Synthesis and optical properties of the first lead borate bromide with isolated BO₃groups: Pb₂Ba₃(BO₃)₃Br

Abstract

Single crystals of a new compound Pb2Ba3(BO3)3Br have been grown by a spontaneous crystallization method. They crystallize in the noncentrosymmetric orthorhombic space group C2221 with isolated BO3 triangles and distorted PbO polyhedra. UV-Vis-NIR diffused reflectance spectroscopy measurements indicate that the absorption edge is at 326 nm. Second-harmonic generation (SHG) measurements using 1064 nm radiation show that Pb2Ba3(BO3)3Br exhibits relative large NLO response about 3.1× that of KH2PO4 (KDP) and is type I phase-matchable. First-principles electronic structure calculations show that the isolated BO3 groups and PbO4 polyhedra play an important role in the total SHG response.

Two Lanthanide Borate Chlorides LnB4O6(OH)2Cl (Ln = La, Ce) with Wide Ultraviolet Transmission Windows and Large Second-Harmonic Generation Responses

“…For example, commercial UV NLO materials β-BaB 2 O 4 (BBO) possess [B 3 O 6 ] 3– units, while LiB 3 O 5 (LBO) and CsLiB 6 O 10 (CLBO) feature [B 3 O 7 ] 5– blocks. Particularly, borate halide is an arresting branch, because such compounds more likely crystallize in non-centrosymmetric (NCS, which is the prerequisite for NLO optical materials) space group than other inorganic compounds, and deformed MO m X n (M is metal cation and X is halogen anion) polyhedra are conducive to enhance the SHG response. − In recent decades, many halide-contained borates NLO materials with good SHG responses spring up, such as AB 4 O 6 F (A = NH 4 , Na, Rb, Cs), − Pb 2 BO 3 Cl, Ba 3 B 6 O 11 F 2 , Ba 4 B 11 O 20 F, SrB 5 O 7 F 3 , K 3 B 6 O 10 X (X = Cl, Br), , Pb 2 Ba 3 (BO 3 ) 3 X (X = Cl, Br), , Pb 2 BO 3 I, and Pb 2 B 5 O 9 I …”

“…Particularly, borate halide is an arresting branch, because such compounds more likely crystallize in non-centrosymmetric (NCS, which is the prerequisite for NLO optical materials) space group than other inorganic compounds, and deformed MO m X n (M is metal cation and X is halogen anion) polyhedra are conducive to enhance the SHG response. 25−28 In recent decades, many halide-contained borates NLO materials with good SHG responses spring up, such as AB 4 O 6 F (A = NH 4 , Na, Rb, Cs), 29−32 Pb 2 BO 3 Cl, 33 Ba 3 B 6 O 11 F 2 , 34 Ba 4 B 11 O 20 F, 27 SrB 5 O 7 F 3 , 35 K 3 B 6 O 10 X (X = Cl, Br), 36,37 Pb 2 Ba 3 (BO 3 ) 3 X (X = Cl, Br), 38,39 Pb 2 BO 3 I, 25 and Pb 2 B 5 O 9 I. 28 It is worth noting that cations which are free of d−d, f−f, or f−d electronic transitions are preferred since they could facilitate transparency attaining UV or deep-UV spectral ranges.…”

K9[B4O5(OH)4]3(CO3)X·7H2O (X = Cl, Br): Syntheses, Characterizations, and Theoretical Studies of Noncentrosymmetric Halogen Borate–Carbonates with Short UV Cutoff Edges

“…In the structures of the isomorphic compounds of borate chlorides and bromides except Na 3 B 4 O 7 X (X = Cl, Br), the cations are bonded to the O atoms to form a 3D network structure, and the Cl or Br atom is filled in a closed channel formed by cationic polyhedra (Table ). For example, in the structures of Pb 2 Ba 3 (BO 3 ) 3 X (X = Cl, Br), , the Ba atoms are bonded to the O atoms to form the Ba 6 O 28 groups, and the Ba 6 O 28 groups connect via edge-sharing to build a four-membered-ring (4-MR) tunnel with the Cl or Br atoms located (Figure a). When the Cl or Br atoms are substituted by the I atoms, the larger I atoms reside in the 4-MR tunnels, it would be difficult to keep the structure stable.…”

Crystal structure of the solid solution Ba8.35Pb0.65(B3O6)6

“…Accordingly, numerous studies have been devoted to this family of compounds. Some lead borates are particularly attractive because of their high second-harmonic generation (SHG) response (Wu et al, 2012;Dong et al, 2015;Jing et al, 2015) or large birefringence (Liu et al, 2015). In this communication, we report on the synthesis and crystal structure of the solid solution Ba 8.35 Pb 0.65 (B 3 O 6 ) 6 .…”