Syntheses, Characterization, and Optical Properties of Centrosymmetric Ba₃(BS₃)1.5(MS₃)0.5 and Noncentrosymmetric Ba₃(BQ₃)(SbQ₃)

The most advanced UV-vis and IR NLO materials are usually borates and chalcogenides, respectively. But thioborates, especially thio-borometalates, are extremely rare. Here, four new such compounds are discovered by solid state reactions representing 0D structures constructed by isolated BQ3 trigonal planes and discrete MQ3 pyramids with Ba(2+) cations filling among them, centrosymmetric monoclinic P21/c Ba3(BS3)1.5(MS3)0.5 (M = Sb, Bi) 1, 2 with a = 12.9255(9), 12.946(2) Å; b = 21.139(2), 21.170(2)Å; c = 8.4194(6), 8.4207(8) Å; β = 101.739(5), 101.688(7)°; V = 2252.3(3), 2259.9(3) Å(3) and noncentrosymmetric hexagonal P6̅2m Ba3(BQ3)(SbQ3) (Q = S, Se) 3, 4 with a = b = 17.0560(9), 17.720(4) Å; c = 10.9040(9), 11.251(3) Å; V = 2747.1(3), 3060(2) Å(3). 3 exhibits the strongest SHG among thioborates that is about three times that of the benchmark AgGaS2 at 2.05 μm. 1 and 3 also show an interesting structure relationship correlated to the size mismatching of the anionic building units that can be controlled by the experimental loading ratio of B:Sb. Syntheses, structure characterizations, and electronic structures based on the density functional theory calculations are reported.