Sn₃B₈O₁₅: A Ternary Tin(II) Borate with Flexible [B₈O₁₈]^12– Fundamental Building Block Formed by [B₇O₁₆]^11– and [BO₃]^3– Groups

Abstract

Owing to the tendency to form the glass state in growing crystals in the ternary tin­(II) borate system, hitherto, very few single crystals in ternary tin­(II) borate were reported. In this paper, a single crystal of Sn3B8O15 was obtained via a high temperature solution method in a closed system. The structure features a flexible fundamental building block [B8O18]12– constructed by one [BO3]3– unit and one [B7O16]11– group that contains three hexatomic rings, which further connect to compose a two-dimensional 2 ∞[B8O15] layer structure. The connection mode and flexibility of the three hexatomic B-O rings were analyzed, verifying the structural diversity of the B-O configuration. Moreover, the synthesis, crystal structure, and various characterizations were comprehensively presented. Also, theoretical calculations were employed to discuss structure-property relationships, and we use the real-space atom-cutting techniques to explain the origin of the birefringence of Sn3B8O15.

Pioneering Exploration in the Na–Lu–B–O System: Na3LuB8O15 with Polyborate Structure and Short UV Cutoff Edge

“…Borates have been widely studied in fields, such as nonlinear optics, lasers, loading catalysis, and adsorption separation, due to their diverse structures and stable physical and chemical makeup. − Up to now, a great deal of study and exploration into borate crystal materials has been done, and numerous materials with comprehensive performance borate crystals have been created; examples include KBBF, , LBO, BBO, CLBO, and so on. − According to research, the two hybridization modes that boron atoms often use to create coordination bonds with oxygen atoms in borate compounds lead to two B–O anion groups: the planar triangle shape of the sp 2 hybrid and the tetrahedral conformation of the sp 3 hybrid. , Both typically share the oxygen atom as a common vertex in borate crystals and create the multiple-dimensional skeleton of the crystal structure via condensation or multimerization, thereby increasing the variety of structures and material sources of borate compounds. − …”

Synthesis and characterization of a new rare earth borate nonlinear optical crystal K7PbLu2B15O30

“…The most prevalent ones are B 2 O 5 , B 3 O 6 , B 3 O 7 , B 4 O 9 , B 5 O 10 , and B 8 O 15 units. 23–30 The rich structure type of borates is very favorable to produce compounds with non-centrosymmetric structures. Moreover, borates can be used in the UV/DUV area due in large part to the significant electronegativity difference between the B and O elements, which is very beneficial for improving the transmission of crystals at short wavelengths and increasing the laser damage threshold.…”