Hg₃O₂(NO₃)F: a mercury nitrate oxyfluoride with an unprecedented [(Hg₃O₂F)⁺]_∞cationic framework and excellent optical anisotropy

Abstract

Combining multiple anions to design compounds with novel structures and excellent optical properties has become a hot research field. In this paper, a novel nitrate oxyfluoride, Hg3O2(NO3)F, has been obtained....

From ZnF2 to ZnF2(H2O)4: Partial Substitution Achieves Structural Transformation and Nonlinear Optical Activity while Keeping Short Ultraviolet Cutoff Edge

“…Here, we chose ZnF 2 as the parent compound. On the one hand, fluorides tend to have a large band gap, corresponding to a low UV cutoff wavelength due to the largest electronegativity of F atom. − On the other hand, the polyhedron of Zn 2+ with d 10 electron configuration is prone to second-order Jahn–Taylor distortion, which is more likely to form an NCS structure, and then produce the SHG effect. − In addition, based on previous reports, we also know that Zn-containing oxyhalides mostly reach short UV cutoff edges. Such compounds as RbZn 2 BO 3 Br 2 (214 nm), KZn 2 BO 3 Cl 2 (194 nm), and NH 4 Zn 2 BO 3 Cl 2 (190 nm) were reported to confirm this idea.…”

Hg16O12(NO3)6F2(H2O): A Mercury-Rich Nitrate Oxyfluoride with Diverse Triple-Coordinated Mercury-Based Units That Exhibits an Unparalleled [(Hg16O12F2(H2O))6+]∞ Cationic Framework and a Large Birefringence

“…The results indicate that Hg 16 O 12 (NO 3 ) 6 F 2 (H 2 O) exhibits a distinct chemical composition. This finding suggests that adjusting the F/O ratio is an effective approach to obtaining innovative structures. − …”

“…Under the guidance of this idea, we try to adjust the synthesis on the basis of the recently studied compound Hg 3 O 2 (NO 3 )F and find that the compound Hg 16 O 12 (NO 3 ) 6 F 2 (H 2 O) has novel HgO 2 F and HgO 2 (H 2 O) structural units, structural frameworks, and good optical properties . Consequently, we obtain a new mercury nitrate oxyfluoride, Hg 16 O 12 (NO 3 ) 6 F 2 (H 2 O), by a hydrothermal reaction experiment at 200 °C.…”

“…The optical band gap of the Hg 16 O 12 (NO 3 ) 6 F 2 (H 2 O) polycrystalline powder sample was determined to be 2.5 eV using UV–vis–near-IR (NIR) diffuse-reflectance spectroscopy, which is lower than those of the nitrate halide Cs 2 Pb 2 (NO 3 ) 2 Br 2 (3.01 eV) and CsHgNO 3 Cl 2 (3.1 eV), while higher than that of Hg 3 O 2 (NO 3 )F (2.19 eV) (Figure ). ,, We can improve the band gap by introducing the alkali metal, alkaline-earth alkaline, or increasing the proportion of F atoms, as well as adjusting the proportions of F – and NO 3 – anions. − In the IR spectrum (Figure S7), the peaks at 3430, 1737, and 1563 cm –1 indicate the existence of H 2 O molecules, which contain the stretching and vibration of the O–H bonds. The intense band at 1398 cm –1 is attributable to the N–O stretching vibrations in the NO 3 triangles, and the band at 1263 cm –1 is ascribed to the nonplanar bending vibrations of the NO 3 planar groups.…”

From Pb6(HPO3)(H2PO3)Cl9 to Pb6(HPO3)2Br8(H2O)·H2O: Halogen Regulation to Achieve Inorganic Metal Phosphite Halide Nonlinear Optical Material with Unprecedented Pb-Centered Polyhedral Units

“…As an important branch of nonlinear optical crystals, frequency-doubled crystal materials have been widely studied in the past decades. Researchers have found many excellent NLO crystal materials, such as AgGaS 2 (AGS), ZnGeP 2 (ZGP), LiB 3 O 5 (LBO), KH 2 PO 4 (KDP), KTiOPO 4 (KTP), KBe 2 BO 3 F 2 (KBBF), and β-BaB 2 O 4 (β-BBO). − After decades of research, it is still a hot research direction to explore new crystalline materials with excellent NLO properties and analyze their structure–activity relationships. − …”