title: Multiple-decker and ring sandwich formation of manganese-benzene organometallic cluster anions: MnnBzn-(n = 1-5 and 18).
abstract: Organometallic multiple-decker sandwich clusters are topics of great interest due to their unique electronic and magnetic properties originating from anisotropic structures. We report a joint anion photoelectron spectroscopic and computational study on a new family of manganese (Mn)-benzene (Bz) anionic clusters MnnBzn-. In stark contrast to the most widely studied vanadium-Bz sandwich clusters, it is found that MnnBzn-(n = 1-5) clusters exhibit unprecedented multiple-decker structures with a tilted Mn-Bz stacking and a monotonically increasing behavior of their high spin multiplicities. Furthermore, a couple of closed ring forms of Mn18Bz18-and its neutral state are computationally anticipated as an intriguing "cluster of Mn1Bz1clusters" in which the neutral Mn18Bz18has extremely high C18hsymmetry with an uncommon spin state of 2S + 1 = 55. The extensively delocalized electron environment of Mn18Bz18allows the simple Hückel model to reveal the strong intra-atomic exchange interactions within the Mn 3d electrons.
authors.affiliation: Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan. nakajima@chem.keio.ac.jp.
authors.forename: Tsugunosuke
authors.initials: T
authors.lastname: Masubuchi
authors.affiliation: Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan. nakajima@chem.keio.ac.jp and JST, ERATO, Nakajima Designer Nanocluster Assembly Project, 3-2-1 Sakado, Takatsu-ku, Kawasaki 213-0012, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Iwasa
authors.affiliation: Department of Chemistry, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan. nakajima@chem.keio.ac.jp and JST, ERATO, Nakajima Designer Nanocluster Assembly Project, 3-2-1 Sakado, Takatsu-ku, Kawasaki 213-0012, Japan and Keio Institute of Pure and Applied Sciences (KiPAS), Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama 223-8522, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Nakajima