Synthesis, Characterization, and Theoretical Studies of (Pb₄O)Pb₂B₆O₁₄: A New Lead(II) Borate with Isolated Oxygen-Centered Pb₄O Tetrahedra and Large Second Harmonic Generation Response

Abstract

A new lead(II) borate, (Pb 4 O)Pb 2 B 6 O 14 , has been synthesized by low-temperature hydrothermal method. It crystallizes in the noncentrosymmetric polar space group P1 and structurally features a three-dimensional framework composed of paralleled spiral B 6 O 14 chains connected by the Pb cations and isolated oxygen-centered Pb 4 O tetrahedra. It exhibits a phase-matching powder second harmonic generation (SHG) effect of about 3.5 times that of KH 2 PO 4 (KDP) at the 1064 nm fundamental wavelength. It also has optical band gap of 3.3 eV and high thermal stability up to 480 °C, which make it a promising candidate for nonlinear optical (NLO) material. In addition, electronic structure and NLO property are studied by the first-principles method, and the calculated NLO coefficients are consistent with the experimental observations. The important contributions of Pb 4 O tetrahedra and the borate groups to the SHG response have been identified by the SHG-density method.

α-, β-Pb4B2O7 and α-, β-Pb4B6O13: Polymorphism drives changes in structure and performance

“…The IR spectra of α-Pb 4 B 2 O 7 and β-Pb 4 B 6 O 13 are shown in Fig. S4 ) were both observed [60,61]. This result also matches pretty well with the crystal structure analysis.…”

KSnI3 ⋅ H2O: A New Compound with One‐Dimensional SnI3 Chains of Pyramidal SnI5 Polyhedra

“…Besides, introducing some anions, such as F − , Cl − , Br − , I − , and OH − into the crystals can harmonize the ratio of anions and cations to make the crystal structures more flexible and variable. Guided by the above ideas, some new materials with special structures and diverse applications have been produced, such as Bi 2 ZnOB 2 O 6 , [36] Cd 4 BiO(BO 3 ) 3 , [37] KBe 2 BO 3 F 2 , [38] MB 2 O 3 F 2 (M=Sn, Pb), [39] CsZn 4 (BO 3 )(PO 4 ) 2 , [40] AB 4 O 6 F (A=NH 4 , Na, Cs, Rb), [41] and so on [42–48] . Under the guidance of the above ideas, we focus on the Sn(II)‐I system with the hope to realize the synthesis of new materials with novel structures and to examine the birefringent properties.…”

“…These values are consistent with hydrogen bonds in other inorganic crystals. [48] Bond valence sums for all atoms were calculated with the following formula: Table S4 in the Supporting Information (K, 1.081; Sn, 2.197; I(1), 1.29; I(2), 0.932; I(3), 0.767; O, 1.82; H, 0.94), which indicate that the bond valence of each element in the title compound is reasonable.…”

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

“…Among inorganic borates synthesized and characterized over the past decades, some lead(II) borates show comprehensive applications. These features are associated with the highly asymmetric stereochemistry typical for a lead(II) atom due to the stereoactivity of the 6s 2 lone pair (Zhang et al, 2016;Mutailipu et al, 2016). Accordingly, numerous studies have been devoted to this family of compounds.…”