Investigation of the Structures and Chemical Bonding of Mn 2 Ge 6 - and Mn 2 Ge 7 - Clusters via Anion Photoelectron Spectroscopy and Theoretical Calculations.

We present joint anion photoelectron spectroscopy and theoretical studies for Mn 2 Ge 6 - and Mn 2 Ge 7 - . Experimental results show that Mn 2 Ge 6 - and Mn 2 Ge 7 - have vertical electron detachment energies of 2.58 ± 0.08 and 2.88 ± 0.08 eV, respectively. Both Mn 2 Ge 6 - and Mn 2 Ge 6 have C s symmetric structures with a Mn atom attached to a pentagonal bipyramid MnGe 6 . Both Mn 2 Ge 7 - and Mn 2 Ge 7 have C 2 v symmetric structures, which can be considered as two Mn 2 Ge 4 tetragonal bipyramids sharing a MnGeMn face. According to chemical bonding analyses, Mn 2 Ge 6 could be considered as a (Mn II )(MnGe 6 2- ) complex. Theoretical calculations predict that the extension of Mn 2 Ge 7 to Mn 2 n Ge 4 n +3 may be able to produce a new type of Mn-doped germanium nanostructure.