Synthesis and Electrochemical Behavior of Ferrocenyl beta-Ketoamines FcC(O)CH=C(NH(C6H4-4-R '))R

FcC(O)CH=C(OH)R (1, R= Me; 2, R= Fc; Fc= Fe(eta(5)-C5H4)(eta(5)-C5H5)) reacts with 1-H2N-4-R'-C6H4 (3a, R'= Me; 3b, R`= OMe; 3c, R'= C.N; 3d, R'= F) producing beta-ketoamines FcC(O)CH=C(NH(C6H4-4-R'))R (4a-d, R= Me; 5a-d, R= Fc). Electrochemistry shows that 4a-d possess one (4a: E degrees'= 90 mV; 4b: E degrees'= 80 mV; 4c: E degrees'= 145 mV; 4d: E degrees'= 95 mV) and 5a-d two (5a: E degrees' 1,2= 90, 305 mV; 5b: E degrees' 1,2= 85, 305 mV; 5c: E degrees' 1,2= 155, 360 mV; 5d: E degrees' 1,2= 105, 325 mV) reversible redox processes. In 5a-d electrostatic interactions occur among Fc/[Fc](+) as oxidation progresses, as evidenced by UV/vis-NIR spectroscopy. Compounds 4a,d and 5b,c display an irreversible N-oxidation at 1100-1450 mV, while 4b owns a reversible event at 910 mV. A linear relationship between the s Hammett constants and the E degrees' 1 values exists.