Five-Coordinated Dysprosium Single-Molecule Magnet Functionalized by the SMe Group.

A five-coordinate mononuclear Dy(III) complex with a C 4 v geometry (square-pyramid), [Dy(X)(DBP) 2 (TMG(H)) 2 ] [X = 3-(methylthio)-1-propoxide, DBP = 2,6-di- tert -butylphenoxide, and TMG(H) = 1,1,3,3-tetramethylguanidine] ( 1 ), was designed and synthesized. The complex displays a large anisotropy barrier of 432 cm -1 in the absence of a dc magnetic field benefiting from the strong interaction between the phenolate and Dy(III) ion. Ab initio calculations reveal that the most possible relaxation pathway is going through the second excited state. The terminal SMe group in the apical position furnishes the possibility of depositing it on the Au surface by the strong Au-S bond.