Isomeric Cd(NH4)2(PO3F)2·2H2O: Solution concentration-driven elimination of antiparallel dipole-dipole interaction generating an SHG β phase

Na4[B6O9 (OH)3](H2O) Cl: A Deep-Ultraviolet Transparent Nonlinear Optical Borate Chloride with {[B6O9 (OH)3]3–}∞ Chains

“…As for the current study strategies for designing DUV NLO material, adopting inorganic anion groups including BO 3 3– , B 3 O 6 3– , SiO 4 4– , PO 4 3– , and SO 4 2– are fruitful routes, which can be proved by many DUV NLO materials including Li 4 Sr­(BO 3 ) 2 (1.2 × KDP), Sr 2 Be 2 B 2 O 7 1 (3.8 × KDP), Cs 2 Al 2 (B 3 O 6 ) 2 O (0.5 × KDP), Li 2 BaSiO 4 (2.8 × KDP), Li 3 AlSiO 5 (0.8 × KDP), KMg­(H 2 O) PO 4 (1.14 × KDP), RbBa 2 (PO 3 ) 5 (1.4 × KDP), NH 4 NaLi 2 (SO 4 ) 2 (1.1 × KDP), (NH 4 ) 2 Na 3 Li 9 (SO 4 ) 7 (0.5 × KDP). Furtherly, combining halogen anions (F – , Cl – , Br – ), which is helpful to widen the transmission regions, with the above anion groups is also an effective method to exploit novel DUV NLO compounds, such as Cd­(NH 4 ) 2 (PO 3 F) 2 ·2H 2 O, K 3 Sc 3 (PO 4 )­(PO 3 F) 2 F 5 , NaRbB 3 O 4 F 3 , and Ba 3 P 3 O 10 X (X = Cl, Br). − DUV borate crystal materials have become a hot topic in the field of inorganic crystalline materials because of their varied structures and potential applications in nonlinear optics and birefringent fields. − It is noteworthy that many borates containing halogen anions, especially the F – anions, that exhibit DUV transmission and even produce good second harmonic generation (SHG) effects have been obtained in recent years, such as AB 4 O 6 F (A = NH 4 , Na, Rb, Cs, K/Cs, Rb/Cs; ABF), MB 5 O 7 F 3 (M = Ca, Sr; MBF), K 3 M 3 Li 2 Al 4 B 6 O 20 F (M = Sr or Ba), Sc 2 F 2 (B 2 O 5 ). − It follows that the borates containing halogen anions have been a rich source for DUV NLO crystals. However, most of the attention has been drawn to borate fluorides or fluoroborates, and the borate chlorides or bromides need more research.…”