In conclusion, the results presented support our proposal that interlocked molecules can provide a platform for the developme nt of ligands for use in SIMs and that computational modelling can, in principle, be used to direct this process. While interlocked structures such as hybrid organic-inorganic rotaxanes have been proposed as promising architectures for qubits, interlocked complexes [Co(1-3)](ClO4)2 are the first examples to show field-induced SIM behavior. Our combined EPR spectroscopic and magnetic measurement approach enabled us to determine the magnetic parameters, including the rhombic anisotropy (E/D = 0.10-0.22) and HS:LS spin state populations, and the magnitude of the zero-field splitting values, with confidence. It is noteworthy that [Co(1-3)](ClO4)2 exhibit remarkably large negative D values compared to other penta-coordinated cobalt complexes reported (summarized in Table ) that were found to exhibit SIM behavior, such as bis(imino)pyridine pincer cobalt complexes (D values of -28 cm -1 ) and [Co(phen)(DMSO)Cl2] (D ~ -17 cm -1 ). Although [Co(1-3)](ClO4)2 all exhibited slow relaxation of the magnetization in the presence of a magnetic field, there is clearly room for improvement in tuning the structures to achieve SIM behavior at higher temperature and in the absence of a magnetic field.