Noncentrosymmetric versus Centrosymmetric: Halogen Induced Variable Coordination Modes of Sn<sup>2+</sup> and Structural Transition in Sn<sub>3</sub>B<sub>3</sub>O<sub>7</sub>X (X = Cl and Br)
Jingyu Guo, Abudukadi Tudi, Xiaoquan Lu, Shujuan Han
Abstract
Two new borate halides, Sn3B3O7X (X = Cl and Br), were successfully synthesized via introducing Sn2+ with lone-pair and halogen into borate. Interestingly, halogen-induced variable coordination modes of Sn2+ and anion frameworks make them crystallize in different space groups, from noncentrosymmetric (Pna21) to centrosymmetric (Pbca). Sn3B3O7Cl possesses an SHG response of about 0.5 times that of KDP, while Sn3B3O7Br exhibits a large birefringence (0.123@1064 nm). The theoretical calculations were performed to elucidate the structure–property relationships.
Topics & Concepts
ChemistryHalogenCrystallographyLone pairBoronHalideSN2 reactionStereochemistryMoleculeInorganic chemistryAlkylOrganic chemistryCrystal Structures and PropertiesX-ray Diffraction in CrystallographySolid-state spectroscopy and crystallography