[摘要]：The deposition of Mn12 single mol. magnets on Au surfaces was studied for the 1st time using combined x-ray absorption spectroscopy (XAS) and x-ray MCD (XMCD) methods at low temp. The ability of the proposed approach to probe the electronic structure and magnetism of Mn12 complexes without significant sample damage was successfully checked on bulk samples. Detailed information on the oxidn. state and magnetic polarization of Mn ions in the adsorbates was obtained from XAS and XMCD spectra, resp. Partial redn. of metal ions to MnII was clearly obsd. upon deposition on Au(111) of 2 different Mn12 derivs. bearing 16-acetylthio-hexadecanoate and 4-(methylthio)benzoate ligands. The av. oxidn. state, as well as the relative proportions of MnII, MnIII and MnIV species, are strongly influenced by the deposition protocol. Also, the local magnetic polarizations are significantly decreased as compared with bulk Mn12 samples. The results highlight an utmost redox instability of Mn12 complexes at Au surfaces, presumably accompanied by structural rearrangements, which cannot be easily revealed by std. surface anal. based on x-ray photoelectron spectros- copy and scanning tunnelling microscopy.
