Spin-dependent charge transmission through chiral 2T3N self-assembled monolayer on Au

A gold surface is functionalized by chemisorption of the enantiopure N,N'-bis-[2,2';5',2'']tert-thiophene-5-yl methylcyclohexane-1,2-diamine (2T3N), a chiral oligothiophene derivative, via overnight incubation in a 2T3N ethanol solution. The Au|2T3N interface is characterized by x-ray photoelectron circular dichroism and comparing x-ray photoemission spectroscopy and electro-desorption results. Charge transmission at the Au|2T3N| solution interface is characterized by recording the cyclic voltammetry of the Fe(III)/Fe(II) reversible redox couple, finding a charge transfer rate constant, k degrees, variation from 1 x 10(-1) to 3.3 x 10(-2) cm s(-1), when comparing the bare Au and the Au|2T3N interfaces, respectively. The "anomalous" high value of k degrees found for the chiral Au|2T3N interface can be rationalized on the basis of the chiral-induced spin selectivity effect, as further proved by magnetic-conductive atomic force microscopy measurements at room temperature. A spin polarization of about 30% is found.