Tailored homo- and hetero- lanthanide porphyrin dimers: a synthetic strategy for integrating multiple spintronic functionalities into a single molecule.

We present the design, synthesis and magnetic properties of molecular magnetic systems that contain all elements necessary for spin-valve control in molecular spintronic devices in a single molecule. We investigate the static and dynamic magnetic properties and quantum spin properties of butadiyne-linked homo-and hetero-nuclear lanthanide-porphyrin dimers. A heterometallated porphyrin dimer containing both Tb-III and Dy-III centres is created rationally by the stepwise oxidative homocoupling of distinct lanthanide-porphyrin monomers. Tb-III and Dy-III mononuclear porphyrin complexes, homodimers and heterodimers all exhibit slow magnetic relaxation below 10 kelvin under a static magnetic field. The coherence times for Gd-III porphyrin monomers and dimers are found to be in excess of 3.0 mu s at 2 K, allowing distinct magnetic manipulations in low temperature transport experiments.