The undecanuclear complex in [Fe(III)(11)(mu(4)-O)(3)(mu(3)-O)(4)(L)(3)(mu-O(2)CCMe(3))(12)]Cl.5MeCN has been synthesized and characterized by single-crystal X-ray crystallography. Mossbauer spectroscopy and bulk susceptibility studies reveal that the complex has an S = (13)/(2) spin ground state and exhibits single-molecule-magnet behavior.