Hydrogen bond networks in five- and eight-membered palladium and platinum complexes derived from bis(2-aminophenyl)ether and bis(2-aminophenyl)thioether ligands

The reaction of [MII(MeCN)2Cl2] (M = Pd, Pt) with the diamino ligands either bis(2-aminophenyl)ether or bis(2-aminophenyl)thioether {(NH2-C6H4)2D} [D = O (L1); D = S (L2)] yielded neutral coordination complexes of general formulae [M(Ln)Cl2] [M = Pd, n = 1 (1); Pt, n = 1 (2); Pd, n = 2 (3); Pd, n = 2 (4); Pt, n = 2 (5). The reaction of L2 with K2[PtCl6] promoted the mono-deprotonation of the diamino ligand to yield the neutral complex [PtIV{(NH2-C6H4)S(NH-C6H4)}Cl3] (6); when the H2[PtCl6] acid was used an ionic complex [PtIV(L2)Cl3]Cl (7) was obtained. All complexes were characterized by NMR in solution, vibrational spectroscopy, and by X-ray diffraction studies. The molecular structures of the complexes revealed different coordination patterns of the diamino ligands; L1 just displayed a κ2N mode meanwhile L2 exhibited a wide variety of patterns (κ2N, κNκS, and κ2NκS) forming chelate rings of five- or eight-members. The presence of N–H functions in the ligand moieties enhanced the formation of extended hydrogen-bond networks; these supramolecular arrangements were mainly discussed at unitary and binary levels and sorted according to the molecular coordination patterns observed.

Graphical abstractThe synthesis and structural characterization of palladium and platinum complexes derived from {(NH2-C6H4)2D} ligands [D = O (L1), S (L2)] is described. Molecular structures of 1 and 2 by X-ray diffraction studies showed the κ2N coordination mode of 1 toward the metallic ions. 2 displayed a more versatile coordinating behavior; κ2N, κN,κS, and κ2N,κS modes were observed in the molecular structures of 3–7. In solid state the N–H–Cl interactions enhanced the formation of captivating supramolecular associations.Figure optionsDownload full-size imageDownload as PowerPoint slide