  One-dimensional metal-organic chains often possess a complex magnetic
structure susceptible to be modified by a alteration of their chemical
composition. The possibility to tune their magnetic properties provides an
interesting playground to explore quasiparticle interactions in low-dimensional
systems. Despite the great effort invested so far, a detailed understanding of
the interactions governing the electronic and magnetic properties of the
low-dimensional systems is still incomplete. One of the reasons is the limited
ability to characterize their magnetic properties at the atomic scale. Here, we
provide a comprehensive study of the magnetic properties of metal-organic
one-dimensional (1D) coordination polymers consisting of
2,5-diamino-1,4-benzoquinonediimine ligands coordinated with Co or Cr atoms
synthesized in ultra-high vacuum conditions on a Au(111) surface. A combination
of an integral X-ray spectroscopy with local-probe inelastic electron tunneling
spectroscopy corroborated by multiplet analysis, density functional theory, and
inelastic electron tunneling simulations enable us to obtain essential
information about their magnetic structure, including the spin magnitude and
orientation at the magnetic atoms, as well as the magnetic anisotropy.
