  We use scanning tunneling microscopy and spectroscopy to investigate
structural and electronic properties of tetracyanonaphtho-quinodimethane (TNAP)
based metal-organic networks on a superconducting Pb(111) surface. At low
temperatures, the TNAP molecules form densely packed islands. When deposited at
room temperature, Pb adatoms are incorporated into fourfold bonding nodes with
the TNAP molecules leading to long-range ordered porous structures.
Co-deposition of NaCl with TNAP yields a Na source for an ionically bonded
Na-TNAP structure. Fourfold bonding motifs are also created by Fe atoms with
the cyano terminations of TNAP. However, the structures are irregular and do
not sustain the formation of long-range ordered networks. Some Fe centers with
molecules surrounded in a local C2 symmetry exhibit Shiba states as a
fingerprint of a magnetic interaction with the superconducting surface.
