Tuning Crystal Field and Spin Dynamics in Gd(III) Complexes via Coordination Geometry

Lanthanide-based complexes with high spin are fascinating candidates for realizing spin qubits thanks to their intrinsic multilevel structure, which offers a larger number of accessible states for storing and processing information. Among the 4f series, GdIII, presenting an almost negligible anisotropy and S = 7/2, is particularly interesting for this purpose. Herein, we report on the GdIII-based compound [ZnCl(μ-L)Gd(μ-L)ClZn]PF6 (H2L = N,N′-dimethyl-N,N′-bis(2-hydroxy-3-formyl-5-bromobenzyl)ethylene-diamine), which displays slow relaxation of the magnetization and behaves as a qubit, thereby expanding the still scarce catalogue of Gd-based molecular systems exhibiting both properties. The potential of this system for quantum computing has been explored through Q-band pulsed electron paramagnetic resonance on different diamagnetically diluted derivatives, revealing spin–lattice (T1) and phase memory (Tm) times up to 249.3 and 4.938 μs at 5 K, respectively, and Rabi oscillations persisting up to 120 K.