WCo Discrete Complex Exhibiting Photo‐ and Thermo‐Induced Magnetisation

Molecular (photo)switch : A WCo photomagnetic discrete complex can be prepared through the self‐assembly of preformed building blocks. [Co(bik) 3 ][{W(CN) 8 } 3 {Co(bik) 2 } 3 ]⋅2 H 2 O⋅13 CH 3 CN (see figure) exhibits a thermally‐induced electron‐transfer‐coupled spin transition between the two states: ${{{\rm {\rm Co}}{{{\rm {\rm II}}\hfill \atop {\rm {\rm HS}}\hfill}}}}$ W V ↔ ${{{\rm {\rm Co}}{{{\rm {\rm III}}\hfill \atop {\rm {\rm LS}}\hfill}}}}$ W IV . It also shows photomagnetic effects at low temperature.