Acid Synthesis And Properties, - The Crown Ether Supramolecular Complexes

Because of their potential application in materials, life sciences, sorption clathration, catalysis, electric conductivity, magnetism, and photochemistry, et al, super-molecular complexes and polyoxometalates have received considerable attention recently. Moreover, super-molecules have presented special molecular recognition properties when acting as host molecules to interact with guest molecules. Polyoxometalates exhibit different polymerization and structures as the change of chemical circumstance. The combination of super-molecular complexes and polyoxometalates is currently opening up a new direction.We have synthesized a series of polyoxometalates super-molecules by crown ethers,such as DB18C6,DB24C8,N-Ph15C5,N-(p-ClPh)15C5,N-(p-CH₃Ph)15C5,and polyoxometalates with differert polymerization. Our works have also revealed that crown ethers with different radius choose different polyoxometalates with different polymerization and Mo/W composition.In this paper, we select DB18C6 as ligands, synthesize and characterize a series of polyoxometalates super-molecules. The synthesis procedures and crystal data of the complexes are as followed.1. Preparation of [Na(DB18C6)(CH₃CN)]₂Mo₆O₁₉. The crystal was obtained as follow: 0.8g of Na₂MoO₄ was dissolved in 30 ml CH3OH, adjusting its pH to 3.0 with hydrochloric acid, 0.1g DB18C6 was added, stirring about 20 hours, the solution was filtered, the residue was dried at room temperature, then transferred into a Teflon-Steel autoclave inside programmable electric furnace reactor with 20 ml CH3CN as solvent. Solvothermal reaction lasted for 20 hours at 423.15K, and then cooled to room temperature naturally. The complex was characterized by Elemental Analysis,IR, ¹HNMR, X-Ray. The crystal was crystallizes in monoclinic space group, P2₁/n. The complex consists of four basic uints, which are Na⁺,CH₃CN,DB18C6 and Mo₆O₁₉^2-. Sodium ion was located in the cavity of dibenzo-18-crown-6 with 6 Na-O bonds and coordinated with one of the terminal O atom of Mo₆O₁₉^2- and the N atom of CH3CN from two sides of the distorted DB18C6 plane respectively. The anion of Mo₆O₁₉^2- was in the middle of two [Na(DB18C6)(CH₃CN)]⁺, to form a sandwich super-molecular complex.2. Preparation of [Na(DB18C6)(CH₃CN)]₂W₆O₁₉. The crystal of complex2 was obtained similarly to complexl, just with instead Na₃WO₄ of Na₃MoO₄. The complex was characterized by Elemental Analysis,IR,¹HNMR,X-Ray. The crystal was crystallizes in monoclinic space group, P2₁/n. The complex consists of four basic uints, which are Na⁺,CH₃CN,DB18C6 and W₆O₁₉^2-. Sodium ion was located in the cavity of dibenzo-18-crown-6 with 6 Na-O bonds and coordinated with one of the terminal O atom of W₆O₁₉^2- and the N atom of CH₃CN from two sides of the distorted DB18C6 plane respectively. The anion of W₆O₁₉^2- was in the middle of two [Na(DB18C6)(CH3CN)]⁺, to form a sandwich super-molecular complex.3. Preparation of [Na(DB18C6)(CH₃CN)]₃ [α-PW₁₂O₄₀] The crystal of complex3 was...