Chemistry of palladium(II) with bis(3-amidopyridine) ligands

The coordination chemistry of palladium(II) with bis(3-amidopyridine) ligands [LL = 2,6-C5H3N(CONH-3-C5H4N)(2), 1; 1,3-C6H4(CONH-3-C5H4N)(2), 2; 1,3-C6H4(CONMe-3-C5H4N)(2), 3; 2,5-C4H2S(CONMe-3-C5H4N)(2), 4] has been investigated. Neutral binuclear macrocyclic complexes trans,trans-[Pd2X4(mu-LL)(2)] have been characterized with X = Cl or Br and LL = 1. Cationic complexes have been characterized as mononuclear bis(chelate) derivatives [Pd(LL)(2)](2+), when LL = 3 or 4, but a lantern complex [Pd-2(mu-LL)(4)](4+), when LL = 2. The tendency for chelation versus bridging coordination of the flexible ligands 1-4 is analyzed in terms of substituent effects on the preferred ligand conformations. In the dipalladium complexes, the macrocycle or lantern structure can accommodate guest molecules. (C) 2016 Elsevier B.V. All rights reserved.