New Alkaline-Earth Metal Fluoroiodates Exhibiting Large Birefringence and Short Ultraviolet Cutoff Edge with Highly Polarizable (IO₃F)^2– Units

Abstract

By the selective fluorination of IO 4 in iodates, SrI 2 O 5 F 2 (SIOF) and Ba(IO 2 F 2 ) 2 (BIOF) were synthesized successfully. They are the first reported cases of alkaline-earth metal fluoroiodates, and the (IO 3 F) 2− units in SIOF were discovered for the first time to the best of our knowledge. BIOF possesses the shortest UV cutoff edge (230 nm), and SIOF has the largest birefringence (cal. 0.203 at 532 nm) among the reported fluoroiodates. The highly polarizable (IO 3 F) 2− , with high polarizability anisotropy, induces a large birefringence in SIOF by theoretical calculation. This work will contribute to enlarge the structural diversity and provide a good choice for the material design in fluoroiodates.

[GaF(H2O)][IO3F]: a promising NLO material obtained by anisotropic polycation substitution

“…It is worth mentioning that [GaF(H 2 O)][IO 3 F] with uorinated IO 3 F group is also the rst trivalent metal uoroiodate, and hitherto only alkali-metal and alkaline-earth-metal uoroiodates have been reported. 58 The X-ray photoelectron spectroscopy (XPS) analysis results reveal that the molar ratio of Ga : I : O : F on the crystalline powder surface is approximately 1 : 1 : 4 : 2 (Fig. S5 †).…”

“…It is worth mentioning that [GaF(H 2 O)][IO 3 F] with fluorinated IO 3 F group is also the first trivalent metal fluoroiodate, and hitherto only alkali-metal and alkaline-earth-metal fluoroiodates have been reported. 58 …”

K3V2O3F4(IO3)3: a high-performance SHG crystal containing both five and six-coordinated V5+ cations

“…Of great importance are metal iodates which can exhibit high SHG response (d ij > 10 × KDP) or/and large birefringence (Δn > 0.15 @1064 nm). [13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29] Recently, two new effective routes to high performance metal iodate SHG crystals have been developed. One is using the 2D [Bi 2 O 2 ] 2+ layer and 3D [BiF 2 ] + cationic network for confined the iodate anions to be arranged in a favorable addictive fashion, which has successfully led to the discovery of BiO(IO 3 ) (12.5 × KDP) 20 and Bi(IO 3 )F 2 (11.5 × KDP, 0.22 @1064 nm) 21 .…”

“…One is using the 2D [Bi 2 O 2 ] 2+ layer and 3D [BiF 2 ] + cationic network for confined the iodate anions to be arranged in a favorable addictive fashion, which has successfully led to the discovery of BiO(IO 3 ) (12.5 × KDP) 20 and Bi(IO 3 )F 2 (11.5 × KDP, 0.22 @1064 nm) 21 . On the other hand, the condensation of iodate anions can also lead to the formation of polyiodates with outstanding SHG or birefringence properties, such as GdI 5 O 14 (15 × KDP) 29 and SrI 2 O 5 F 2 (0.180 @1064 nm) 26 .…”

From Ag2Zr(IO3)6 to LaZr(IO3)5F2: A Case of Constructing Wide‐band‐gap Birefringent Materials through Chemical Cosubstitution

“…So far, the introduction of other SOJT distortive cations (V 5+ , Nb 5+ , Bi 3+ , Pb 2+ , etc .) into metal iodates or condensation of IO 3 − and IO 4 3− anions to form polyiodate anions are the two major routes for exploring new metal iodates, which have led to the discovery of many metal iodates with excellent SHG performance [12–33] …”