Electrochemical anion recognition by redox-responsive unnatural amino acid derivatives; the X-ray crystal structure of N-ferrocenoyl glycine methyl ester, ( η5-C 5H 5)Fe( η5-C 5H 4)CONHCH 2COOMe

Abstract

N-Ferrocenoyl glycine ester derivatives FcCONHCH 2COOR (Fc=( η 5-C 5H 5)Fe( η 5-C 5H 4); R=methyl ( 1), ethyl ( 2) and benzyl ( 3)) have been prepared by coupling ferrocene carboxylic acid to a series of glycine esters using 1,3-dicyclohexylcarbodiimide (DCC), 1-hydroxybenzotriazole (HOBT) and Et 3N in CH 2Cl 2. The electrochemical anion sensing using a platinum microdisk working electrode of these N-ferrocenoyl glycine ester derivatives is reported. The crystal structure of 1 has been determined; principal dimensions are amide N(H)CO 1.229(3) Å, ester CO 1.183(3) Å with N–H⋯OC(amide) as the primary intermolecular hydrogen bond, N⋯O 2.804(3) Å.