Ba13(BS3)6(SnS6): Synthesis, Crystal Structure, Electronic Structure, and Optical Property

A new zero-dimensional (0D) thioborate compound Ba-13(BS3)(6)(SnS6), the first one in the AE/B/Sn/Q (AE = alkali-earth metals; Q = S, Se, Te) family, has been synthesized by conventional high-temperature solid-state reaction. It crystallizes in the trigonal space group of R (3) over bar (No. 148) with a = b = 21.4634(6) angstrom, c = 8.3653 (5) angstrom, V = 3337.4 (2) angstrom(3), Z = 3, M-r = 2738.41, D-c = 4.088 g/cm(3), mu = 12.977 mm(-1), F (000) = 3576, the final R = 0.0208 and wR = 0.0505 with I > 2 sigma (I), 3.28<theta< 27.49 degrees, w = 1/[sigma(2)(F-o(2)) + (0.0253P)(2) + 0.0000P], where P = (F-o(2) + 2F(c)(2))/3, S = 1.051, (Delta rho)(max) = 0.639 and (Delta rho)(min) = -1.195 e/angstrom(3). The structure is constructed by discrete [BS3](3-) trigonal planes and isolated [SnS6](8-) octahedra with Ba2+ cations filled among them. The IR spectrum indicates the presence of lighter element boron. Its optical band gap shown by the UV-Vis-near-IR spectrum is about 2.69 eV, which agrees well with the electronic structure calculation.