Identification of single photoswitchable molecules in nanopores of silica xerogels using powder diffraction

摘要

Single photoswitchable molecules of (CN_3H_6) _2[Fe(CN)_5NO] (GuNP) are embedded into nanopores of an SiO2 xerogel. It is shown that it is possible to identify the structural motif (fingerprint) of the embedded complex by analyzing neutron powder diffraction data in a limited Q range (Q < 37 nm~(-1)) using the Debye approach. The structural study reveals that the pores are occupied by GuNP monomers with a fill factor of 60-80%. The mutual arrangement of the anion and cations in the GuNP monomer is slightly changed (～1% elongation), while the bond lengths within the anion and cation are changed by less than 0.2% with respect to the single-crystalline form of GuNP.