CdB10O14(OH)4·H2O with an unprecedented decaborate fundamental building block

作者：Yang D.^*; Jing Y.^*; Zhang Y.^*; Liu X.^*; Lin Z.^*; Cong R.; Gao W.; Yang T.^*

来源：Materials Research Bulletin, 2013, 48(2): 270-276.

• A. Inorganic compound, B. Chemical synthesis, C. X-ray diffraction, D. Crystal structure

CdB10O14(OH)4·H2O has been synthesized under boric acid flux condition and characterized by single-crystal X-ray diffraction, infrared spectra, and UV-vis reflectance spectroscopy. It crystallizes in the monoclinic space group P21/n with a = 7.7277(8), b = 18.95(2), c = 9.8616(10) Å, β= 91.454(1)°, V = 1443.7(3) Å. The structure consists of [B 10O16(OH)4] layers of 9-membered borate rings enclosing Cd2+ cations. Adjacent borate layers are interconnected via hydrogen bonding to form a 3D network. It possesses an unprecedented decaborate fundamental building block B10O20. The structure details are discussed together with Sr[B6O9(OH) 2]·3H2O, Pb[B8O11(OH) 4], Pr[B8O11(OH)5], and Nd[B 9O13(OH)4]·H2O, which have correlated FBBs. The band structure calculations show its direct energy band gap of ∼4.68 eV, in consistent with the estimated value (4.77 eV) from UV-vis. In addition, dielectric constants and refractive indexes are also calculated.