Propagation of spin information at supra-molecular scale through hetero-aromatic linkers

We report an in-depth study on how spin information propagates at supramolecular scale through a family of heteroaromatic linkers. By density-functional theory calculations, we rationalize the behavior of a series of Cr7Ni dimers for which we are able to systematically change the aromatic linker thus tuning the strength of the magnetic interaction, as experimentally shown by low temperature micro-SQUID and specific heat measurements. We also predict a cosa2 dependence of the magnetic coupling on the twisting angle between the aromatic cycles in bicyclic linkers, a mechanism parallel to charge transport on similar systems [ L. Venkataraman et al. Nature (London) 442 904 (2006)].