| Cyclodextrins (CDs) are truncated cone-shaped cyclic oligosaccharides with a hydrophilic outer surface and a somewhat lipophilic central cavity. CD as host is able to include compound as guest that has suitable size, shape and polarity to form supramolecular inclusion compound. Inclusion compound has functions of solubilization, stabilization, antioxidant and slow release. Molybdenum (VI) complex has low solubility and heat-instability characters. Considering the functions of inclusion compound, in this paper Hydroxypropyl-β-Cyclodextrin as host, and molybdenum dioxobis (2,4-pentanedione) as guest, and host-guest complex have been prepared and studied by FT-IR, power X-ray diffraction, UV-vis absorption spectroscopy and electrochemistry methods. The effect factors and mechanism of inclusion are searched after.HP-p-CD is derivative which hydroxypropyls are linked in the CD's secondary hydroxyl groups under the condition of alkaline to result in dramatic improvements on CDs' solubility. HP-P-CD is fleetly and larger dissolved in water and its solubility can exceed 75g/100mL. And by constructing stereomodel, volume of cavity is expended by hydroxypropyls.MoO2(acac)2 aqueous solution presentes itself particularity with the variety of the concentration and the extension of time. In UV-vis spectrum, there are two absorption peaks. In max-absorption peak, the curve of concentration-absorbency isn't accordant with Lambert-Beer -law. While in the secondary absorption peak the curve is well linear. The aqua solution graduates blue solution when time passes by. Its absorbency increases obviously, however, the max-wavelength doesn't shift. So that, hypothesis of isomers is brought forward. Cis- and trans-form conformations each have α- and β- isomers. This hypothesis is regarded as existence by constructing stereomodel.In aqueous solution, a inclusion compound of MoO2(acac)2 with HP-P-CD has been first studied. The effects of temperature and time have been reviewed. The experimental results indicate that the ratio of HP-P-CD to MoO2(acac)2 in inclusion compound is 1:1 and MoO2(acac)2 molecule inside the hydrophobic cavity. This result is testified by spectra of IR and XRD and UV-vis. Solubility of MoO2(acac)2 in inclusion compound attains 20g/100mL, which is 20 times to no included MoO2(acac)2. When HP-P-CD adds to the MoO2(acac)2 aqueous solution, the absorbency decreases. Comparing with UV-vis spectra' change of inclusion... |
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