Cs₂VOF₄(IO₂F₂): Rationally designing a noncentrosymmetric early-transition-metal fluoroiodate

Abstract

F-containing early-transition-metal (ETM) iodates are an interesting materials class for the exploration of nonlinear optical (NLO) crystals. However, their rational structural design remains a great challenge due to the poor...

Polar Bismuth Selenite Iodate Oxide BiSeIO6 with Three Types of Lone Pair Cations in One Structure

“…The selenium and iodine atoms both have the typical Se/I-O 3 pyramidal environments coordinated with three oxygen atoms along with the lone pair electrons at the top of the pyramids. The bond lengths of Se/I–O fall into the ranges of 1.779–1.799 and 1.724–1.758 Å for the Se/I(1) and Se/I(2) centers, respectively, which are consistent with the reported ones. − The average Se/I(1)–O distance is 1.786 Å, which is (Se: 0.64; I: 0.58, O: 1.22). The Se/I(1)–O distance is slightly larger than that of Se/I(2)–O because the occupancy ratio of iodine is larger on the Se/I(1) site than on the Se/I(2) site.…”

C(NH2)3(I3O8)(HI3O8)(H2I2O6)(HIO3)4·3H2O: An Unprecedented Asymmetric Guanidinium Polyiodate with a Strong Second-Harmonic-Generation Response and a Wide Band Gap

“…27 Similarly, Yu et al successfully synthesized Cs 2 VOF 4 (IO 2 F 2 ) with a considerable band gap (4.82 eV) by substituting the I−O bonds by I−F bonds. 28 Moreover, it has been proven that the band gap of the obtained compounds can also be improved by introducing a πconjugated guanidinium [C(NH 2 ) 3 + , GU] group. 29 When the C(NH 2 ) 3 + cation replaces Ba 2+ , the band gap increases significantly from 3.06 eV of Ba(MoO 2 ) 30,31 This is due to the fact that the strong C−N covalent bonds in the C(NH 2 ) 3 + group induce a wide optical transmission range and the planar π-conjugated molecular orbitals contribute to the generation of large SHG coefficients.…”

“…For example, when the Bi–O bonds are replaced by Bi–F bonds, the band gap is increased from 3.3 eV of BiO(IO 3 ) to 3.97 eV of Bi(IO 3 )F 2 . Similarly, Yu et al successfully synthesized Cs 2 VOF 4 (IO 2 F 2 ) with a considerable band gap (4.82 eV) by substituting the I–O bonds by I–F bonds . Moreover, it has been proven that the band gap of the obtained compounds can also be improved by introducing a π-conjugated guanidinium [C(NH 2 ) 3 + , GU] group .…”

MIO3F (M = Co and Ni): Magnetic Iodate Fluorides with Zigzag Chains

“…The iodate group has been widely used for achieving nonlinear optical materials due to its stereochemically active lone pair effect, such as in Cs 2 I 4 O 11 , A 2 Ti­(IO 3 ) 6 (A = Li, Na, K, Rb, Cs, and Tl), BaNbO­(IO 3 ) 5 , LiM­(IO 3 ) 3 (M = Zn and Cd), KVO 2 (IO 3 ) 2 (H 2 O), K­(VO) 2 O 2 (IO 3 ) 3 , K 4 [VO­(IO 3 ) 5 ] 2 (HIO 3 )­(H 2 O) 2 ·H 2 O, Cs 2 VOF 4 IO 2 F 2 , β-Sc­(IO 3 ) 3 , and [C­(NH 2 ) 3 ]­Mo 2 O 5 (IO 3 ) 4 ·2H 2 O . Meanwhile, the combination of multiple anions is an effective method to enhance performance or create novel properties of functional materials .…”