The Electrochemical Properties Of Cobaltocenium Phosphine Ligands And Their Complexes

Compared with ferrocene, cobaltocenium is also a stable structure with 18 electrons, so the cobaltocenium phosphine ligands is a good skeleton which can be a disubstituted symmetric chelating ligand, what’s more, the cobaltocenium-phosphine ligands and their derivatives can be used as redox mediums and electronic storage media, thus it is necessary to detect the electrochemical behaviors of them. This paper have comprehensive studied the electrochemical behaviors of the phosphine ligands based on the backbone of cobaltocenium and a series of their metal coordination compounds, as follows:1.Mainly used cyclic voltammetry and square wave voltammetry to study the electrochemical behaviours of 2-1 and a series of the phosphine chalcogenide (2-2; 2-3; 2-4), while different solvents and electrolytes were used for compareing, the results showed that cobaltocenium monophenylphosphino dimerization reaction probablely occur, but when the phosphorus lone pair electrons coordinate with the oxygen, sulfur and selenium, they all showed a pair of single peaks. At last, through the method of bulk electrolysis for 2-1, we use coulmetry ultraviolet spectra technology to test the solvents before and after the electrolysis, there isn’t any modification emerged in the cyclic voltammetry, however, the ultraviolet spectra showed that there is a new absorption peak appeared atλ,=335nm after the electrolysis.2.Based on the study of 2-1, cyclic voltammetry and square wave voltammetry were used to investigated the electrochemical behavior of disubstituted diphenylphosphino(3-1) and a series of phosphine chalcogenide(3-1,3-3,3-4), and the different substituents (isopropyl, isobutyl, tert-butyl and cyclohexyl) phosphine, the potential involved chalcogenide all appeared positive shift; the effection of different substituents to the potential of Co(Ⅲ)/(Ⅱ) is concerned with the electrondonating capacity of substituents. Beyond that, the assay of ultraviolet spectra through electrolysis and electrolytic substances before and after the bulk electrolysis with coulometry be accomplished, the potential occurred a positive shift of about 259mV, but the UV spectrum does not appear much changes.3.The electrochemical techniques of cyclic voltammetry and square wave voltammetry were used to study the electrochemical properties of transition metal palladium, platinum and ruthenium and cobalt cationic ferrocene phosphine ligands, the results showed that after coordinated with the metals, the redox potentials of them all showed positive shift., especially 4-9[dppc+(AuCl)2PF6-], the positive shift reached to 564mV.