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A novel ternary rare-earth sulfide, CsYb_7S_(11), has been successfully synthesized by high-temperature solid-state reaction of an elemental mixture with modified Cs Cl flux. The single-crystal X-ray diffraction data reveal its orthorhombic symmetry in space group Cmca(no. 64) with a = 15.271(3), b = 13.414(2), c = 18.869(3) ?, V = 3865.2(2) ?~3, Z = 8, M_r = 1696.85, D_c = 5.832 g/cm~3, μ = 36.538 mm~(-1), F(000) = 5768, the final R = 0.0225 and w R = 0.0517 for 2258 observed reflections with I > 2σ(I), 2.67<θ<27.48o, w = 1/[σ~2(Fo~2) +(0.0443 P)2 + 8.7453 P], where P =(Fo~2 + 2Fc~2)/3, S = 1.036,(Δρ)max = 1.609 and(Δρ)min = –1.922. The remarkable structural feature is the dual tricapped Cs_2@S_(18) cube closed cavities far apart within the three-dimensional [Yb_7S_(11)]-covalent bonding matrix. Magnetic susceptibility measurements show that the title compound exhibits temperature-dependent(50~300 K) para-magnetism and obey the Curie-Weiss law. Moreover, the optical gap of 2.03 eV for CsYb_7S_(11) was deduced from the UV/Vis reflectance spectroscopy and DFT study indicates an indirect band gap with an electronic transfer excitation of S-3p to Yb-5d orbital.
A novel ternary rare-earth sulfide, CsYb_7S_ (11), has been synthesized synthetically by high-temperature solid-state reaction of an elemental mixture with modified CsCl flux. The single-crystal X-ray diffraction data reveal its orthorhombic symmetry in space group Cmca (no. 64) with a = 15.271 (3), b = 13.414 (2), c = 18.869 (3) ?, V = 3865.2 (2)? ~ 3, Z = 8, M_r = 1696.85, D_c = The final R = 0.0225 and w R = 0.0517 for 2258 were reflections with I> 2σ (I), 2.67 <θ <5.8σ, Where P = (Fo ~ 2 + 2Fc ~ 2) / 3, S = 1.036, (Δρ) max = 27.48o, w = 1 / [σ ~ 2 (Fo ~ 2) + (0.0443 P) 2 + 8.7453 P] = 1.609 and (Δρ) min = -1.922. The remarkable structural feature is the dual tricapped Cs_2 @ S_ (18) cube closed cavities far apart within the three-dimensional [Yb_7S_ (11)] - covalent bonding matrix. that the title compound exhibits temperature-dependent (50-300 K) para-magnetism and obey the Curie-Weiss law. Moreover, the optical gap of 2 .03 eV for CsYb_7S_ (11) was deduced from the UV / Vis reflectance spectroscopy and DFT study indicates an indirect band gap with an electronic transfer excitation of S-3p to Yb-5d orbital.