Crystal structure and spectra of the mixed-ligands complex 1-(2-thenoyl)-2-(2,2′-dipyridyl methylene)hydrazino-acetato lead (II)

Abstract

Abstract The crystal structure of the title compound has been determined from three-dimensional X-ray diffraction data. The crystals are triclinic, space group P[unk], with a = 11.218(1) Å, b = 11.680(1) Å, c = 15.360(1) Å, α = 93.422(5)°, β = 110.575(8)°, γ = 90.951(6)°, V = 1879.36 Å3, Z = 2. The structure was solved by the heavy-atom method and refined by least-squares to a final R = 0.043 (Rw = 0.044) for 4897 observed unique reflections [F o > 5σ(F o)]. The complex consists of dimeric (C18H14N4O3PbS)2 units. Each Pb atom is coordinated by one 1-(2-thenoyl)-2-(2,2′-dipyridyl methylene)hydrazine ligand, (TDPH), and one acetyl ligand. The TDPH ligand behaves as a tridentate chelate by linking to Pb through the thenoyl oxygen, the azomethine nitrogen and one pyridine nitrogen [mean metal-to-ligand distances: Pb–N(azomethine) 2.492(5) Å, Pb–N(pyridine) 2.640(6) Å and Pb–O(thenoyl) 2.370(4) Å]. The acetyl group, on the other hand, acts as a bibentate chelate with one Pb–O distance significantly larger than the other [short bond distance range: 2.275(1)–2.320(7) Å; long bond distance range: 2.709(7)–3.354(9) Å]. Moreover, there is an additional Pb…O interaction with the acetyl group of the other member of the dimeric unit, giving rise to a strongly distorted pentagonal pyramidal environment around the metal atom with the thenoyl oxygen lying at its apex. The IR and electronic spectra are in accordance with the established structure from the X-ray data. Conductivity measurements indicate the non-electrolytic character of the complex.