SYNTHESIS AND CHARACTERIZATION OF MANGANESE-BASED FERROCENYL COORDINATION POLYMER MICROSPHERES

Abstract

A series of manganese-based ferrocenyl coordination polymer microspheres were prepared by solvothermal reactions,the influence of reaction time and reagent concentration on the morphology and diameters of microspheres was investigated systematically,and the morphology,diameters and crystal structure of manganese-based ferrocenyl coordination polymer microspheres were characterized by scanning electron microscopy(SEM),transmission electron microscopy(TEM),powder X-ray diffraction(PXRD),energy dispersive X-ray spectrometry(EDX) and Fourier-transform infrared spectroscopy(FT-IR).By adjusting the reaction time from 8 h,12 h to 24 h,the diameters of microspheres increased from 4 μm to 9.4 μm;on the contrary,the increase of reagent concentration decreased the size of particles from 11.4 μm to 9.4 μm at the tested range,and,at the same time,spheres were transformed from smooth spherical structures into core-shell structures.PXRD showed that manganese-based ferrocenyl coordination polymers crystallized into sandwich layered crystal structure with the possible formula of Mn4(OH)4(OOCC5H4FeC5H4COO)2.Within the framework,two kinds of different manganese atoms in a distorted octahedral geometry were incorporated into the layers and the ferocenedicarboxylato group existed as a synperiplanar conformation and tridentate-bridging mode connecting three manganese atoms.Manganese atoms were connected with oxygen atoms to form a two-dimensional inner layer with the ferrocenyl groups arranged along two sides of the inner layer,thus forming the sandwich-like coordination polymers.EDX indicated the microspheres contained Mn,Fe,C and O,and C-O stretching frequency shifting from 1687 cm-1 for the precursor to 1581.7 cm-1 for the product from FT-IR spectra confirmed the formation of coordination polymer.TGA showed the coordination polymer microspheres had good thermal stability up to at least 319℃.