Relationships between basicity, redox behaviour of ferrocenylamines and their reactivity with Pt[II] compounds

pK(b) values for the ferrocenylamines, [(eta-C5H4(CH2)(x)NH2)FeCp] x = 1, 2, 3; [(eta-C5H4CH2NHR)FeCp] R = Me, 4, Ph, 5; {[eta-C5K4CHR'NR2]FeCp} R'/R = H/Me, 6, R'/R = H/Ph, 7, Me/Me, 8; [{eta-C5H4CHRNMe2)(2)Fe] R = H 9, Me 10; [{1,2 eta-C5H3(CH2NMe2)(PPh2)}FeCp] 11, {1,2 eta-C5H3[CH(Me)NMe2](PR2}}Fe[eta-C5H4(PPh2)(n)] n = 0, R = Pr-i 12, Ph 13, n = 1, R = Me 14, are correlated with inductive, neighbouring group and steric effects. Corresponding salts have been synthesised. The pK(b) has a marked influence on their chemistry. Protonation competes with complexation but cis-PtCl2L2 L = 1-3, 5, 7, and cis-Pt(N-N)Cl-2 L = 8, 9, have been characterised. Two reversible couples [Fc(+)A/FcA], [Fc(+)AH(+)/FcAH(+)] (A = amine function) and an irreversible oxidation/protonation of A are linked by a EECE mechanism, but potentials for the first two are independent of the amine and similar to ferrocene. Nucleophilic attack by ferrocenylamines at the nitrile, protonation and ligand substitution are all observed with cis-[PtCl2(NCR)(2)]. (C) 1998 Elsevier Science S.A. All rights reserved.