Assisting the Effective Design of Polar Iodates with Early Transition-Metal Oxide Fluoride Anions

Hongwei Yu, Matthew L. Nisbet, Kenneth R Poeppelmeier

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24 Citations (Scopus)


Polar materials are of great technical interest but challenging to effectively synthesize. That is especially true for iodates, an important class of visible and mid-IR transparent nonlinear optical (NLO) materials. Aiming at developing a new design strategy for polar iodates, we successfully synthesized two sets of polymorphic early transition-metal (ETM) oxide-fluoride iodates, α- and β-Ba[VFO2(IO3)2] and α- and β-Ba2[VO2F2(IO3)2]IO3, based on the distinct structure-directing properties of oxide-fluoride anions. α- and β-Ba[VFO2(IO3)2] contain the trans-[VFO2(IO3)2]2- polyanion and crystallize in the nonpolar space groups Pbcn and P212121. In contrast, α- and β-Ba2[VO2F2(IO3)2]IO3 contain the cis-[VO2F2(IO3)2]3- λ-shaped polyanion and crystallize in the polar space groups Pna21 and P21, respectively. Detailed structural analyses show that the variable polar orientation of trans-[VFO2(IO3)2]2- polyanions is the main cause of the nonpolar structures in α- and β-Ba[VFO2(IO3)2]. However, the λ-shaped configuration of cis-[VO2F2(IO3)2]3- polyanions can effectively guarantee the polar structures. Further property measurements show that polar α- and β-Ba2[VO2F2(IO3)2]IO3 possess excellent NLO properties, including the large SHG responses (∼9 × KDP), wide visible and mid-IR transparent region (∼0.5-10.5 μm), and high thermal stability (up to 470 °C). Therefore, combining cis-directing oxide-fluoride anions and iodates is a viable strategy for the effective design of polar iodates.

Original languageEnglish
Pages (from-to)8868-8876
Number of pages9
JournalJournal of the American Chemical Society
Issue number28
Publication statusPublished - Jul 18 2018


ASJC Scopus subject areas

  • Catalysis
  • Chemistry(all)
  • Biochemistry
  • Colloid and Surface Chemistry

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