A Phosphorus Supported Multisite Coordinating Tris Hydrazone P(S)[N(Me)N=CH-C6H4-o-OH]3 as an Efficient Ligand for the Assembly of Trinuclear Metal Complexes: Synthesis, Structure, and Magnetism

A phosphorus supported multisite coordinating ligand P(S)[N(Me)N=CH-C6H4-o-OH]3 (2) was prepared by the condensation of the phosphorus tris hydrazide P(S)[N(Me)NH2]3 (1) with o-hydroxybenzaldehyde. The reaction of 2 with M(OAc)2·xH2O (M = Mn, Co, Ni, x = 4; M = Zn, x = 2) afforded neutral trinuclear complexes {P(S)[N(Me)N=CH-C6H4-o-O]3}2M3 [M = Mn (3), Co (4), Ni (5), and Zn (6)]. The X-ray crystal structures of compounds 2-6 have been determined. The structures of 3-6 reveal that the trinculear metal assemblies are nearly linear. The two terminal metal ions in a given assembly have an N3O3 ligand environment in a distorted octahedral geometry while the central metal ion has an O6 ligand environment also in a slightly distorted octahedral geometry. In all the complexes, ligand 2 coordinates to the metal ions through three imino nitrogens and three phenolate oxygens; the latter act as bridging ligands to connect the terminal and central metal ions. The compounds 2-6 also show intermolecular C-H···S=P contacts in the solid-state which lead to the formation of polymeric supramolecular architectures.