Spectroscopic, Electrochemistry and Thermal Properties of Mono- and 1,1′-Disubstituted 1,2,3-Triazolylferrocene Derivatives

A series of mono-and 1,1'-disubstituted 1,2,3-triazolylferrocene derivatives have been synthesized and characterized. In UV-Vis spectroscopy, 1,1'-disubstituted compounds have the larger molar absorption coefficient than those of monosubstituted compounds. The fluorescence intensity weakened with increasing the number of alkoxy chain and further weakened after introduction of the highly electronegative chlorine atom. All new compounds showed quasireversible redox process. The potentials for 1,1'-disubstituted 1,2,3-triazolylferrocene derivatives anodically shifted about 150 mV compared with those of monosubstituted compounds, indicating harder oxidation by loss of an electron for the former. These compounds started to decompose at about 285 similar to 305 degrees C. The 1,2,3-triazolylferrocene derivative with one terminal alkoxy chain had high melting point, and suffered from degradation reaction before changing into isotropic liquid, and those with multiterminal alkoxy chains showed either simple melting and freezing process or crystal polymorphic phase to isotropic liquid phase transitions in the heating and cooling cycles.