A supra-cubane-like Mo/S/Cu cluster: Cation-directed synthesis, crystal structure and nonlinear optical property

Directed by potassium–crownether host–guest cation, a unique octameric eicosanuclear heterothiometallic Mo/S/Cu cluster [K(dibenzo-18-crown-6)(DMF)2]4[Mo8S32Cu12] (1) was synthesized by the reaction of (NH4)2MoS4, CuI, KI, dibenzo-18-crown-6 in DMF solution. 1 was characterized by elemental analysis, IR, thermogravimetric analysis, X-ray powder and single crystal diffractions. 1 crystallizes in the tetragonal space group I41cd. The anionic octameric eicosanuclear [Mo8S32Cu12]4− cluster exhibits a supra-cubane-like skeleton, fabricated by four nest-shaped clusters [Mo(μ1-S)(μ3-S)3Cu3]+ and four flywheel-shaped clusters [Mo(μ2-S)3(μ4-S)Cu3]+ linking together through shared Cu atoms. The cation [K(dibenzo-18-crown-6)(DMF)2]+ of 1 exhibits the host–guest configuration, where K+ is embedded in the center of dibenzo-18-crown-6. Furthermore, Z-scan studies (532 nm, 21 ps pulses) reveal that 1 possesses effective third-order nonlinear optical (NLO) properties.

Graphical abstractA unique anionic octameric supra-cubane-like heterothiometallic Mo/S/Cu cluster was synthesized in the presence of potassium–crownether host–guest cation. Furthermore, Z-scan studies reveal that this cluster possesses effective third-order nonlinear optical properties.Figure optionsDownload full-size imageDownload as PowerPoint slide