Two similarly stoichiometric borate halides, NaBa4(AlB4O9)2Br3 and NaBa4(B5O9)2F2Cl, have been successfully designed and synthesized, and their structures were determined by single-crystal X-ray diffraction. Their crystal structures feature the [AlB4O9]∞ and [B5O9]∞ networks, respectively. NaBa4(AlB4O9)2Br3 is noncentrosymmetric and crystallizes in polar space group P42nm, while NaBa4(B5O9)2F2Cl is centrosymmetric and crystallizes in monoclinic space group P21/n. Powder second-harmonic generation (SHG) measurements reveal that NaBa4(AlB4O9)2Br3 has an optical nonlinearity comparable to that of KH2PO4 (KDP) and is type I phase-matchable. In addition, infrared and UV–Vis–NIR diffuse reflectance spectroscopy, as well as electronic band structure calculations, were performed on the reported materials.
Chinese Acad Sci, Key Lab Funct Mat & Devices Special Environm, Urumqi 830011, Peoples R China;Xinjiang Tech Inst Phys & Chem, Xinjiang Key Lab Elect Informat Mat & Devices, Urumqi 830011, Peoples R China;Univ Chinese Acad Sci, Beijing 100049, Peoples R China
Yu, HW ,Pan, SL ,Wu, HP ,et al. Effect of Rigid Units on the Symmetry of the Framework: Design and Synthesis of Centrosymmetric NaBa4(B5O9)(2)F2Cl and Noncentrosymmetric NaBa4(AlB4O9)(2)Br-3[J]. CRYSTAL GROWTH & DESIGN,2013,13(8):3514-3521.