Linker Regulation: Synthesis and Electrochemical Properties of Ferrocene-Decorated Cellulose

Ferrocene-decorated cellulosic materials are usually obtained via a couple of synthetic procedures, which might possibly affect their degree of substitution. In this work, two ferrocene-decorated cellulose esters, connected either by monocarboxylate or by dicarboxylate linkers, have been prepared via one-step reactions by means of esterifying microcrystalline cellulose (MCC) with ferrocenemonocarboxylic acid and 1,1’-ferrocenedicarboxylic acid (FcDA), respectively. Successful surface modification has been confirmed by elemental analysis, Fourier-transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and thermogravimetric measurements. Large retention of the crystalline morphology can be revealed by powder X-ray diffraction, confirming its surface decoration as well. Cyclic voltammetry results of both esters have demonstrated that the winding of the cellulose chains in MCC-FcDA caused by its cross-linking structure might have unfavorable effect for electron transfer, resulting in weaker reversibility of its redox process. Therefore, exploration of a suitable linker might be of great importance to achieve ideal electrochemical properties. Graphic Abstract Two ferrocene-decorated cellulose esters connected either by mono or by dicarboxylate linkers have been synthesized via one-step reactions, exhibiting the more electrochemical reversibility of the monocarboxylate-linked ester.