Zwitterionic form of Ugi amine H-phosphinic acid: Structure and electrochemical properties

Abstract

Ugi amine H-phosphinic acid was prepared by hydrolysis of 1-dichlorophosphanyl-2-N,N-dimethylaminomethylferrocene (1). The formation of the zwitterionic form of Ugi amine H-phosphinic acid (2) was clearly demonstrated by NMR, X-ray single crystal diffraction studies and electrochemical measurements. It was shown for the first time that Ugi amine H-phosphinic acid, unlike other monophosphinates reported in the literature, does not show double oxidation peaks, which clearly indicates the presence of a single form in solution. It is shown that the oxidative potential of 2 is more positive than that of other monophosphinates, since in solution the substance exists completely in the zwitterionic form.

Keywords

• Ugi’s amine
• H-phosphinic acid
• Zwitterionic form
• Electrochemical properties