Planar wheel-type M©BnHn2−/−/0 clusters (M = Cr, Mn and Fe for dianion, anion and neutral, respectively; n = 6 and 7)

Abstract

We adopted a new “electronic” strategy that is adding two electrons into the d_z² orbital of the central M atom to form a lone pair, which is in contrast to the Hoffmann’s “electronic” strategy that is delocalizing the lone pair on the center atom, to turn the bowl-type MB_nH_n^0/+ (M = Cr and Mn; n = 6 and 7) clusters into planar wheel-type M©B_nH_n^2−/− clusters. Their isoelectronic neutral clusters, Fe©B₆H₆ and Fe©B₇H₇, also possess planar wheel-type structures. The large binding energy, vertical ionization potential, and vertical electron affinity indicate that the planar wheel-type M©B_nH_n^2−/− clusters are chemically stable. This study may open up a new area in coordination chemistry for planar hexa- and hepta-coordinate transition metal and we expect further experimental explorations of synthesis and potential applications.