SHG) responses originate from the synergistic effect of the AuO4 and IO3 units.
Peer Reviewed
https://deepblue.lib.umich.edu/bitstream/2027.42/137203/1/chem201504117-sup-0001-misc_information.pdf
https://deepblue.lib.umich.edu/bitstream/2027.42/137203/2/chem201504117.pdf