The control of the charge- and spin state of single molecules is key for the design of mo­le­cu­lar elec­tro­nic and spin­tro­nic de­vi­ces.  For swit­ching the spin or mag­ne­tic state of mo­le­cules two prin­ci­ples have been used in the past:  (1) atoms or small mo­le­cu­les were ad­ded to and re­mo­ved from the host mo­le­cule or (2) by mo­di­fying the shape of mo­le­cu­les which can exist in more than one con­fi­gu­ra­tion.  The re­a­li­za­tion of both me­thods is ra­ther dif­fi­cult.  In co­ope­ration with theo­rists around Prof. Giorgio Sangiovanni (TP I), in a re­cent pub­li­ca­tion our group presented an al­ter­na­tive way to achieve mul­tiple and re­ver­si­bly switchable spin states in a single mo­le­cu­les.   These re­sults show that a bi­stable mo­le­cu­lar state can be achie­ved by po­si­tio­ning single man­ga­nese phthalo­cyanine (MnPc) mo­le­cu­le on top of an anti­phase boun­da­ry of the (3×3)-recon­struc­ted sur­face alloy of bismuth on Ag(111).   In this environment we can switch single molecules bet­ween a high- and a low-spin state by using the elec­tric field of a sharp STM tip.  The result has been pub­lished in npj Quantum Materials.