Tuning of molecular qubits: very long coherence and spin-lattice relaxation times

We report a pulsed EPR study on different transition metal phthalocyanines, elucidating the dependence of spin relaxation on solvent, ligand and metal ion. Coherence times of >40 mu s and spin-lattice relaxation times of up to 2 s were found. Minimization of SOMO-environment overlap leads to increased coherence times.