Ferrocene Derivatives With Polyoxometalates For The Synthesis And Properties Of Electron - Receptors In The Charge-transfer Salts

Polyoxometalates (POMs) are a unique large class of metal-oxygen clusters in structure and properties, and which have widespread application in many fields such as catalysis, magnetism, material science, environmental protection, medical science and so on. In recent years, POMs have been widely used as excellent electron-acceptors to react with electron-rich organic donors to form charge-transfer materials, which have attracted great attention due to their versatility and utility, such as electrical conductor, liquid crystal and nonlinear optical materials. This paper reports twelve novel charge-transfer salts (CTS) based on electron-rich ferrocene derivatives and POMs, in which the compounds (1)-(7) are isolated in crystalline state and other CTS are isolated in microcrystal or amorphous state.CTS in crystalline state:CTS based on CpFeCpCH2N(CH3)3I as the electron donor: [(C4H9)4N][CpFeCpCH2N(CH3)3][Mo6O19](1) [CpFeCpCH2N(CH3)3]4[W10O32]-CH3CN-2H2O(2) [CpFeCpCH2N(CH3)3]4[SMo12O40]-2CH3CN (3)CTS based on CpFeCpCH(CH3)PyCl as the electron donor: [CpFeCpCH(CH3)Py]2[Mo6O19] (4) [CpFeCpCH(CH3)Py]2[W6O19] (5) [CpFeCpCH(CH3)Py]4[W10O32] (6) [(C4H9)4 N]2[CpFeCpCH(CH3)Py]2[W10O32]·2CH3CN-2H20 (7)CTS in microcrystal or amorphous state:CTS'probable formation based on CpFeCpCH2N(CH3)3I as the electron donor: [CpFeCpCH(CH3)Py]4[SiMo12O40](8) [CpFeCpCH(CH3)Py]4[GeMo12O40](9)CTS'probable formation based on C2H5CpFeCpC2H5 as the electron donor: [C2H5CpFeCpC2H5]4[SiMo12O40](10) [C2H5CpFeCpC2H5]3[PMo12040] (11) [C2H5CpFeCpC2H5]3[AsMo12040](12)The new compounds were characterized by IR, Elemental analysis, and X-ray single-crystal analysis to determine their compositions and structures, as well as UV-vis spectrum, fluorescence, CV and so on to reveal their properties.Single-crystal structures of the compounds (1)-(7) showed that there are complex interactions between the ferrocene-type electron donors and the polyanions, and the donors with each other, such as Van der Waals'force, hydrogen bond andπ…πstacking interaction. The comparation between the UV-vis spectra in solution and solid state of the compounds showed there were new charge-transfer absorption bands in solid state, but not in solution, which indicates that the compounds are almost entirely dissociated in a diluted solution. The fluorescence signals of the charge-transfer salts were obviously different from those of the corresponding POMs, and the shapes, intensities and the positions of fluorescence spectra of the CTSs are obviously not the simple supraposition of the starting materials, which suggests the occurrence of an efficient charge transfer process from the ferrocenyl donor to POM acceptors.The last chapter reported a new sandwich polyoxometalate based on Keggin-type monolacunary polyoxotungstoborate anion, K14[Zr(a-BW11O39)2]·19H2O (13), which was fully characterized. Up to now the study on vacant Keggin fragments with a boron atom as the center hetero atom is relatively rare.