Sn[B2O3F2]—The First Tin Fluorooxoborate as Possible NLO Material

다국어 초록 (Multilingual Abstract)

Herein, the crystal structure as well as second‐harmonic‐generation (SHG), thermal and spectroscopic properties of Sn[B2O3F2] (TFB = tin‐fluorooxo‐borate) are presented. TFB adopts a novel non‐centrosymmetric crystal structure, which is determined by single‐crystal X‐ray diffraction (XRD) (P31m, Z = 1, a = 4.5072(2) Å, c = 4.7624(3) Å) and comprises [B2O3F2]2− layers consisting solely of BO3F tetrahedra; the covalent BF bonds are unequivocally localized via solid‐state NMR spectroscopy as well as density functional theory (DFT) calculations. TFB is insensitive to air and moisture, shows a stronger SHG intensity than K[H2PO4] (KDP) and a bandgap of ≈5 eV. The thermal decomposition yields two new borate fluorides.
A novel perfectly non‐centrosymmetric structured material is born. Sn[B2O3F2] (TFB) is the very first tin fluorooxoborate comprising layers solely built up by BO3F tetrahedra with Sn(II) ions in‐between. Electron localization function calculations confirm the activity of the lone‐pair leading to a unique second‐harmonic‐generation active material with a higher intensity than K[H2PO4] and a bandgap of ≈5 eV.