Successful grafting of isolated molecular Cr7Ni rings on Au(111) surface

We deeply investigated the properties of submonolayer distributions of isolated molecular Cr7Ni ringsdeposited on Au111 by liquid phase. X-ray absorption spectra measured at the Cr and Ni L2,3 edges show thatthe grafting of the Cr7Ni rings onto the gold surface does not affect the oxidation state and the local symmetryof the Cr and Ni sites. The circular dichroism shows a change in sign of the Ni magnetic moment. This is dueto a reduction in the exchange coupling constants that, however, preserves the structure of the low-energylevels of the grafted rings, as corroborated by spin-Hamiltonian simulations and comparison with measure-ments on bulk sample. Density-functional theory calculations show that the Ni-Cr bond gets weaker with slightring distortion suggesting possible explanation for the observed magnetic behavior. These results show thatcomplex magnetic molecules can be grafted onto surfaces, and that changes in their magnetic behavior must beexamined in individual cases.