Designed Topology and Site-Selective Metal Composition in Tetranuclear [MM’···M’M] Linear Complexes

摘要

The ligand 1,3-bisACHTUNGTRENUNG[3-oxo-3-(2- hydroxyphenyl)propionyl]benzene (H4L), designed to align transition metals into tetranuclear linear molecules, reacts with MII salts (M=Ni, Co, Cu) to yield complexes with the expected [MM···MM] topology. The novel complexes [Co4L2(py)6] (2; py= pyridine) and [Na(py)2]ACHTUNGTRENUNG[Cu4L2(py)4]- ACHTUNGTRENUNG(ClO4) (3) have been crystallographically characterised. The metal sites in complexes 2 and 3, together with previously characterised [Ni4L2(py)6] (1), favour different coordination geometries. These have been exploited for the deliberate synthesis of the heterometallic complex [Cu2Ni2L2(py)6] (4). Complexes 1, 2, 3 and 4 exhibit antiferromagnetic interactions between pairs of metals within each cluster, leading to S=0 spin ground states, except for the latter cluster, which features two quasiindependent S=1=2 moieties within the molecule. Complex 4 gathers the structural and physical conditions, thus allowing it to be considered as prototype of a two-qbit quantum gate.