  The role of Chemistry in the road towards quantum devices is the design of
elementary pieces with a built-in function. A brilliant example is the use of
molecular transistors as nuclear spin detectors, which, up to now, has been
implemented only on [TbPc$_2$]$^-$. We argue that this is an artificial
constraint and critically discuss the limitations of current theoretical
approaches to assess the potential of molecules for their use in spintronics.
In connection with this, we review the recent progress in the preparation of
highly coherent spin qubits based on vanadium dithiolate complexes and argue
that the use of vanadyl dithiolates as single molecule transistors to read and
control a triple nuclear spin qubit could give rise to new phenomena, notably
including a low-current nuclear spin detection scheme by means of a spin valve
effect.
