A. Benito et al., FERROCENE CONTAINING CHELATING LIGANDS .2. SYNTHESIS, CHARACTERIZATION, ELECTROCHEMICAL-BEHAVIOR AND CRYSTAL-STRUCTURE OF 2-FERROCENYLMMTHYLAMINO-BENZOIC ACID, Inorganica Chimica Acta, 210(2), 1993, pp. 233-236
Ferrocenecarboxaldehyde reacts with 2-amino-benzoic acid in benzene to
give the Schiff base derivative 2-ferrocenylmethylidenimino-benzoic a
cid (eta5-C5H5)Fe[(eta5-C5H4)-CH= N-C6H4-COOH] (1). 1 is stable as a s
olid but easily hydrolyzes in solution. Selective hydrogenation of the
imine group can be performed using NaBH4 to obtain the parent amine (
eta5-C5H4)Fe[eta5-C5H4)-CH2-NH-C6H4-COOH]. (2). The molecular structur
e of 2 has been determined by single-crystal X-ray methods. It crystal
lizes in the space group P2(1)/c, a=11.077(9), b=7.430(2), c=19.194(9)
angstrom, beta=111.02(4)-degrees, V=1474(2) angstrom3, Z=4. Refinemen
t of the structure gave final R factor of 0.038 (R(w)=0.035) for 1106
unique reflections having F(o)2 > 2.8sigma(F(o)2). 2 is stable both in
the solid state and solution, and a potential chelating N,O-donor lig
and containing a ferrocenyl group. A one-electron oxidation process wa
s found by cyclic voltammetry (0.1 M NBun4PF6, CH2Cl2) for 1 and 2 at
0.74 and 0.51 V, respectively.