Rational design of potential spin qubits manipulated by the valence tautomerism mechanism: quantum-chemical modeling of the trinuclear transition metal complexes with bischelate linkers

A new series of transition metal coordination compounds capable of manifesting the properties of logical elements of quantum computers has been computationally designed using the DFT UB3LYP*/6-311++G(d,p) calculations. The trinuclear 1 : 2 adducts formed by Cu-II and Co-II acetylacetonates functionalized with di-o-quinone moieties and CoII diketonates have been shown to meet the principal requirements (well-defined and weakly coupled paramagnetic centers) for the compounds with the potential of spin qubits and also have properties, such as thermodynamic stability, low energy gap between electromeric forms and thermally overcoming energy barriers to their spin state switching transition, ensuring the occurrence of valence tautomeric rearrangements as an additional means for modulation of magnetic characteristics of the designed trinuclear complexes.