The First Hexadithienylethene‐Substituted Tris(bipyridine)metal Complexes as Quadratic NLO Photoswitches: Combined Experimental and DFT Studies

Flip the NLO switch! A straightforward access to hexadithienylethene‐based photochromes by using a coordination‐chemistry approach through the combination of bis(dithienylethene)bipyridyl ligands and metal ions (M=Zn, Fe) is reported. The photostability of the isomeric forms of the iron(II) complexes allows the photoswitching of second‐order nonlinear optical (NLO) responses (see figure), and the results are rationalized with the help of time‐dependent density functional theory.