Systematic dimensional reduction of the layered β-FeSe structure by solvothermal synthesis.

Dimensional reduction of superconducting anti PbO-type iron selenide has been achieved by terminating the tetragonal square layers of FeSe tetrahedra by ethylenediamine (en) ligands. We obtained three new structures in the Fe-Se-en system. FeSe(en) contains FeSe single chains bridged via Fe(en) complexes.