Investigation of ternary Co(n)CN(-1/0) (n = 1-5) clusters by density functional calculations

The neutral and anionic Co(n)CN (n = 1-5) clusters were investigated using density functional calculations. The most stable structures of neutral and anionic Co(n)CN (n = 1-5) clusters have been identified. In these structures, the CN radical retains its integrity as a structural unit. For anionic Co(n)CN(-) (n = 1-5) and neutral Co(n)CN (n = 1-2) clusters, the CN prefers to be adsorbed on the top sites of Co(n) clusters via the C terminal, forming a linear or quasi-linear N-C-Co structure. For neutral Co(n)CN (n = 3-5) clusters, the CN is adsorbed on the bridge sites of Co(n) (n = 3-5) by both C and N atoms. Compared to the free CN radical calculated at the same level, the C-N stretching frequencies of neutral Co(n)CN (n = 3-5) are red-shifted while they are blue-shifted for neutral Co(n)CN (n = 1-2). The adiabatic and vertical detachment energies of anionic Co(n)CN(-) (n = 1-5) clusters are calculated based on density functional calculations. In addition, the most favored dissociation channels of neutral and anionic Co(n)CN (n = 1-5) clusters are determined by calculating the dissociation energies of various possible dissociation pathways.